Plasma spectral analyzer

Abstract

A method for real-time, multi-parameter monitoring of fluid quality, comprising the steps of: transiently transforming a continuous stream of the fluid into non-thermal plasma using at least one dielectric barrier discharge plasma chamber; subjecting the liquid to a pressure drop, generating a biphasic liquid-gas stream; continuously ionizing the biphasic liquid-gas stream through a controlled electric field, produced by at least one dielectric barrier electrode; channeling at least one molecular or atomic emission toward a spectrum analysis module; detecting the at least one molecular or atomic emission through the spectrum analysis module; and analyzing the at least one molecular or atomic emission through the spectrum analysis module.

Description

[0001] PLASMA SPECTRAL ANALYZER (PSA) SPECIFICATION Background of the invention Currently there are no solutions for multi-parameter, real-time water quality monitoring, with a high level of reliability, to timely detect contamination. This is the problem that the present invention solves. The origin of the present invention is in the development of a series of plasma chambers used for water treatment, which have the unique ability of partially transforming a continuous liquid stream into non thermal plasma with a sufficient amount of energy density to excite the atoms and molecules in the fluid, allowing them to emit photons at specific wavelengths which are unique to their composition. For the purpose of the invention, modified versions of these plasma chambers were used for capturing the generated light emissions and analyzing their spectrum for detecting the components present in a water stream. This method of transforming a substance into plasma and then recording its emitted light spectrum to get information about its composition is known as spectrometry, and it has been developed in several techniques. Also, due to the characteristics of the hydrodynamic conditions in which these plasma chambers can operate, plasma can be generated and sustained at different energy levels, not requiring to evaporate all the fluid, allowing the detection of compounds like VCs (volatile compounds) and VOCs (volatile organic compounds) (evaporated from the partial vacuum conditions created inside the reactor), and molecular band emission of organic compounds (without decomposing them). With higher energy levels, it is possible to detect compounds such as dissolved ions, and atomic emissions similarly to other spectrometry techniques (e.g., ICP-OES). This energy sweep ability, which allows to tune the ionization process for the detection of specific targets, is a fundamental feature of the present invention. The process carried out by the plasma reactors from which this invention arose, consists in the transient transformation of a continuous stream of liquid into non-thermal plasma, a method comprising subjecting the liquid to an abrupt pressure drop, generating a liquid-gas biphasic stream, which is ionized by a controlled electric field inside a plasma reactor. This process has the unique ability to partially transform a continuous stream of water or other fluid into non-thermal plasma, with a sufficient amount of energy density to excite the atoms and molecules of the fluid, making them emit photons. The purpose of those previous plasma chambers was water disinfection, through multiple plasma effects. For spectral analysis, instead of promoting disinfection mechanisms, the process is aimed at achieving a high degree of ionization —improved light emissions. In the plasma state, ionized atoms and molecules emit light in specific wavelengths. Elements and compounds have spectral signatures by which their presence can be detected, therefore, the composition of a liquid can be determined by the emission lines generated when transformed into plasma. The main distinctive feature of the plasma chamber of the present invention is the optimized mechanism of continuous ionization. The starting point of the development of the first embodiment of the invention was the plasma chamber and supporting components of the base technology, for water disinfection, which has a flow rate of 4 L / min. The spectral analysis is based on an OEM spectrometer and OEM neural network coprocessors. Description of the invention The main difference between the present invention over ICP OES is the use of a portion of the sample, in gaseous phase, instead of a carrier gas. The present invention uses a liquid spectrometry technique based on glow discharge optical emission spectroscopy. It differs from conventional plasma spectroscopy methods by not using a carrier gas to move the analyzed sample. Instead, it uses a nebulization mechanism and the controlled evaporation of a portion of the sample, at low temperature, to introduce the sample in the form of droplets suspended in vapor into a plasma chamber. In the plasma chamber the sample is ionized and: • The emitted photons are processed by an optical emission spectrometer, which delivers data that is analyzed using a neural network. • Molecules break up into positively charged fragments; these fragments are then separated according to their mass-to-charge ratio, for example, by accelerating them and subjecting them to an electric or magnetic field, using a mass spectrometer; which delivers data that is analyzed using a neural network. The present invention can be used in combination with optical emission spectrometry, mass spectrometry and other analytical techniques. In this sense, the invention can analyze the components from a liquid sample that works at low pressure and can create plasma in a partial vacuum. It uses the gases evaporated from the sample as the source of carrier gases, avoiding the injection of external high purity gases (e.g., argon, helium, nitrogen, hydrogen). This allows for better analysis of evaporated gases such as VCs and VOCs. The plasma power injected to the reactor can be regulated, controlling the ionization process, which allows for selective promotion of the ionization of different target components that require different power and ionization energies. This enables the tuning of the detection of different compounds by adjusting the evaporation hence the amount of self-produced “carrier gas” and mass flow, actively controlling vacuum level and thermodynamic parameters such as sample inlet temperature, vessel temperature, and internal devices temperature. Some of the main features of the present invention are: • It works at low pressure, creating plasma in a partial vacuum. • It can use the gases evaporated from the sample as the source of carrier gases, avoiding the injection of external high purity gases. • Allows to regulate the plasma power injected to the reactor, controlling the ionization process, which allows to selectively promote the ionization of different target compounds that require different power and ionization energies tuning by power the detection of different compounds. • It adjusts the amount of carrier gas and mass flow actively controlling vacuum level and thermodynamic parameters such as sample inlet temperature, vessel temperature, internal devices temperature. • RF impedance matcher based on a quartz air cored elevator transformer (RF off the shelf power supply cannot power the plasma reactor at the desired low power levels). transform high current and low voltage (arc discharge) to high voltage and low current (glow discharge). Specifically, the invention refers to a method for real-time, multi-parameter monitoring of fluid quality, comprising the steps of: a) transiently transforming a continuous stream of the fluid into non-thermal plasma using at least one dielectric barrier discharge plasma chamber; b) subjecting the liquid to a pressure drop, generating a biphasic liquid-gas stream; c) continuously ionizing the biphasic liquid-gas stream through a controlled electric field, produced by at least one dielectric barrier electrode; d) channeling at least one molecular or atomic emission toward a spectrum analysis module; e) detecting the at least one molecular or atomic emission through the spectrum analysis module; and f) analyzing the at least one molecular or atomic emission through the spectrum analysis module. According to another embodiment of the invention, the method further comprises, before step d), transmitting the at least one molecular or atomic emission produced in step c) using at least one quartz rod. In this sense, the at least one molecular or atomic emission can correspond to a molecular or atomic photon bands. According to another embodiment of the invention, step d) further comprises channeling the at least one molecular or atomic emission through at least one fiber optic cable to the spectrum analysis module and a light detection unit. According to another embodiment of the invention, the method further comprises detecting the at least one molecular or atomic emission through the light detection unit. According to another embodiment of the invention, the method further comprises determining the type of element corresponding to said at least one molecular or atomic emission through the spectrum analysis module. According to another embodiment of the invention, step a) further comprises producing a series of electrical micro-discharges repeatedly at a frequency of 250 kHz. According to another embodiment of the invention, step c) further comprises varying the electric field according to the required energy level for the non-thermal plasma. According to another embodiment of the invention, step c) is carried out inside the at least one dielectric barrier discharge plasma chamber. According to another embodiment of the invention, step c) is carried out outside the at least one dielectric barrier discharge plasma chamber. According to another embodiment of the invention, the type of element determined in step h) corresponds to one or more of the group consisting of: volatile compounds, organic compounds, volatile organic compounds, dissolved ions, and atomic emissions. According to another embodiment of the invention, the method further comprises connecting the at least one plasma reactor to a bypass pipe, from a larger pipe or tank, to obtain a smaller flow of the target fluid to be analyzed. According to another embodiment of the invention, the method further comprises reinjecting or discarding the analyzed fluid. According to another embodiment of the invention, the method further comprises reinjecting the analyzed fluid when there is no variation of more than 1% in the water composition. According to another embodiment of the invention, the method further comprises discarding the analyzed fluid when there is at least 15% of a determined type of element present in the fluid composition. According to another embodiment of the invention, the method further comprises providing the electrical conditions to maintain a stable plasma condition through electrical means. According to another embodiment of the invention, the method further comprises using electrical energy from a 220 V and 50 Hz power grid, converting it within an adjustable range of continuous voltage between 0 and 400 V, using an AC / DC converter. According to another embodiment of the invention, the method further comprises transforming the continuous voltage signal into a modified sinusoidal alternating signal with an adjustable frequency, using an inverter. According to another embodiment of the invention, the method further comprises filtering the voltage wave and amplifying it through a resonator circuit, formed by an inductor and a capacitor. According to another embodiment of the invention, the method further comprises adjusting the voltage and current levels required by the at least one plasma chamber in the ionization stage, using a transformer. According to another embodiment of the invention, the method further comprises, before step a), nebulizing the fluid to inject it into the dielectric barrier discharge plasma chamber, using an ultrasonic nebulizer. According to another embodiment of the invention, the method further comprises, before step a), applying vacuum in the dielectric barrier discharge plasma chamber, using a vacuum pump. On the other hand, according to a second preferred embodiment of the invention, it is described a system for real-time, multi-parameter monitoring of water quality, comprising: - at least one dielectric barrier discharge plasma chamber, which transiently transforms a continuous stream of the fluid into non-thermal plasma, and which subjects the liquid to a pressure drop, generating a biphasic liquid-gas stream; - at least one dielectric barrier electrode, which continuously ionizes the biphasic liquid-gas stream through a controlled electric field; and - an spectrum analysis module operating in conjunction with a neural network, which channels, detects and analyzes at least one molecular or atomic emission. In this sense, the spectrum analysis module also determines the type of element corresponding to said at least one molecular or atomic emission. According to another embodiment of the invention, the system further comprises at least one quartz rod, which transmits the at least one molecular or atomic emission. According to another embodiment of the invention, the system further comprises at least one fiber optic cable, which channels the at least one molecular or atomic emission. According to another embodiment of the invention, the system further comprises a light detection unit, which detects the at least one molecular or atomic emission. According to another embodiment of the invention, the at least one dielectric barrier discharge plasma chamber comprises a dielectric barrier, which