Sample injection atomization processing device and system thereof, method for measuring sample

Abstract

The application belongs to the technical field of detection and analysis of volatile organic compounds in water. The application provides a sample injection atomization treatment device, which comprises a buffer cavity, a first pipeline, a second pipeline, a third pipeline, a first interface and a second interface. The buffer cavity is a cavity with a certain shape. The outer layer of the buffer cavity has a heating layer. The first interface is arranged at the top or vertex of the rear end of the buffer cavity. The second interface is arranged near the first interface. The first pipeline and the second pipeline are symmetrically arranged at the front end of the buffer cavity and are inclined at a certain angle. The outlet of the second pipeline is aligned with the outlet of the first pipeline. The third pipeline is arranged on the first pipeline. The central axis position of the third pipeline is vertically opposite to the central axis position of the first pipeline. The diameter of the third pipeline is smaller than that of the first pipeline. A small hole smaller than the diameter of the third pipeline is arranged at the communication position of the third pipeline and the first pipeline. The device of the application is more accurate in detecting the concentration of VOCs components.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of detection and analysis of volatile organic compounds in water. BACKGROUND

[0002] PTR-TOF uses a proton transfer ion source, which is a soft ionization method. Organic molecules are ionized into ions by H3O + or other reagent ions. Different mass number ions are detected after passing through the flight chamber at different speeds. PTR-TOF mainly uses a direct sampling method when monitoring organic compounds. The gas is introduced into the device through pipes, valves, pumps, etc., and finally analyzed to obtain the results.

[0003] The purge and trap + thermal desorption + GC / GCMS technical scheme is to pass a constant flow rate of inert gas through the sample within a fixed time, to sweep the VOCs in the sample into the headspace above the sample and transmit them to a trap containing an adsorbent, and then heat and backflush the adsorbent with carrier gas to transmit the desorbed analysis sample to the downstream detection equipment for determination.

[0004] The membrane separation + SPI mass spectrometer technical scheme is to separate VOCs from water by using PDMS and other semi-permeable membranes with the help of the osmotic pressure difference between the two sides of the membrane, and then transmit the VOC components to an online mass spectrometer such as SPI mass spectrometer for analysis.

[0005] The commonly used technical means such as GCMS, LCMS, gas chromatography, etc. require a long pretreatment and analysis time, and the online monitoring technology such as SPI-MS has poor analysis effect on halogenated hydrocarbons and other common water pollutants. Because VOCs in water are usually extracted by headspace, adsorption desorption or semi-permeable membrane permeation, etc. and then sent to the instrument for analysis, the above methods cannot guarantee that the concentration and proportion of VOC components converted into gas state are consistent with those in water, and it is time-consuming and labor-intensive. Atomization is generally used more in the detection of particulate matter. After atomization, it is dried by silica gel, etc. but it is generally difficult to accurately quantify the production. Because part of the particles collide and flow back during atomization, and there is also loss during the drying process, the actual concentration produced cannot be accurately estimated. When VOCs in water are atomized, the concentration of some VOC components is greatly affected by the drying treatment of nanofiltration, molecular sieve, silica gel, etc. resulting in that the final detection result does not match the actual situation; if no drying treatment is performed, the H2O content after sample atomization is very high, which on the one hand affects the service life of the instrument, and on the other hand also interferes with the detection performance of the instrument. SUMMARY

[0006] In view of the above, the present application provides a sample injection atomization treatment device, comprising a buffer cavity, a first pipeline, a second pipeline, a third pipeline, a first interface, and a second interface; the buffer cavity is a cavity with a certain shape; the buffer cavity has a heating layer on its outer layer; the first interface is arranged at the top of the rear end of the buffer cavity or at the vertex; the second interface is arranged near the first interface; the first pipeline and the second pipeline are symmetrically arranged at the front end of the buffer cavity and are inclined at a certain angle; the outlet of the second pipeline is aligned with the outlet of the first pipeline; the third pipeline is arranged on the first pipeline, the central axis position of the third pipeline is vertically opposite to the central axis position of the first pipeline, the diameter of the third pipeline is smaller than that of the first pipeline; a small hole smaller than the diameter of the third pipeline is arranged at the position where the third pipeline communicates with the first pipeline.

[0007] In a specific embodiment of the present application, the buffer cavity is a tubular buffer cavity.

[0008] Further, the material of the tubular buffer cavity is quartz glass.