is made of one or more of alumina, zirconium, quartz, and borosilicate glass. According to another embodiment of the invention, the at least one dielectric barrier discharge plasma chamber further comprises a quartz window inserted in its center, which allows connecting the at least one dielectric barrier discharge plasma chamber to the analysis module, through the at least one fiber optic cable. According to another embodiment of the invention, the system further comprises electrical means, which provide the electrical conditions to maintain a stable plasma condition. According to another embodiment of the invention, the electrical means comprise an AC / DC converter, which uses electrical energy from a 220 V and 50 Hz power grid, and converts it within an adjustable range of continuous voltage between 0 and 400 V. According to another embodiment of the invention, the electrical means further comprise an inverter, which transforms the continuous voltage signal into a modified sinusoidal alternating signal with an adjustable frequency. According to another embodiment of the invention, the electrical means further comprise a resonator circuit, which comprises a resonant tank, formed by an inductor and a capacitor, that filters the voltage wave and amplifies it. According to another embodiment of the invention, the electrical means further comprise a transformer, which adjusts the voltage and current levels required by the at least one plasma chamber in the ionization stage. According to another embodiment of the invention, the system further comprises a spectral sensor. According to another embodiment of the invention, the system further comprises an ultrasonic nebulizer, which nebulizes the fluid to inject it into the dielectric barrier discharge plasma chamber. According to another embodiment of the invention, the system further comprises a vacuum pump, which applies vacuum in the dielectric barrier discharge plasma chamber. Brief description of the figures Figure 1 shows the system for real-time multi-parameter monitoring system of water quality, according to a first embodiment of the invention. Figure 2 shows a reactor, according to the first embodiment of the invention. Figure 3 shows the destiny of the output sampling water, according to the first embodiment of the invention. Figures 4 and 5 show another view of the system for real-time multi-parameter monitoring system of water quality, according to the first embodiment of the invention. Figure 6 shows a plasma chamber designed with a Dielectric Barrier Discharge (DBD), according to the first embodiment of the invention. Figure 7 shows different components of an energy supply system to power the plasma chamber, according to the first embodiment of the invention. Figure 8 shows a channel spectral sensor and a neural network processor, according to the first embodiment of the invention. Figure 9 shows a screenshot of a software application, according to a first embodiment of the invention. Figure 10 shows a reconstruction of a spectrum from raw data, based on the manufacturer’s specifications of gain and Full Width at Half Maximum (FWHM) for each channel, according to the first embodiment of the invention. Figures 11, 12 and 13 show several spectral data analyses, according to the first embodiment of the invention. Figure 14 shows spectra identified by a high-resolution spectrometer, according to the first embodiment of the invention. Figure 15 shows a first attempt to measure sodium chloride dissolved in water, according to the first embodiment of the invention. Figure 16 shows spectral lines from water in samples containing volatiles, according to the first embodiment of the invention. Figures 17 and 18 show a plasma chamber designed with a Dielectric Barrier Discharge (DBD), according to a second embodiment of the invention. Figures 19, 20 and 21 show a spectrum for water applying different pressure values, according to the second embodiment of the invention. Figure 22 shows a scattering of Principal Component Analysis (PCA) scores, according to the second embodiment of the invention. Figure 23 shows a PCA loading, according to the second embodiment of the invention. Figure 24 shows a chart related to a control limits in a Hotelling T² analysis and a residual Q, according to the second embodiment of the invention. Figures 25 and 26 show a spectrum for water applying different pressure values, according to the second embodiment of the invention. Figures 27 and 28 show a spectrum for water containing ionic compounds, according to the second embodiment of the invention. Figure 29 shows a spectrum for water containing iron, according to the second embodiment of the invention. Figure 30 shows a spectrum for water containing an ammonium solution, according to the second embodiment of the invention. Figure 31 shows a spectrum for water containing chlorine, according to the second embodiment of the invention. Figure 32 shows a spectrum for water containing bromine, according to the second embodiment of the invention. Figure 33 shows a spectrum for water containing iodine, according to the second embodiment of the invention. Figure 34 shows a spectrum for water which was subjected to ionization, according to the second embodiment of the invention. Figure 35 shows a spectrum for water containing ethanol, according to the second embodiment of the invention. Figure 36 shows a spectrum for water containing isopropyl, according to the second embodiment of the invention. Figure 37 shows a spectrum for water containing acetone, according to the second embodiment of the invention. Figure 38 shows a PCA analysis on the proof-of-concept spectral dataset, according to the second embodiment of the invention. Figure 39 shows a comparison between different proof-of-concept tests, according to the second embodiment of the invention. Figure 40 shows an ultrasonic nozzle, according to a third embodiment of the invention. Figure 41 shows the ultrasonic nozzle connected at the inlet of a plasma chamber, according to the third embodiment of the invention. Figure 42 shows a power generator, according to the third embodiment of the invention. Figure 43 shows a schematic diagram of the third embodiment of the invention. Figure 44 shows an example of the execution output from the program and the range definition structure, according to the third embodiment of the invention. Figure 45 shows a consolidated 2D graph to read the consolidated data and range information, according to the third embodiment of the invention. Figure 46 shows a relationship between the intensities of the H-Alpha and OH emission bands, according to the third embodiment of the invention. Figures 47 to 52 show spectra obtained from the analysis conducted using the third embodiment for each sample containing metal ions that could generate a stable plasma, used in both previous testing sets (first and second embodiments). Figures 53 and 54 show a plasma chamber, according to a fourth embodiment of the invention. Figure 55 shows the main components of the fourth embodiment of the invention. Figure 56 shows a nebulization chamber, according to the fourth embodiment of the invention. Figure 57 shows a plate of the nebulization chamber, according to the fourth embodiment of the invention. Figure 58 shows the nebulization chamber housing a piezoelectric transducer, according to the fourth embodiment of the invention. Figures 59 to 62 show spectra for different water samples, according to the fourth embodiment of the invention. Figure 63 shows the components comprised by the fifth embodiment of the invention. Figures 64 and 65 show an isometric and a front view of the components comprised by the fifth embodiment of the invention. Figures 66 and 67 show isometric views of the reactor together with the cooling system, according to the fifth embodiment of the invention. Figure 68 shows a preferred alternative of the fifth embodiment of the invention, wherein the system is disposed with a mass spectrometer. Figures 69 to 79 show spectra for different water samples, according to the fifth embodiment of the invention. Detailed description of the preferred embodiments Operation principle The first embodiment of the invention comprises a dielectric barrier discharge (DBD) plasma chamber that transforms a continuous water flow into a biphasic stream (gas and droplets) at low pressure. This stream is then ionized by high-frequency electric fields produced by dielectric barrier electrodes outside the reactor to prevent contamination, producing plasma. The molecular and atomic photon band emissions produced depend on the plasma conditions and the composition of the water stream. These emissions are transmitted using high-quality quartz rods with excellent light transmission characteristics over a broad spectrum (UV - VIS - NIR). The light is then channeled through a broad- spectrum fiber optic cable into the spectrum analysis module and a light detection unit, as shown in Figure 1. From a hydrodynamical standpoint, the fluid is accelerated as it enters the reactor, resulting in a two- phase fluid consisting of evaporated gases from the stream and atomized droplets from the liquid portion in a partial vacuum, as illustrated in Figure 2. The emitted light spectrum can be guided through a fiber-optic cable and analyzed using an Emission Spectroscopy method to detect and measure the concentration of contaminants. This allows for real- time water quality analysis. The invention device will be designed to be connected to a by-pass pipe, from a large pipe or tank, to obtain a smaller flow of the target water to be analyzed. Depending on the water use, the water output would be reinjected or discarded. The output sampling water would likely be reinjected when there is no significant variation in the water composition (99% clean water). The output sampling water will be discarded in processes that require it to avoid contamination with plasma reactive species (15% compound A), as illustrated in Figure 3. First embodiment of the invention The invention was implemented in a testing bench configuration, as shown in Figure 4, to carry out spectral acquisition tests, where it is necessary to simulate different scenarios for the operation of the system, for example, power and frequency scanning that operates the electrodes. It can control and generate power pulses and integrates the hydraulic system for sampling supply with the plasma chamber. In addition, one of the purposes of implementing a testing bench is that it allows for the early identification of the challenges of each of the subsystems experimentally and how they influence the overall operation. The design and manufacturing of the testing bench involved the development of customized components, as well as the selection, acquisition and integration of several components in the plasma, spectrometer, hydraulic, electrical and control subsystems, as shown in Figure 5. The first embodiment of the invention comprises a plasma chamber designed with a Dielectric Barrier Discharge (DBD) configuration, shown in Figure 6. This type of discharge is generated by applying high voltage to electrodes separated by a dielectric material. In the case of the plasma chamber of the first embodiment of the invention, the dielectric barrier is alumina in the shape of a tube. There are several other materials that can be used for the dielectric material, such as zirconium, quartz and borosilicate glass. The dielectric barrier prevents the plasma from becoming an arc discharge and causes it to switch on and off repeatedly (at 250 kHz), resulting in a series of micro-discharges. The plasma chamber includes a quartz window inserted in its center, allowing for optimal viewing and analysis of the plasma reactions. The quartz window is used to connect the plasma chamber to a spectrometer, though a fiber-optic cable. The first embodiment of the invention also comprises an electrical system that provides the specific electrical conditions for sustaining a stable plasma condition. The voltage (or electrical field) in the reactor must be high enough to accelerate the electrons at a sufficient speed to collide with and ionize gas molecules, initiating an electron avalanche. After this, the amount of ionized charges over time (or current) must be limited to a specific operating value depending on the gas pressure and desired plasma conditions. To achieve this, a resonating inverter stage feeding a high-voltage transformer was implemented as the preferred topology for the power supply. This circuit has the ability to increase the voltage charging the resonator when the external load is low (plasma not ionized), when the voltage is high enough to start the ionization of the biphasic fluid, the plasma is formed, and the load increases. In that scenario, the resonator gives its stored energy and the voltage lowers to a state in which the voltage-current characteristics of the plasma match the requirements. Figure 7 illustrates the different components of the energy supply system to power the plasma chamber. Besides the power source, the system consists of an AC / DC converter, inverter, and resonator, which will be explained in detail below. The AC / DC converter takes the electrical energy from the 220 V, 50 Hz power grid and converts it within an adjustable range of continuous voltage between 0-400 V. The inverter transforms the continuous voltage signal into a modified sinusoidal alternating signal with an adjustable frequency currently set to 250 kHz. The AC / DC converter sets the amplitude of the voltage. The resonator circuit serves a dual purpose. Firstly, it raises the voltage to a level capable of initiating plasma and filters the wave. The circuit comprises a resonant tank, consisting of an inductor and a capacitor, which filters the voltage wave and provides the first amplification stage. Additionally, a transformer adjusts the voltage and current levels the plasma reactor requires when it is ionized. This electrical system is critical to the operation of the DBD plasma reactor, as it enables the plasma to be initiated and maintained at the required levels. The AC / DC converter, inverter, and resonator circuit combination allows for precise plasma process control and ensures efficient and effective plasma production. The first embodiment of the invention also comprises an AS734111-Channel Spectral Sensor (VIS- NIR), which is self-contained. Additionally, only visible light fiber optics were implemented, which are simpler to handle and integrate into existing plasma chambers. The neural network processor is powered by a Kendryte Dual Core K21064-bit RISC-V SOC (System on Chip). This processor is compact and highly powerful. It is also compatible with standard pre-trained Tensorflow neural models. A successful concept prototype and several pre-series units, shown in Figure 8, were built and tested. Along with a PC data logger application, a telemetry application was developed to store data in our proprietary telemetry platform hosted in Amazon Web Services. A software application, shown in Figure 9, was developed to efficiently collect the information from the device, run experiments, store data in a spreadsheet to be used later by other analysis software, and train the neural models. The K210 module offers a variety of programming options, including Micropython —a faster, embedded version of Python— standalone bare metal C, and the use of a real-time operating system such as FREERTOS. The best approach would be to use bare metal C in combination with FREERTOS as the scheduler and operating system. This decision was made due to the complexity of the precise timings required by the SPI port, the unique trigger / exposition control signals, and the higher data rate needed. Using FREERTOS allows for the seamless use of the second core of the CPU and deterministic threads. Another reason for choosing C was related to memory management. Although the K210 has ample memory, it was necessary to use non-fragmented, aligned memory chunks for high-speed data buffers. Static buffers ensured deterministic memory usage without the risk of memory fragmentation, garbage collection, and other related issues. After configuring the development environment, the necessary spectrum module drivers (SPI and control signals) were implemented. The communication frames and signals were tested, and the correct timings were verified using a 100 MHz 16-channel signal analyzer. Initial testings The initial validation steps for the first embodiment of the invention were successfully executed, which involved testing the invention’s ability to emit and characterize different spectra based on the fluid being processed. This was done using the 10-channel low-resolution spectrum detector and different types of water. The 10-channel low-resolution spectral detector tests, as the name suggests, only has spectral channels that produce bar graphs showing the measured intensities of each channel. An application was developed using a linear combination of Gaussian approximations of the received data to reconstruct a spectrum from the raw data, based on the manufacturer’s specifications of gain and Full Width at Half Maximum (FWHM) for each channel, which was then displayed on the screen as a continuous function instead of a bar graph, as shown in Figure 10. Samples of a solution that contained 1% volatile compounds were used for the initial conceptual trials of the invention. This included acetone and other volatile organic compounds, easily detectable due to their lower boiling point compared to water. As a result, they will be present in higher concentrations during the flash evaporation process in the plasma chamber. In these experiments, distilled water was passed continuously while the system operated. Then, the feedstock was switched to contaminated water (with acetone, for example) using a valve without stopping the system. The surface graph indicated that a notable spectrum change occurred between seconds 50 and 60. Several spectral data analysis were carried out, as those shown in Figures 11, 12 and 13. Analysis Module The low-resolution spectrometer implemented in the first embodiment of the invention allowed to identify patterns in the plasma, enabling the detection of any modifications made to the liquid sample flowing through the plasma chamber. However, the spectrometer was replaced with one of higher- resolution for the specific identification and quantification of chemical species present in water. The high-resolution spectrometer was selected and integrated to provide more detailed spectral information, allowing for enhanced recognition and analysis of the chemical species. Its improved resolution offers greater accuracy in identifying and quantifying the specific components present in the sample. The first spectrum, shown in Figure 14, is a typical plasma spectrum emission taken from the water tap water was the sample used to generate these spectra where it is possible to identify, in high resolution, different elements, which are hydrogen and oxygen that come from the water dissociation caused by the high voltage between the electrodes and what sustains the plasma generation. Also, it is possible to see peaks that can be attributed to oxygen or nitrogen, which, in this case, can be gases dissolved in water. Furthermore, it is possible to observe a large band at 309 nm attributed to the OH bond or a hydroxyl radical species. In Figure 14, it is possible to see two spectral lines. The red ones correspond to a low level of power applied to the electrodes, and the other one, in orange, corresponds to a high-power level. In these tests, the increased power reduced the OH band at 309 nm, while any alteration was observed in H alpha (656.3 nm). In both spectra, the intensity is too high to be differentiated by the spectrometer. But the interesting thing here is that the signal intensity of the emissions is inversely proportional to the power applied to generate the plasma. But that is not a rule, as it was demonstrated in other tests. Figure 15 is the first attempt to measure sodium chloride dissolved in water. Using low power, there are no peaks different from those previously observed. But it is clearly observed that there is an increase in the intensity of the band at 309 nm that then decreases in intensity when the plasma power increases excessively. Its spectrum was taken from a sample of salt water with NaCl until a conductivity of 1000 µS / cm in a flow of 4 L / min. The Sodium lines were not observed, probably because the drops of the sample are large enough to prevent rapid evaporation of water, desorption of salts, and, consequently, atomization. As in the initial ones, tests with the high-resolution spectrometer were also carried out with samples containing volatiles, specifically polar organic compounds —miscible in water— easily transported to the gaseous phase within the chamber due to high velocity and low-pressure conditions inside the chamber. Due to the low-intensity lines emitted by the volatiles, a normalized logarithmic scale was used to maximize those weaker signals and obtain a better visualization. Figure 16 illustrates the spectral lines from the water (baseline in blue) and the alcohols and ketone bands attributed to the "CO" structure derived from the oxygenated functions of hydrocarbons. With the shape of these lines, it is possible to identify a pattern and differentiate samples of water that have been contaminated. The following table summarizes all peaks identified after the initial test using a 4 L / min chamber to ionize chemical species in water and identify them using a high-resolution spectrometer. Second version of the plasma chamber Concept tests conducted with the first embodiment of the invention, but using the high-resolution spectrometer, provided valuable insights. It was observed that although the desired level of atomization has not been fully achieved, the high velocity and low-pressure conditions inside the chamber in the first plasma chamber it was possible to desorb gases dissolved in the sample and identify them in the spectra. However, further technological development is required to improve the atomization process. The droplet size inside these initial plasma chambers is insufficient to ensure complete evaporation within the plasma zone, solids dissociation, and ions excitation to generate spectral lines. To fully ionize the sample and achieve the desired objectives, a new DBD chamber with an improved design was developed, as depicted in Figure 17. This chamber was specifically designed for spectrum analysis applications and operates at a working pressure of approximately 10 bar. It features a smaller size, lower flow rate, and enhanced nebulization capabilities. The plasma chamber has a volume of 1 L / min and can handle a minimum frequency of 50 kHz, with a power range of 100-250 watts. By operating at 200 kHz, the power capacity can be increased to 1 kW, which is suitable for effectively ionizing molecules and atoms. The chamber electrodes have a dielectric barrier discharge (DBD) configuration and are integrated into an aluminum oxide (Al2O3) tube with high electrical permeability. Furthermore, a semiconductor-grade quartz rod with a core diameter of 1 mm is used to efficiently couple the plasma reaction emissions to the outside, enabling comprehensive spectrum measurements. The device also includes a standard SMA fiber optic port connection with a UV-VIS FO patch, ensuring convenient connectivity for spectral analysis. Figures 17 and 18 show the DBD plasma chamber with the aforementioned characteristics. Screening test The second embodiment of the invention was subjected to a screening test, a basic procedure conducted to measure and analyze the emission signals using the high-resolution spectrometer. The performance of the DBD chamber was optimized through various tests to evaluate the impact of applied power, system pressure, and sample pH on the ionization process. These experiments allowed us to assess the influence of these parameters on the generation of spectral emissions. They provided valuable insights about the system's behavior under different operating conditions. The results of these tests were used to determine the operational limits of the chamber's flow rate, which was defined nominally as 1 L / min. With the optimized DBD chamber performance, the spectral analyzer used in this study was expected to provide an accurate analysis of samples at the defined operational parameters. The general objective of the screening test is to assess the stability of the plasma and its ionization capabilities and identify emission spectra standards under different physical and chemical conditions, as well as reagent scenarios. This evaluation pertains specifically to the non-optimized 1 LPM chamber of the second embodiment. Some of the specific objectives of the screening test are to evaluate how applying a vacuum to the chamber can stabilize the piston effect and contribute to the gain of the emission spectrum signal. An external pump will be added to turn the effect on and off, and differences will be checked. Also to check the effect on the operating pressure of the chamber within the allowed range (from 7 to 17 BAR); to evaluate the correlation between the applied plasma power, signal intensity, and ion signal generation within the allowed range; as well as to determine the ability to detect the presence of polar solvents (acetone, ethanol, and others) and molecular compounds (I2, Br2, NH4) and how this affects the performance of the invention. The background effect in the screening test was investigated by manipulating the pH of the media, ranging from acidic to neutral and alkaline conditions. An experimental plan was implemented, consisting of three sequential stages: "Screening test design: operation parameters," pH sweeping, and "proof of concept." The initial stage, "Operation parameters," provided crucial insights and guidance for the subsequent stages of the experiment. The results obtained from this stage played a significant role in shaping the experimental approach and determining the variables and parameters to be investigated in the subsequent stages. For this experimental stage parameters were optimized to improve the spectral signal gain, such as nozzle inlet pressure, power applied to the electrodes, and the use or not of an auxiliary pressure relief pump at the chamber outlet. When a water molecule enters the plasma chamber, it undergoes a process of breaking the molecular structure, generating reactive species that may or may not recombine, forming H2, H2O2, O2 and oxygenated radical species and radical hydrogen. These species generate a spectrum with very characteristic emission lines and bands that can be attributed to water. This standard spectrum consists of a baseline, the characteristic background of the spectral analysis performed on samples whose matrix is water. Because of this, it is necessary to verify how this spectrum of water behaves according to the pH of the medium as a first approach to understanding ionization in an aqueous matrix in the plasma chamber. Therefore, each experimental test must be done by measuring the emission intensities, at which wavelengths these spectral lines appear to determine discrimination between them. The emission lines of the typical water plasma spectrum and their corresponding species are shown in the following table.

[0002] Under the conditions in which the plasma chamber works with a nominal flow of 1 L / min of degassed distilled water, the spectral data of the samples will be collected for 15 seconds at each pH level (4, 7 and 10) of the water and changing the pressure and power chamber at 3 levels. The chamber line must be connected to a sampling device, which is connected to tanks with working fluid at 3 pH levels. In addition, a tank of distilled water should be used to clean the line between sample collections. Experimental test Various sodium salt solutions were prepared to test the identification of ionic species dissolved in water. Table 3 provides information on these solutions, which were prepared to have a total concentration of 1000 ppm of sodium (approximately 1417 μS / cm of conductivity). Additionally, a potassium chloride solution with a conductivity of approximately 1413 μS / cm was also used. This test had two purposes. Firstly, it aimed to assess the capability of the invention to analyze solids dissolved in water by examining different types of sodium salts. Secondly, it sought to evaluate the behavior of the plasma chamber when exposed to high concentrations of dissolved salts in water (shown in the table below). The electrical conductivity of the working fluid can give rise to several issues that can affect the proper operation of the plasma chamber. These issues include the precipitation of salts and oxides in the ceramic tube, increased plasma energy consumption, and problems with heat dissipation. In the previous embodiment, spectral lines at 309 nm were observed, which were attributed to the presence of the hydroxyl radical. The hydroxyl radical (OH·) is a highly reactive species and serves as a precursor to hydrogen peroxide (H2O2) formation. In the presence of transition metals such as iron (Fe), the formation of hydrogen peroxide can be catalyzed shortly after passing through the plasma. The experiment aims to introduce iron ions into the working solution of the second embodiment to feed the reaction chamber and analyze the resulting spectral changes. The concentration of the transition metal, in this case, iron, was set at 0.5 ppm (parts per million). By introducing iron ions into the working solution and subjecting it to the plasma in the second version of the chamber, the goal was to observe if the presence of iron can lead to changes in the spectral lines of water, which serve as the spectral background in this case. These changes in the baseline caused by catalytic reactions in the plasma reaction medium could potentially generate erroneous spectral data due to iron interference. By understanding the effects of iron interference, adjustments can be made to minimize or compensate for any spectral distortions, leading to improved analytical results and the reliable detection of target species in water samples. The typical emission lines that appear when the plasma works come from the gas phase inside the chamber, which could be the gas dissolved in water, probably: oxygen gas, nitrogen gas, or carbon dioxide. In addition, some spectral lines could be assigned to water gas. New spectral lines could appear in the observed spectrum if very volatile chemical compounds were added to the water. For example: Gas halogens (Cl2, I2, , Br2): the solubility of iodine in water is indeed influenced by temperature (typically 20°C) and pressure (usually 1 bar), which is relatively low. However, iodine exhibits better solubility in iodine solutions. In the presence of iodide ions (I-), the following reaction mechanism occurs I2 + I- → [I3]-. In the second embodiment, which operates using the piston effect, iodine tends to move into the gas phase within the plasma chamber, escaping from the water as iodine gas. Under these circumstances, it is reasonable to assume that iodine gas and other halogens like chlorine and bromine can potentially interact with the plasma. Consequently, the typical spectrum observed in the second embodiment can be modified by the presence of these halogen gases, generating new emission lines within the conventional water spectrum. Ammonia, a compound of nitrogen and hydrogen (NH3), is a valuable substance for conducting tests with the second embodiment. With its distinct chemical properties and characteristics, ammonia offers insights into the capabilities and performance of the invention. When introduced into the second version of the chamber, ammonia interacts with the plasma and other reactive species within the system. These interactions can form new compounds and emission signatures, influencing the overall spectral profile observed during the experiments. The use of ammonia as a testing agent in the second embodiment enables the examination of various aspects. Firstly, it allows for assessing the system's ability to handle and process different gas compositions, particularly those containing nitrogen and hydrogen elements. Monitoring the emission spectra and analyzing the resulting data, can gain insights into the chemical transformations occurring within the chamber, including the dissociation, ionization, and recombination processes involved in ammonia processing. Polar Solvents (Alcohols and ketones), such as methanol, ethanol, and isopropanol were tested as organic compounds that are very soluble in water and very volatile. Also, Acetone will be tested as a representative of the polar group. It hopes that introducing organic groups containing OH functions will change the typical emission spectrum of water when passing through the plasma and undergo oxidation reactions, capturing OH radicals and forming aldehydes or carboxylic acids. The tests will be subjected to a concentration of 1% v / v of this polar volatiles and gradually increased for safety. Use cases tests The second embodiment of the invention was tested in a specific use case to identify samples contaminated with volatile organic compounds (VOCs). VOCs are chemicals that can vaporize in the air and dissolve in water. They are widely present in various aspects of daily life, including industrial processes, agricultural practices, transportation, and common household activities. It is crucial to detect and monitor VOC contamination, as once released into groundwater, many VOCs can persist and migrate to drinking water sources. One particular class of VOCs of concern is the water-soluble fraction of gasoline (WSFG) compounds and additives. These compounds are occasionally detected in groundwater, often from leaking underground gasoline storage tanks. Despite being invisible, these storage tanks are a common source of gasoline VOCs that can contaminate groundwater. To prepare the Water-Soluble Fractions (WSFG), the procedure outlined by Afolabi et al. (1985) was followed. In this process, 500 cm3 of gasoline was combined with 1500 cm3 of distilled water, and the mixture was stirred using a magnetic stirrer for 24 hours at room temperature. After the 24-hour agitation period, the mixture was allowed to settle for a minimum of 3 hours to obtain a clear interphase, separating the WSFG from the rest of the solution. The design for optimizing the chamber's operating parameters includes varying the pressure applied at the chamber inlet (at 7, 10, and 17 bar); and adjusting the power applied to the electrodes, as is described in Table 1 of Annex 2. Additionally, a relief pump was used to generate pressure relief on the outlet of the plasma chamber. The second pump only operated in an on / off manner, and the test was performed separately following the mode of operation of the second pump. The power applied to the electrodes was adjusted based on the selected potential in the power source, varying between 14, 75, and 150 volts. As stated before, the tests were separated into two groups according to the use of the relief pump. The first group of data was obtained with the pump turned on, and for each input pressure of the chamber, a certain power was applied according to the potential selected on the power source. Therefore, the second group includes tests where the pump was turned off. Since the dielectric barrier chamber experiences a different capacitance for each configuration of the input pressure, which not only depends on the physical characteristics of the chamber but also the degree of atomization of the sample within the chamber, the final current passing through the electrodes will always be different. As a result, the applied power in watts will also vary. First test group: relief pump on The spray within the cylindrical plasma chamber should achieve the smallest droplet size to maximize the wet surface area between the liquid and gaseous phases of the stream in the active zone. The relief pump is expected to enhance the piston effect of the nozzle, making it easier to atomize the sample and increasing the presence of gaseous phases. A typical spectrum was observed in Figure 19 for the water at 7 bar, indicating broadband from OH at 309 nm, as well as the H ^^ lines at 656.5 nm which correspond to the 3 -> 2 transition from the Balmer series. Additionally, the 4 -> 2 transitions represented by the symbol H ^^ can be observed. The lines from O atoms can be seen at 777 and 845 nm. An increase in intensity in the spectral baseline is observed across the entire spectral range of 29 W (in red lines), particularly between 600 and 800 nm. These emissions correspond to the visible light range, specifically in the red and near- infrared regions. This can be due to the low power intensity applied to generate the plasma, ambient light may interfere with the baseline. Also, at lower applied power, the spectrum obtained from the plasma chamber has a much noisier spectral baseline, presenting multiple peaks between 309 and 400 nm. The spectrum obtained from water usually presents a characteristic emission at 309 nm attributed to the molecular bond of OH. At 7 bar and with only 29 watts, which generally presents as a single peak, a doublet can be observed at 309 nm and 315.5 nm. Both lines can be attributed to oxygen. Other lines at 336.5nm, 357.5 nm, and the small doublet at 380 nm are other possible transitions that can also be attributed to oxygen atoms. Even at 7 bar of pressure, as the applied power to the chamber increases, the hydrogen and oxygen emissions lines mentioned earlier become more well-defined and intense, particularly the emissions corresponding to alpha hydrogen and the emission attributed to OH. As well, if we maintain the power applied to the chamber constant and increase the pressure in the nozzle, what is observed is that the signal-to-noise ratio decreases, and this can be observed more clearly when the chamber is operating at very low power, as in the example of 29 W. Figures 20 and 21 present experimental data obtained at 12 and 17 bar, respectively, which exhibit striking visual similarities to the data obtained at 7 bar. However, one notable distinction is observed in the case of 29 W at 12 and 17 bar, where the presence of line noise is reduced, and the peaks associated with oxygen exhibit decreased intensity. Moreover, it is worth mentioning that beyond 245 W, there was no substantial augmentation in spectral information. Instead, the heightened power merely intensified the preexisting peaks. Principal Components Analysis of the dataset from the second embodiment testing To conduct a more in-depth study of how the operating parameters influence the spectral generation of the second embodiment, a statistical analysis of the data was carried out using the multivariate analysis tool Principal Component Analysis (PCA). PCA is a statistical technique used to analyze and reduce the dimensionality of a data set while preserving its important features. PCA aims to identify patterns and relationships within the spectral data that can be attributed to the variation of a given physical quantity. In this context, we relate to the plasma power and the inlet pressure. The resulting principal components are ranked based on their contribution to the overall variation in the data by examining the Loads and Scores of these components. In summary, Loadings represent the contributions of the original variables to the principal components. At the same time, scores indicate the positions of samples in the reduced-dimensional space defined by the principal components. Together, loadings and scores provide valuable insights into the spectral patterns and relationships within the dataset. A data matrix measuring 9 by 1321 was constructed for the PCA analysis using spectral test values. Each matrix’s row contains 9 samples from a particular pressure and power spectral condition. In contrast, each column contains the average intensity signal values from all wavelengths between 190 and 850 nm. Figure 22 shows the scattering of PCA scores. Together, PC1 and PC2 capture 94.2% of the variation in the data. Thus, a two-PC model for the four test variables seems reasonable. The differences and separations between the samples observed in the PCA graph are very similar to what is seen in the spectra of each sample. For example, the 29 W spectra at 12 and 17 bar, respectively. The symmetry observed in the new PCA plane is due to the extremely correlated nature of all wavelength variables. This differentiation makes it possible to distinguish between one sample and another in terms of emission intensity. The Information seen in Figure 23 about PCA Loading brings information about the weights assigned to each original spectral variable in the principal components. They indicate the contribution of each variable to the principal components and provide insight into the correlation between the original variables and the principal components. High loading values indicate a particular variable's strong influence or importance on the corresponding principal component. Based on this information, when analyzing the PCA graph, for the PC1 scoring axis, the variables with the highest weight are normally conserved in a water spectrum, such as the alpha hydrogen emission at 656.5 nm, the OH broadband at 309 nm and the two oxygens at 777 and 845 nm. The PC2 axis discriminates samples based on observed emissions between 335 and 356 nm, also attributed to oxygen. Also, a spectral analysis study of the samples using the statistical treatment of Hotelling T² and the residual Q chart was used to analyze the obtained data. The statistical treatment of Hotelling T² enabled the analysis of the relationship between multiple spectral variables, determining if there was any significant relationship between them. On the other hand, the residual Q chart was used to identify anomalous observations in the spectral data, allowing for identifying and eliminating data irrelevant to the study. The control limits in a Hotelling T² analysis, and the residual Q chart have different meanings. The control limits in a Hotelling T² analysis and the residual Q chart shown in Figure 24 have different meanings. In this study stage, where we only wish to compare the effect of pressure on the nozzle at different powers, the control limits were T²=19.028. This limit represents the region where the means of the samples of a multivariate dataset are considered statistically normal or acceptable. Any point outside this region indicates a significant difference between the sample means, which may indicate a problem in the process that produced the data or an anomaly in the data itself. For this experiment, all samples, even when subjected to different pressures and powers, exhibited the same spectral profile (all had the same emission lines typically observed in a water sample, which makes sense since all samples were distilled water). Regarding the limit value of Q = 48.19, we can see how much one spectrum differs from another when subject to different conditions. The first spectrum obtained at 29 W and 7 bar had the highest Q score (856.9), followed by the condition of 490 W and 17 bar (122.15). This indicates that under these conditions, something anomaly is causing a significant disturbance, which should be further investigated. However, it is worth noting that to generate sequential spectra of the same type of sample, the pressure, and power applied to the plasma must be strictly controlled in the future, as such disturbances can cause significant distortions if the purpose is to quantify the substance present in the sample. The PCA analysis reveals a linear relationship between the spectral emissions of each sample and the plasma power when the pressure remains constant. This linearity is consistent even when varying the pressure at the chamber nozzle. Certain conditions exhibited similar spectral characteristics. For instance, at 29 W, the spectra obtained at 12 and 17 bar showed a close grouping and a similar grouping was observed for the condition at 7 bar when using power levels of 245 W and 490 W. In summary, pressure or plasma power variations, particularly when utilizing a relief pump as a pressure reliever at the chamber outlet, result in statistically distinguishable spectral responses. Second test group: relief pump off It should be noted that these tests were carried out on the same day with random sequencing between the tests, and were treated separately for data treatment simplification and better clarity. All the tests carried out to obtain the spectral pressure of 7 bar were considered unsuccessful due to unstable plasma behavior or simply the inability to generate it. Therefore, the data reported only refer to the tests carried out at pressures of 12 and 17 bar, as shown in Figures 25 and 26. Without a relief pump at the plasma chamber outlet, generating plasma at 12 bar and 17 bar pressures is feasible. At low power levels, around 25 W, the spectral emissions exhibit additional peaks near 309 nm, similar to the previous session. However, the spectral baseline tends to increase in these cases. Various factors can contribute to baseline elevation in an emission spectrum, including electronic noise, contamination, ambient light, temperature, and energy source intensity. With lower plasma power, the weak signal intensity from the species ionized by the plasma is susceptible to interference from ambient light, leading to baseline distortion. As the applied power increases, the intensity of the emission signal rises, causing a decrease in ambient light interference. Conversely, when the power exceeds 600 W, an elevation of the baseline is observed, forming a broad band between 560 and 640 nm. This phenomenon can be attributed to an increased system temperature, which is not observed when the relief pump is activated. Ionics compounds dissolved in water The tests carried out using the 1 L / min chamber, the second embodiment, presented below are similar to those carried out with the 4 L / min chamber. An attempt was also made to ionize a sample containing salts dissolved in water, as is possibly seen in Figures 27 and 28. Potassium and sodium chloride were used in this test at 1413 µS / cm (conductivity) and 1000 ppm (TDS), respectively. The first tested was potassium because this element presents an intense and characteristic emission line as a doublet at 765.5 nm and 770 nm. In addition, the ionization potential of potassium is lower (4.3407 eV) than sodium's (5.1391 eV). Therefore, it is easier to obtain a spectrum with the characteristic emission mentioned above. Unfortunately, detecting any components within the power scanner ranging from 60 W to 150 W was impossible. The emission lines of salts such as potassium or sodium were not observable, likely due to incomplete evaporation of the droplets caused by the plasma present in the chamber, meaning that the process of separating the salt from the droplets did not occur. Consequently, the salts were not dissociated, and the elements were not excited to their highest energy state. Interaction with Iron Like the previous test conducted with sodium and potassium, water samples containing iron at a concentration of 0.5 ppm were subjected to analysis using the second embodiment. However, no peaks from iron were observed in the continuous spectrum. Taking advantage of the experimental opportunity, we conducted a power scan up to 150 W to investigate any distinctive response from the emission band at 309 nm, which is typically associated with the generation of hydroxyl radicals. Hydroxyl radicals generate peroxide in water when a stream of water passes through the plasma. The interaction of iron ions with hydroxyl and peroxide radicals was expected to result in some form of spectral alteration. However, as depicted in Figure 29, no spectral changes were observed. Results Spectral emissions from volatile compounds After conducting initial tests to identify dissolved cations in water, the experimental investigations tested low molecular weight compounds that the piston effect could easily volatilize. Tests were conducted with ammonia and saturated solutions containing halogen gases such as chlorine, bromine, and iodine. Subsequently, tests were performed on water contaminated with fuel, specifically gasoline, and polar organic solvents, including ethanol, isopropyl alcohol, and ketones. Ammonium: surprisingly, as shown in Figure 30, no spectral lines attributed to the nitrogen atom were observed. It was expected to observe spectral emission peaks at wavelengths such as 228.5 nm, 336.7 nm, 399.5 nm, and within the range of 500 nm to 600 nm. However, none of these expected spectral features were detected. Chlorine gas: given its instability, it was anticipated that when analyzing an acidified sample of sodium hypochlorite, the gas would transition to the gaseous phase due to the piston effect of the chamber. Consequently, the chlorine molecule would be exposed to the plasma during the analysis. Chlorine gas can indeed be readily generated from an acidified sodium hypochlorite solution. It should be noted that this solution can be unstable if not stored properly. Based on this understanding, it was expected that during the analysis of an acidified sample of sodium hypochlorite, the gas would transition to the gaseous phase due to the piston effect of the chamber, thus exposing the chlorine molecule to the plasma. Strong emission lines were anticipated to appear between 475 - 545 nm and 800 - 850 nm wavelengths. However, contrary to expectations, no changes were observed in the water spectrum, as depicted in Figure 31. Bromine: molecular bromine is known to be relatively unstable in an aqueous solution and can be quickly displaced from the aqueous phase in the form of gas when the solution is disturbed. In the plasma chamber of the invention, the piston effect's rapid phase change could displace the gas bromine to the chamber gas phase and expose the molecule to the plasma. Strong emission lines were expected to appear within the 435 - 850 nm range. However, an emission line was observed specifically at 804 nm, as depicted in Figure 32. This emission line originated from bromine atoms excited by the plasma at a power of 66 W. Interestingly, this visualization was only possible at low power levels. As the power applied to the chamber was increased, the emission line gradually weakened and nearly disappeared at 150 W. It is speculated that the reaction of bromine gas with other species at high power levels may hinder the spectral emission observed previously. The exact cause or mechanism behind this phenomenon has not yet been determined. Following the example of some experimental observations made for OH molecular emission lines, increasing the potency for the iodine case leads to the opposite effect of what would be expected when increasing the potency. Most likely, the species as such, capable of emitting a specific wavelength when leaving its ground state for an excited state, is quickly consumed by the reactions present in the plasma. This leads us to hypothesize that an adequate power level is required to detect certain components. In other words, each molecular or atomic emission needs discrete amounts of energy to excite, and these discrete energies can be achieved by adjusting the plasma power. Iodine: similar to the previous tests conducted with halogens, it was anticipated to observe spectral emissions from iodine within the wavelength ranges of 255 nm to 390 nm, 530 nm to 620 nm, and 800 nm to 840 nm. Regrettably, no emission lines attributed to iodine were identified in the water spectrum during the analysis, as seen in Figure 33. Gasoline water-soluble Fraction (WSFG): the ability to detect volatile species using the second embodiment of the invention led to an experiment involving the preparation of WSFG to simulate gasoline contamination at a laboratory scale. In this experiment, gasoline and distilled water were mixed in a ratio of 1:3 and left in direct contact for 24 hours. Afterward, the aqueous phase was separated and stored in a dark container at 4 °C for future use, with a maximum storage duration of 5 days. It should be noted that the water-soluble fraction of gasoline refers to the additives used to enhance the octane rating of gasoline, which can include alcohols such as methanol or ethanol, as well as other additives like surfactants that aid in the mixture of these substances. Also, trace amounts of polycyclic aromatic compounds, such as polyphenols, may be present in this water-soluble gasoline phase. Figure 34 displays the spectrum obtained from this sample, which was subjected to ionization at power levels of 70 W and 150 W. Within the wavelength range of 400 nm to 650 nm, carbon bands attributed to CO bonds can be identified. Once again, increasing the power leads to a decrease in the emission signal intensity from these volatile compounds. Polar Organic Solvents in water The following results pertain to tests conducted with acetone and various alcohols dissolved in water. A separate spectrum was obtained for each type of solvent to allow for subsequent comparison. Similar to the observations in the previous test with the WSFG sample, the typical emissions observed for these solvents fall within the 430 nm to 605 nm range. Ethanol: to observe the spectral lines of ethanol, shown in Figure 35, it was necessary to increase the concentration to 5%. At a concentration of 1%, the emissions were too weak to be identified and distinguished from the baseline. Additionally, it was crucial to maintain the power applied to the plasma at a high level to enhance the intensity of the spectral emissions. Isopropyl: the spectral analysis of a water sample containing isopropyl alcohol proved more challenging than the ones conducted with ethanol. This was primarily due to the low intensity of signals obtained from a 1% and a 5% solution. Additionally, it was necessary to adjust the power at various levels to obtain a satisfactory spectral signal. In the case of isopropyl alcohol, as seen in Figure 36, a power level of 125 W was determined to be suitable for achieving a discernible spectral signal in a 5% solution. Acetone: among the volatile substances analyzed thus far, the acetone sample proved to be the least complex. Like the previous samples, emissions attributed to the oxygenated organic function were only identifiable at concentrations above 5%, as shown in Figure 37. However, the spectral emissions from acetone were easily visible with a plasma power applied at or above 74 W. Principal Component Analysis (PCA) on spectral data from proof-of-concept tests The PCA analysis on the proof-of-concept spectral dataset, shown in Figure 38, exhibits a significant distinction within the PCA model, effectively discriminating between samples containing dissolved volatile substances and those containing added ionic compounds. This underscores the applicability of the PCA tool for data preprocessing to study the phenomena occurring in the plasma chamber that give rise to spectral information. Notably, all samples subjected to high power (primarily around 150 W) tend to cluster in the second and fourth quadrants of the PCA plane. Conversely, samples containing alcohols and ketones are predominantly located in the upper quadrants, particularly the second quadrant, forming a distinct cluster separate from samples containing sodium or potassium, iron, and ammonium salts. Interestingly, despite being unstable in aqueous media, halogen compounds align with dissolved salts in the same group. However, only the samples subjected to high power can be distinguished from the others. Furthermore, as shown in Figure 39, the PC 3 axis displays an inverse correlation with the variable at 309 nm and the one at 777.2 nm, while PC 2 demonstrates a direct correlation with the variable at 656 nm. Based on these findings, it can be inferred that the discrimination among volatile compounds, alcohols, and acetone groups is likely attributed to differences in the shape and intensity of emissions such as H alpha and OH. The second embodiment plasma chamber of the invention has proven to be a significant advancement in spectroscopy. Its ability to achieve a stable plasma has allowed for proper spectral characterization with a high-resolution spectrometer. However, it is crucial to note that the emission lines of salts such as sodium and potassium cannot be observed due to incomplete evaporation of droplets. Therefore, subsequent development shall promote the complete atomization of chemical species to expose them to the plasma. Moreover, the measurement capabilities of the method and apparatus of the invention have demonstrated that each species is detectable within a specific power range, emphasizing the importance of precise and accurate power control. The second embodiment of the invention has also allowed the identification of low concentrations of volatile species, essential in fields such as environmental monitoring and analytical chemistry. Overall, it provided relevant information for the subsequent development steps, towards the goal of providing a reliable tool for real time water quality monitoring. Tests with an ultrasonic nebulizer The first embodiment of the invention, which had a plasma chamber with a flow rate of 4 L / min, was adapted for the plasma tests described below. Instead of the initial nebulization approach based on pressurization and acceleration through a nozzle, a new approach was implemented using an ultrasonic nozzle, with a vibration frequency of 40 kHz. A custom-designed interface piece was created to connect the commercial nebulizer to the chamber inlet. This modified setup is the third embodiment of the invention. The initial experimentation with the third embodiment presented several challenges. The chamber experienced overheating in one of the electrodes during first spectral analyses using water as the sample. Consequently, the resin surrounding the electrodes —electrical insulation— broke. To prevent recurrence of this incident, the series of tests described below were conducted with the repaired chamber taking a series of procedural precautions. Tests were conducted using a dielectric barrier discharge chamber equipped with a 40 kHz ultrasonic nozzle, as depicted in Figure 40, to investigate the nebulization of samples containing ionic compounds. Spectral data acquisition was performed using a high-resolution UV-VIS spectrometer covering the 190 - 850 nm range. The resulting plasma's emission lines were recorded using quartz windows and optical fiber to minimize attenuation. The ultrasonic nozzle connected at the inlet of the plasma chamber, depicted in Figure 41, operates at a frequency of 40 kHz and is controlled by a power generator with an operational interface, as shown in Figure 42. This interface allows the operator to adjust the power of the nozzle attached to the plasma chamber. A schematic diagram illustrating the configuration of the third embodiment of the invention, for the experimental tests, is shown in Figure 43. In addition to the ultrasonic nozzle, a vacuum pump was connected to the plasma chamber. However, before the chamber and the vacuum pump, a set of components was implemented to perform two functions: cooling the non-vaporized sample and separating the superheated vapors exiting the chamber before being evacuated. The liquid portion is directly evacuated to the exterior by a pump, for instance, a peristaltic pump, while the gases pass through a vapor trap to the vacuum pump. The third embodiment of the invention was subjected to a testing program using solutions containing different concentrations of potassium chloride, sodium chloride, ferric chloride, zinc chloride, calcium chloride, and magnesium sulfate were prepared. The plasma chamber was operated under high vacuum conditions, and the sample flow was minimized to generate an aerosol spray inside the plasma chamber. Before initiating the plasma, the aerosol sample was introduced into the chamber for a specific duration (60 s), and its behavior was observed at the chamber outlet. Subsequently, the plasma was ignited for 5 seconds to collect spectral data, after which it was turned off while maintaining the sample feed to the chamber. These experimental parameters were employed to accommodate the limited heat dissipation capacity of the chamber. The objective of this experimental procedure was to achieve improved nebulization compared to the 1 L / min setup, resulting in a significant reduction in droplet size and the formation of an aerosol that could be efficiently vaporized upon reaching the plasma zone. This would enhance the atomization process of the sample compounds, leading to the generation of characteristic spectral emissions corresponding to the species present in the sample. Tests of the third embodiment of the invention As a preliminary analysis of the results obtained from the tests conducted on the third embodiment, the table below summarizes the experimental data obtained from the oscilloscope and the control instruments of the power source and inverter board. As observed experimentally, there were several instances where the plasma could not be initiated, or if plasma was obtained, it was sustained for an insufficient amount of time to perform readings on the oscilloscope. These plasma instabilities were observed for samples containing iron, calcium, zinc, and sodium ions. In some cases, samples containing magnesium ions also exhibited similar behavior. Regarding data analysis, the recorded spectral samples were stored as timed sequences (CSV files). These files underwent manual trimming to remove irrelevant data and zero plasma conditions, resulting in clean files containing only the spectrum data of the various plasma reactions. The software OCTAVE was used as a numerical tool to import the CSV files into memory, plot the data, and perform analysis. A set of programs was developed to load each spectrum "CSV" file from a directory and store them in separate memory variables to automate the process. Another program was created to consolidate all the data into a single structure, including extended data and range names, enabling proper comparisons between the different datasets. An example of the execution output from the program and the range definition structure can be seen in Figure 44. Additional programs were designed to read the consolidated data and range information and plot them in a consolidated 2D graph, as illustrated in Figure 45. The initial analysis of the spectral data for water revealed significant differences between the spectrum generated by ultrasonic nebulization and the spectrum generated by the continuous flow of tap water at 1 L / min in the previous setup, here named by non-nebulized. Specifically, the relationship between the intensities of the H-Alpha and OH emission bands underwent considerable changes between the two systems, as seen in Figure 46. These results emphasize the influence of nebulization on the relative intensities of the H-Alpha and OH emission lines. The observed variations in the intensity ratios provide valuable insights into the different excitation and emission processes occurring in the plasma, highlighting the role of nebulization techniques in shaping the spectral characteristics of the emitted light. The spectrum analyzer used has a resolution of 0.5 nm, so the spectrum lines obtained from it will be quantized at that magnitude, so the observed maximums expressed in this document will follow this quantization (e.g., H-Alpha is at ~656.3 nm, but the instrument detects it at 656.5 nm). Also, all the intensity measurements are relative to the instrument's internal ADC reference and not to an absolute light intensity value (per unit measurement). From the samples, the higher concentration sample from each solution was selected for the detection of emission lines that could correspond to molecular or atomic emission different from the blank case (water). Figure 47 to Figure 52 display the spectra obtained from the analysis conducted using the third embodiment for each sample containing metal ions that could generate a stable plasma, used in both previous testing sets (first and second embodiment). Among the graphs shown, the only noticeable difference in terms of additional emission lines or bands was observed in the cleaning water sample, where it is likely that oxygen or nitrogen gas emissions were measured. For all spectra obtained using dissolved ions, the only differences observed were in amplitude, delivered power, and the relative intensity of the existing emission bands. No additional emission bands were detected, as expected for different elements. This can also be confirmed by examining the "delta" signal, where all the peaks are present in both signals, albeit with varying intensities. Based on the aforementioned observations from the series of experiments conducted with the third embodiment, the following conclusions can be drawn: • The overall level of background illumination contamination was significantly higher than the reference tests (approximately 675 vs.76 in the 1 LPM non-nebulized chamber). This contamination was present without plasma, indicating a potential light leakage inside the chamber. • The intensity of light emission measured in these tests was weaker than in the previous version of the plasma chamber (1 L / min) non-nebulized tests. This could be attributed to poor light coupling (e.g., fiber optics, quartz rods) or lower power emission. Combined with the increased background noise, this resulted in a significantly reduced signal-to-noise ratio (SNR). • Blank tests using tap water with dissolved gases were conducted, but it is suggested to use degassed deionized water instead. The presence of unknown salts in the blank tests may have affected the identification of faint emission lines. This effect was also observed when comparing tap water samples from different sources. • A small heat source was possibly detected at a maximum wavelength of 694 nm. Using Wein's displacement law, its estimated temperature is approximately 4175 K. This phenomenon, several times fainter than in the 1 LPM non-nebulized cases, may have been present but unnoticed before. It can be observed roughly in the 680 to 750 nm wavelength range. According with the hypothesis, the OH reaction appeared to be enhanced by improved atomization, resulting in a larger contact surface. This observation was supported by the H / OH intensity ratios, where the chamber with poor atomization at 1 L / min exhibited a ratio of 2.087, while the atomized chamber showed a minimum ratio of 0.674. This indicates that the intensity of the OH reaction increased by approximately three times compared to the H-Alpha line. Promoting the OH reaction through effective atomization highlights the importance of nebulization for proper sample atomization, which is crucial for generating emission lines from metal ionization. However, under the conditions of the third embodiment —including nebulization, pressure, steam percentage, power level, plasma regime, etc.— it was impossible to detect emission lines or bands from different reagents added into the water. The following embodiments require better nebulization. Also, for the next experiments, reagents will be added in the highest concentrations possible (approaching saturation in cold water). This approach will provide valuable insights into the detectability of these ions under such conditions. Moreover, it is essential to address the dissipation of heat generated within the chamber to advance the development of a chamber capable of ionizing the samples. Therefore, replacing the current dielectric coating with a specialized cooling system that is both dielectric and capable of maintaining the chamber within a specific temperature range is necessary. Fourth embodiment of the invention with improved nebulization The following experiments are aimed to test the hypothesis that generating smaller droplets through ultrasonic nebulization, in the third embodiment of the invention, can facilitate the desolvation and atomization of chemical compounds dissolved in water, allowing visualization of their spectral data, specially for obtaining spectral lines of metal ions. To investigate the validity of this hypothesis, it was implemented at the inlet of the plasma chamber a piezoelectric transducer operating, with a vibration frequency of 110 kHz. To ensure optimal performance, a needle valve was incorporated at the entrance to the nebulization chamber, allowing for precise adjustment of the flow rate. A 0.5 mL / min flow rate was selected as it exhibited better stability over time. Samples containing potassium, sodium, magnesium, calcium, zinc, and iron chlorides in non-acidified aqueous solutions were analyzed to verify spectral characteristics. The plasma chamber of the fourth embodiment, shown in Figure 53, consists of two concentric tubes. The outer tube has a structural function, it is made of a material such as polycarbonate, and contains a dielectric coolant liquid; while the inner tube is made of a dielectric material with a good electric permeability, such as alumina, coated with a conductive material, such as brass, in the central section, forming the electrodes. There is a defined space between the electrodes where the optical interface for the spectral analysis module is located. The optical interface can transmit the light emitted by the internal plasma reaction with minimal attenuation and distortion. This is achieved by using high-quality quartz rods that have excellent light transmission characteristics across a wide spectrum (UV - VIS - NIR), for example. The light is then channeled, for instance, through a wide-spectrum optical fiber cable, to a spectrometer. The dielectric cooling liquid enters the chamber from the top, specifically at the rear part connected to the piezoelectric nebulizer, and exits from the bottom. A pump directs it to a heat exchanger. The chamber of the fourth embodiment, shown in Figure 54, also has connectors for the high-voltage electrical cables, as well as connectors for the piezoelectric nebulizer. In this example, the inner tube coated with brass can be observed through the outer tube, made of polycarbonate. The diagram of Figure 55 depicts the main components of the fourth embodiment, linked together as a series of subsystems: • Subsystem 1: Nebulizer, sample inlet • Subsystem 2: Cooling circuit • Subsystem 3: Chamber Core, Spectral Sensor and Electrical power supply • Subsystem 4: Condenser and phase separation • Subsystem 5: Vacuum pump • Subsystem 6: Drainage The fourth embodiment relies on several interconnected subsystems to achieve the generation of plasma with the necessary conditions for ionizing and atomizing the substances within the analyzed sample. Once the sample has been properly nebulized, it enters the plasma zone, where the physicochemical processes occur, enabling the capture of spectral information. Subsystem 3, encompassing the spectral and electrical components, has undergone successive refinements across the previous three embodiments. After the plasma zone, the plasma's highly heated vapors and byproducts are directed toward subsystem 4 for condensation and phases separation before being conveyed to the vacuum pump. Subsystems 4 and 5 have essential roles, particularly in safeguarding the integrity of the vacuum pump. The plasma effluent undergoes a three-stage process: initially, it goes through a phase separator device, for instance, a 20 cm stainless steel tube with a 1 / 2" diameter, serving as a heat exchanger for superheated gases, as well as heated liquids and vapors. The liquid phase then can undergo, for example, gravity-based separation, using, for instance, a polycarbonate tube, acting as a phase separator and being pumped out of the system. The detection performance of non-volatile compounds depends not only on the intensity of the plasma but also on the level of atomization of droplets, salts, and other non-volatile compounds. Substances dissolved in a droplet do not get ionized. The continuous sample must be volatilized to detect them, and the ions must be desorbed to produce atoms and ions in the gas phase (atomization). However, regardless of the efficiency of the nebulization process, it is necessary to control the amount of sample that enters the chamber, with a regulation device; for instance, a needle valve that can control the flow of the sample. The amount of sample can then be controlled by this device. In the case of the tests described below, a needle valve was set to deliver less than 500 mg / min of the sample. The nebulization chamber, as seen in Figure 56, consists of a core comprising a piezoelectric ceramic with a mesh in the center of the plate. The plate has an ultra-fine mesh (5 µm pore size), as shown in Figure 57. The plasma chamber also includes a reservoir where the sample is held, and a driving circuit. In the reservoir, the sample is absorbed by a cotton filament that is in direct contact with the center of the piezoelectric element. The piezoelectric element vibrates at a frequency of 110 kHz, generating aerosols within the plasma chamber. Figure 58 shows the nebulization chamber housing the piezoelectric transducer with the wires connecting to the control board. The piezoelectric plate used for the implementation and testing of the fourth embodiment was sealed by a Viton O-ring and mounted on a stainless-steel plate with a central 1 / 4” orifice. This interface connects to the sample inlet to the plasma chamber. Fourth embodiment testing The initial step of the experiment involved generating a spectral baseline using degassed bidistilled water, which will serve as a blank reference. To accomplish this, a power screening process is conducted across the entire power plasma range, starting from the minimum power required to initiate the plasma and gradually increasing up to 400 Volts using the AC / DC power supply. Before discharges start inside the chamber, the cooling system must be operative, it is necessary to check the pump operation and the radiator system to cool the oil in contact with the chamber's wall. Sample solutions consisting of common metal salts, which can be readily identified using traditional spectroscopic emission techniques, are prepared for the test. With a flow rate ≤ 0.5 mL / min, it is possible to get a stable nebulization even though a high drop of sample collapse from the top tube at uneven intervals. With the needle valve adjusted at 0.5 mL / min, the next step was to run a trial test to generate plasma. The pressure inside the system varies depending on how long the plasma has been on. This means that the heat generated by the plasma and accumulated in the system generates a pressure increase. This pressure increase may occur by the complete evaporation of the sample, not only of the solvent, in this case, the water, but also of the dissolved substances in it. The initial absolute pressure inside the chamber reached 22.3 mbar (99.7 kPa gauge pressure). The pressure inside the plasma chamber exhibited significant fluctuations during the tests, so pressure measurements were recorded during spectral acquisition. Initially, the gauge pressure was approximately 99.0 kPa when the plasma was just initiated. However, as the system warmed up, the gauge pressure dropped to around 97 kPa. The chamber operated smoothly at 50 watts for a few seconds. However, disturbances were observed on the oscilloscope, causing temporary current increases and voltage drops until the signals returned to their initial forms. This disturbance occurred three more times, and the plasma automatically turned off in the last instance. Examination of the inverter board revealed that one of the SiCFET semiconductors was not receiving the trigger signal. To diagnose and resolve the issue, further investigation was required to determine whether the problem lay with the SiCFET itself or the driver circuit. The damaged components were replaced accordingly. Additionally, modifications were made to the transformer's turn ratio to achieve a more robust operation of the system, taking into account the chamber's unique impedance characteristics. A typical spectral from the water was observed using KCl solutions at 1 ppm and 50 ppm, which means broadband from OH (309 nm) and line spectra from H (656.5 nm H ^^) and O (777 and 845 nm). The H ^^ lines in 656.5 nm fit with the transition 3 -> 2 from the Balmer Series. In some flow rate conditions also, it is possible to observe the transition 4 -> 2 represented by the symbol H ^^. So, when 100 ppm of KCl was used, and a power of 2.06 kW was applied to the chamber, there was a change in the spectrum pattern observed so far. The absolute pressure of the system dropped to 4.73 kPa (47.3 mBar), and the OH band at 309 nm decreased and, for a few seconds, disappeared completely. Other peaks in the spectrum appeared, as a doublet form between 764-772 nm, as can be seen in Figure 59. As the plasma power increases, the tendency is that the OH band loses strength as the potassium spectral lines gain strength. Above 80 W the potassium lines are so intense that even H ^^ ceases to be predominant, as shown in Figure 60. NaCl samples with concentrations below 100 ppm were not used in this experiment, it is assumed that, similar to KCl, no spectrum information is generated below this concentration. No new spectrum lines were observed to 100 ppm of NaCl at 50 W Plasma Power, just the four typical lines from the water. Increasing the power to 90 W, a new spectral band appears in the 589.5 nm, corresponding to the Sodium atom, as shown in Figure 61 and Figure 62. With sodium and potassium solution samples, it was possible to excite the atoms at the lowest excited state by applying just 100 W power plasma. However, for calcium and magnesium samples it is necessary to apply more power than what is possible with this implementation of the fourth embodiment, to achieve the excitation state because the energy level to excite one electron to the lowest energy state are higher than sodium. Nevertheless, the tests with Ca and Mg were very important in testing the stability of plasma. When more energy is requested from the energy source to sustain the plasma and ionize the dissolved species, a greater oscillation in the intensities of the atomic emissions is observed in the spectrum and pulsations and electrical discharges within the plasma zone of the chamber. Fifth embodiment of the invention Figure 63 depicts the components comprised by the fifth embodiment of the invention: ● Plasma Reactor: Plasma reactor chamber comprising a quartz tube with a vacuum connector on each end, and a series of external plasma electrodes attached to it. ● Plasma Power Supply: High frequency and high voltage power supply required for creating a high electrical field and the capacitive transmission of power into plasma using external electrodes. ● Plasma zone: The internal zone of the plasma reactor where the sample is in a biphasic state, consisting of steam produced by the sample's evaporation, and suspended droplets created due to ultrasonic atomization. In this zone, the injected electrical field is strong enough to ionize the gas phase into plasma, and the pressure is low enough to promote its formation more efficiently. ● Plasma Electrodes: External conductive electrodes attached to the reactor's external surface that can inject electrical charges capacitively into the reactor, and create an electrical field large enough to surpass the breakdown voltage of the gas initiating and maintaining the plasma ionization reaction. ● Fiber Optics Probe: Fiber optics cable with an attachment point in its tip which allows the transmission of light emitted by plasma between the outer surface of the Quartz vessel of the plasma reactor to a light spectrometer, made with quartz or other UV transparent material. ● Nebulized Sample: Sample in a biphasic state, consisting of steam produced by the sample's evaporation and suspended droplets created due to ultrasonic atomization. ● Liquid Sample: Sample in its liquid form at the sample feeder, or at the bottom of the nebulization vessel (drain). ● Piezoelectric Ultrasonic Transducer: Standard piezoelectric liquid nebulizer working at partial vacuum pressure. ● Nebulization chamber: Assembly that incorporates the ultrasonic transducer, the external temperature sample fluid controller, and a vacuum vessel. It first regulates the temperature of the liquid sample and injects it into the vacuum vessel, controlling the flash evaporation of the sample, then the remaining liquid sample hits the ultrasonic transducer and it is partially nebulized into a mist. That mist is then injected into the plasma reactor. The remaining condensate accumulates in the bottom of the chamber and it is drained using a peristaltic pump. The nebulization chamber controls the sample inlet temperature, the piezoelectric transducer temperature, and the bottom part of the vessel wall temperature to regulate the drain temperature and control further evaporation. ● Vacuum Circuit: Auxiliary vacuum-rated piping and fittings made to support the plasma reactor and additional instrumentation, connected to the vacuum pump, creating a controlled partial vacuum zone. ● Vacuum Sensor: Digital low-pressure vacuum sensor and indicator used to monitor and control the vacuum level inside the whole circuit. ● Light Spectrometer: Standard high-resolution spectrometer used to analyze the spectra emitted from the plasma reaction. ● Vacuum motorized valve: A motorized valve that restricts the gas flow to regulate the vacuum level. ● Vacuum pump: Digitally controlled vacuum pump to extract the gas flow and create the desired vacuum condition. ● Vacuum controller: Algorithm performed inside the computer unit that receives the signal from the vacuum sensor and regulates the vacuum valve and the vacuum pump to achieve a desired pressure set point. ● Temperature controllers 1,2,3: Control the temperature of the injected sample fluid into the nebulization chamber, the temperature of the piezoelectric ultrasonic transducer, and the temperature of the lower wall of the nebulization vessel. ● Temperature sensors 1,2,3: Temperature sensor feedback used by the temperature controllers for the injected sample fluid into the nebulization chamber, the temperature of the piezoelectric ultrasonic transducer, and the temperature of the lower wall of the nebulization vessel. ● Injector: Part of the nebulization chamber that contains a heat exchanger for regulating the temperature of the inlet sample, and a needle valve that allows the precise dosing of the sample inside the nebulization chamber. ● Chiller: External heat exchanger used to regulate and stabilize the temperature of the cooling fluid that removes or adds heat to the temperature controllers depending on their set points. ● Sample feeder: Vessel that contains the sample to be measured. ● Air Core transformer: Part of the power supply’s impedance matcher circuit for the reactor. ● Computer: The main control unit that centralizes all the data from sensors, controls the actuators, interacts with the user as a human-machine interface, and shows the results of the measurements. An isometric and a front view of the components comprised by the fifth embodiment of the invention can be also observed in Figures 64 and 65. One of the most relevant aspects of this embodiment of the invention is the capability to measure and control some variables that affect the process of introducing samples into the plasma chamber, such as the temperature of critical parts of the system, which is controlled by Peltier cells and thermocouple sensors, as well as a Pirani piezo gauge in conjunction with a regulating valve, in order to set the resulting pressure downstream the reactor due to the suction of the vacuum pump. This and other thermodynamic conditions of the system make it difficult to operate in a stable regimen and, even more so, to reproduce exactly the same operational conditions in order to obtain the same analysis result, within an optimal range of operation, to detect a specific target. The nebulization chamber has a low volume and incorporates a temperature control loop system, allowing control and monitoring the temperature of the sample as it enters the sample injector, as well as the temperature control of piezoelectric transducer. Furthermore, the nebulized sample can be carried from the controlled heating of the sample itself when it reaches the drain, the lowest area of the drain. The design of the reactor is specific for the working frequency of the power source, 13.56 MHz. The dielectric barrier is exposed to the environment, and it is cooled by two fans positioned directly above them. To energize it, an RF inductor coil is connected directly to the electrodes to raise the voltage and generate capacitive plasma from a RF power supply. The system pressure is now monitored in both chambers and the data is logged and adjusted by software, so that the pressure conditions can be adjusted constantly. The nebulizer chamber uses a 2.2 MHz piezoelectric transducer to create a fine mist of water droplets. These droplets are directed into the reactor due to a pressure difference, facilitating the evaporation and atomization of dissolved substances. To ensure a good performance of the piezoelectric transducer, its temperature is kept low by a heat pipe connected to a Peltier element. The nebulization chamber is a conical vessel, with the sample injector on top. Ports in the walls connect the nebulization chamber to the piezoelectric transducer and the plasma chamber. At the bottom, a drainage system removes excess sample material and also, through controlled temperature, generates the vapor that carries the nebulized sample from the piezoelectric transducer. The sample injector introduces the sample into the nebulization chamber, targeting the piezoelectric transducer, regulates the flow rate and controls the sample temperature. The injector is designed to minimize its internal volume to improve the speed of solution change and facilitate cleaning. The fluid is driven through the injector by the pressure difference between the atmosphere and the nebulization chamber. The temperature of the sample passing through the injector is regulated through a Peltier module, connected to a water-cooled heat exchanger. The mass of the injector was reduced to the minimum, to avoid delays in the temperature control response time. The internal channels are narrow enough to rapidly rinse the injector and, at the same time, have enough contact surface to efficiently control the sample temperature. Similarly, the piezoelectric transducer is also connected to a heatpipe to remove the heat that it generates. An aluminum heat sink assembly supports the heatpipe and transfers heat to a Peltier plate, controlling the cooling process. A heat exchanger integrated into a hydraulic cooling circuit is connected to the opposite side of the Peltier plate, as a heat sink for the Peltier plate. This cooling system is fine-tuned to keep the piezoelectric transducer's temperature below 5°C. This temperature control prevents overheating, ensuring that the water does not evaporate immediately upon contact due to the low pressures within the nebulization chamber. An isometric views of the reactor together with the cooling system can be observed in Figures 66 and 67, wherein Figure 67 is a cut view of the cooling system. The drain port in the nebulization chamber plays a critical role in the nebulization process and sample injection. In addition to extracting excess liquid that is not nebulized, the drain controls the temperature and pressure inside the nebulization chamber. Also, the dry vapor generated on the drain walls is used as carrier gas for the nebulized sample. This element comprises an aluminum body with a conical upper surface and a perforation at the center, which connects to a discharge line. The lower surface of the aluminum body is connected to a Peltier plate responsible for controlling its temperature. Below the Peltier plate, a heat exchanger is connected to a refrigerated hydraulic circuit, which is a heat sink to regulate the temperature of the drain port. As described, the nebulization chamber features three Peltier modules designed to maintain precise temperature control at three specific points: the injector, the ultrasonic piezoelectric element and the drain. Each of these modules is in direct contact with heatpipes that transfer heat between these temperature-controlled points and the Peltier modules. The energy dissipation from the Peltier modules is accomplished through copper heat exchangers connected to a chiller. The chiller is adjusted to a specific work temperature, for example, to the piezoelectric port, the Peltier controls the temperature at 5 Celsius degrees, while at the sample injector the temperature is set at 10 ºC. The plasma chamber has a quartz tube core with dielectric barrier electrodes, very limited in size due to the high frequency at which the power source works. Additionally, a fiber optic port places an optical fiber directly on the surface of the reactor's quartz core. The plasma chamber core is cooled by two cooling fans, positioned directly above the electrodes. The electrodes are energized by cables connected to a radiofrequency Inductor coil. To facilitate reactor connections to nebulization and vacuum systems, the reactor uses a stainless- steel fitting type connector equipped with an O-ring type KF 25 gasket, a standard in vacuum systems. The reactor core assembly and the RF inductor coil are confined in a Faraday cage, to avoid problems due to radiofrequency radiation. The core is made of synthetic fused quartz tube, a transparent glass with high optical transmission. The tube is 300 mm long, 6.98 mm inner diameter and 10.95 mm outer diameter. A graphite coating is applied to the outer surface of the tube, on which copper is electroplated. This coated surface forms the electrode of the reactor, which is 50 mm long and separated by a gap of 16.5 mm. The quartz tube is coupled to a 1 / 2" KF 25 O-ring type stainless steel connector at each end. The plasma chamber is powered by a 600 W 13.56 MHz power generator, featuring a solid-state design that ensures precise and consistent power control, along with a stable output. It serves a versatile role as both source or bias generator, supporting continuous operation or functioning as a stand-alone batch tool. To safeguard against excessive Voltage Standing Wave Ratio (VSWR) conditions, the power generator incorporates protective measures. These include the limitation of reflected power, power amplifier current, and power amplifier transistor dissipation. This ensures a reliable and efficient operation, contributing to the device's longevity and stability in various industrial applications. The power generator operates along with an impedance matcher, equipped with microprocessor- controlled stepper motor drives and advanced fuzzy logic tuning algorithms. The matching system rapidly transforms plasma impedances to 50 ohms to maximize power transfer to the plasma chamber, ensuring higher consistency and accuracy than traditional analog-based tuning methods. To create the required electrical fields, it was implemented an additional air-cored transformer and inductive impedance matcher. Another critical component to ensure optimal performance is the vacuum pump, which plays a key role in maintaining the specific pressure conditions required. To this end, it was selected a vacuum pump with a free air capacity of 7.5 CFM / 10 m3 / h (Edwards nXDS10iC). The vacuum pump is connected to the plasma chamber through a vacuum seat valve, coupled to a stepper motor that controls the opening of the valve. The motor is connected to the control system, which allows fine-tuning the valve opening and, therefore, the entire system’s vacuum level. The vacuum level is measured with a combined Piezoresistive and Pirani sensor gauge (Busch VACTEST) featuring a KF25 connection port. It is linked to a line connecting the nebulization chamber and the discharge chamber. This instrument is integrated into a control interface and data logger application. Finally, Figure 68 shows a preferred alternative of the fifth embodiment of the invention, wherein the system is disposed with a mass spectrometer, wherein the positively charged fragments of molecules are separated according to their mass-to-charge ratio, for example, by accelerating them and subjecting them to an electric or magnetic field, using said mass spectrometer; which delivers data that is analyzed using a neural network. Validation Test of the fifth embodiment of the invention The fifth embodiment of the invention has been tested with several challenge waters to assess its capability to detect metal ions and volatile organic compounds. The targets of a validation test are summarized in the following table. In all cases the analytes were detected successfully. The obtained spectra were plotted to identify the peaks corresponding to each analyte, as shown below. Bidistilled Water sample (background) Figure 69 shows the spectrum from bidistilled water, which is used as control substance and 0% concentration indicator. Water generates peaks from H(alpha) at 656.3 nm, H(Beta) 486.1 nm, -OH ~309 nm; and Oxygen at 777.4 nm and 844.6 nm. Metal Ions Lithium ions at 1 mg / L: Lithium generates a peak at 670.8 nm (see Figure 70). Potassium ions at 1 mg / L: Potassium generates a doublet of peaks at 766.5 / 770 nm (see Figure 71). Sodium ions at 1 mg / L: Sodium generates a peak at 589.5 nm (see Figure 72). Combined Li, Na and K ions at 10 mg / L: These elements, when combined in a single sample, generate the same peaks as they do separately, but with a higher intensity (see Figure 73). Combined Mg, Ca and Zn ions at 10 mg / L: These elements were not detected as easily as the ions in previous tests. However, the analysis revealed their presence, even in trace concentrations. It is important to note that magnesium detection was hindered due to overlapping emissions with -OH groups (see Figure 74). Volatile organic compounds Another test was performed with three similar Volatile Organic Compounds (VOC), each one separately and combined in one solution. In this sense, Figures 75, 76 and 77 show the spectrum for samples containing isopropanol at 1% v / v, ethanol at 1% v / v and acetone at 1% v / v. Finally, Figures 78 and 79 show comparison between samples containing ethanol, isopropanol and acetone at 1% v / v. Although the spectral lines of these compounds may appear quite similar at first glance, closer examination allows to discern subtle variations in peak positions and intensities, thereby enabling to distinguish them from one another.

Claims

CLAIMS 1) A method for real-time, multi-parameter monitoring of fluid quality, CHARACTERIZED in that it comprises the steps of: a) transiently transforming a continuous stream of the fluid into non-thermal plasma using at least one dielectric barrier discharge plasma chamber; b) subjecting the liquid to a pressure drop, generating a biphasic liquid-gas stream; c) continuously ionizing the biphasic liquid-gas stream through a controlled electric field, produced by at least one dielectric barrier electrode; d) channeling at least one molecular or atomic emission toward a spectrum analysis module; e) detecting the at least one molecular or atomic emission through the spectrum analysis module; and f) analyzing the at least one molecular or atomic emission through the spectrum analysis module. 2) The method according to claim 1, CHARACTERIZED in that it further comprises determining the type of element corresponding to said at least one molecular or atomic emission through the spectrum analysis module. 3) The method according to any of claims 1 to 2, CHARACTERIZED in that step a) further comprises producing a series of electrical micro-discharges repeatedly at a frequency of 250 kHz. 4) The method according to any of claims 1 to 3, CHARACTERIZED in that step c) further comprises varying the electric field according to the required energy level for the non-thermal plasma. 5) The method according to any of claims 1 to 4, CHARACTERIZED in that step c) is carried out inside the at least one dielectric barrier discharge plasma chamber. 6) The method according to any of claims 1 to 4, CHARACTERIZED in that step c) is carried out outside the at least one dielectric barrier discharge plasma chamber. 7) The method according to any of claims 1 to 6, CHARACTERIZED in that the type of element determined in step h) corresponds to one or more of the group consisting of: volatile compounds, organic compounds, volatile organic compounds, dissolved ions, and atomic emissions. 18) The method according to any of claims 1 to 7, CHARACTERIZED in that it further comprises connecting the at least one plasma reactor to a bypass pipe, from a larger pipe or tank, to obtain a smaller flow of the target fluid to be analyzed. 9) The method according to any of claims 1 to 7, CHARACTERIZED in that it further comprises reinjecting or discarding the analyzed fluid. 10) The method according to any of claims 1 to 8, CHARACTERIZED in that it further comprises reinjecting the analyzed fluid when there is no variation of more than 1% in the water composition. 11) The method according to any of claims 1 to 8, CHARACTERIZED in that it further comprises discarding the analyzed fluid when there is at least 15% of a determined type of element present in the fluid composition. 12) The method according to any of claims 1 to 11, CHARACTERIZED in that it further comprises providing the electrical conditions to maintain a stable plasma condition through electrical means. 13) The method according to claim 12, CHARACTERIZED in that it further comprises using electrical energy from a 220 V and 50 Hz power grid, converting it within an adjustable range of continuous voltage between 0 and 400 V, using an AC / DC converter. 14) The method according to any of claims 12 to 13, CHARACTERIZED in that it further comprises transforming the continuous voltage signal into a modified sinusoidal alternating signal with an adjustable frequency, using an inverter. 15) The method according to any of claims 12 to 14, CHARACTERIZED in that it further comprises filtering the voltage wave and amplifying it through a resonator circuit, formed by an inductor and a capacitor. 16) The method according to claim 15, CHARACTERIZED in that it further comprises adjusting the voltage and current levels required by the at least one plasma chamber in the ionization stage, using a transformer. 217) The method according to any of claims 1 to 16, CHARACTERIZED in that it further comprises, before step a), nebulizing the fluid to inject it into the dielectric barrier discharge plasma chamber, using an ultrasonic nebulizer. 18) The method according to any of claims 1 to 17, CHARACTERIZED in that it further comprises, before step a), applying vacuum in the dielectric barrier discharge plasma chamber, using a vacuum pump. 19) A system for real-time, multi-parameter monitoring of water quality, CHARACTERIZED in that it comprises: - at least one dielectric barrier discharge plasma chamber, which transiently transforms a continuous stream of the fluid into non-thermal plasma, and which subjects the liquid to a pressure drop, generating a biphasic liquid-gas stream; - at least one dielectric barrier electrode, which continuously ionizes the biphasic liquid-gas stream through a controlled electric field; and - a spectrum analysis module operating in conjunction with a neural network, which channels, detects and analyzes at least one molecular or atomic emission. 20) The system according to claim 18, CHARACTERIZED in that the at least one dielectric barrier discharge plasma chamber comprises a dielectric barrier, which is made of one or more of alumina, zirconium, quartz, and borosilicate glass. 21) The system according to any of claims 18 to 19, CHARACTERIZED in that the at least one dielectric barrier discharge plasma chamber further comprises a quartz window inserted in its center, which allows connecting the at least one dielectric barrier discharge plasma chamber to the analysis module, through the at least one fiber optic cable. 22) The system according to any of claims 18 to 20, CHARACTERIZED in that it further comprises electrical means, which provide the electrical conditions to maintain a stable plasma condition. 23) The system according to claim 21, CHARACTERIZED in that the electrical means comprise an AC / DC converter, which uses electrical energy from a 220 V and 50 Hz power grid, and converts it within an adjustable range of continuous voltage between 0 and 400 V. 324) The system according to any of claims 21 to 22, CHARACTERIZED in that the electrical means further comprise an inverter, which transforms the continuous voltage signal into a modified sinusoidal alternating signal with an adjustable frequency. 25) The system according to any of claims 21 to 23, CHARACTERIZED in that the electrical means further comprise a resonator circuit, which comprises a resonant tank, formed by an inductor and a capacitor, that filters the voltage wave and amplifies it. 26) The system according to claim 24, CHARACTERIZED in that the electrical means further comprise a transformer, which adjusts the voltage and current levels required by the at least one plasma chamber in the ionization stage. 27) The system according to any of claims 18 to 25, CHARACTERIZED in that it further comprises a spectral sensor. 28) The system according to any of claims 18 to 26, CHARACTERIZED in that it further comprises an ultrasonic nebulizer, which nebulizes the fluid to inject it into the dielectric barrier discharge plasma chamber. 29) The system according to any of claims 18 to 27, CHARACTERIZED in that it further comprises a vacuum pump, which applies vacuum in the dielectric barrier discharge plasma chamber. 4

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