[0009] Further, the length of the tubular buffer cavity is not less than 20 cm and the diameter is not less than 8 cm.

[0010] In a specific embodiment of the present application, the first interface communicates with a PTR-TOF.

[0011] In a specific embodiment of the present application, the second interface communicates with a sampling pump.

[0012] In a specific embodiment of the present application, the diameter of the third pipeline is 3 mm.

[0013] In a specific embodiment of the present application, the first pipeline and the second pipeline are inclined at an angle of 30 to 45 degrees.

[0014] In a specific embodiment of the present application, the length and diameter of the first pipeline and the second pipeline are the same; the diameter is 6 mm.

[0015] In a specific embodiment of the present application, the diameter of the small hole of the third pipeline is 0.3 mm.

[0016] In a specific embodiment of the present application, the length of the third pipeline is 3-5 cm.

[0017] The application further provides a sample injection atomization treatment system, which comprises the sample injection atomization treatment device, a pure water interface, a first industrial injection pump, a water sample standard sample interface, a second industrial injection pump, a three-way electromagnetic valve, a first mass flow controller, a first three-way joint, a second mass flow controller, a high-purity N2 interface, a second three-way joint, a third mass flow controller and a standard gas interface.

[0018] Thirdly, the application further provides a method for PTR-TOF calibration by using a standard liquid through the sample injection atomization treatment system, which comprises the following steps: the second industrial injection pump injects the quantitative standard liquid into the third pipeline through the opened three-way electromagnetic valve through the water sample standard sample interface, and the two input pipelines of the first pipeline and the second pipeline are both high-purity nitrogen gas, the flow rate of which is controlled by the first mass flow controller and the second mass flow controller and is 1 L / min, and the third mass flow controller is set to 0.

[0019] Fourthly, the application provides a method for PTR-TOF calibration by using a standard gas through the sample injection atomization treatment system, which comprises the following steps: the high-purity nitrogen gas in the first pipeline carries the quantitative pure water in the third pipeline and mixes with the mixed gas of the standard gas and the high-purity nitrogen gas in the second pipeline; the pure water in the third pipeline is injected into the quantitative pure water calculated according to the humidity value of the sample to be measured by the first industrial injection pump; the input of the first pipeline is high-purity nitrogen gas, the flow rate of which is controlled by the first mass flow controller and is 1 L / min; the standard gas and the high-purity nitrogen gas input into the second pipeline are mixed gas mixed by the three-way joint, and the standard gas and the high-purity nitrogen gas in the second pipeline are controlled by the second mass flow controller and the third mass flow controller, respectively; the standard gas in the second pipeline is obtained after calculation according to the standard gas concentration and the required standard gas concentration; the sum of the flow rates of the second mass flow controller and the third mass flow controller is 1 L / min.

[0020] Fifth, the present application provides a method for PTR-TOF blank determination using a sample injection atomization treatment system, comprising the following steps: a first industrial injection pump injects a quantitative amount of pure water calculated according to the humidity value of the sample to be measured into the third pipeline through a three-way electromagnetic valve, while the two inputs of the first pipeline and the second pipeline are high-purity nitrogen gas, and the flow rates controlled by the first mass flow controller and the second mass flow controller are both 1 L / min, and the third mass flow controller is set to 0.

[0021] Sixth, the present application provides a method for PTR-TOF sample determination using a sample injection atomization treatment system, comprising the following steps: a second industrial injection pump injects a quantitative amount of water sample into the third pipeline through a water sample / standard sample interface through a three-way electromagnetic valve, while the two inputs of the first pipeline and the second pipeline are high-purity nitrogen gas, and the flow rates controlled by the first mass flow controller and the second mass flow controller are both 1 L / min, and the third mass flow controller is set to 0.

[0022] The device and method of the present application can adapt to different concentrations of VOCs in water, and can be calibrated using standard gas or standard liquid respectively, and ensure that the determination conditions (such as humidity) of the standard sample and the blank sample are consistent with the actual water sample, avoiding affecting the accuracy of the monitoring data. The PTR-TOF used in the present application can quickly monitor atmospheric samples, and the ion source of the PTR-TOF is a H3O + , O2 + , NO + and other chemical ions generated by ionizing wet air through glow discharge, which has more analyte species than SPI and other online mass spectrometers, and has good analysis effect on common VOCs in water. At the same time, through atomization, the quantitative water sample is all dispersed into particles, then diluted and mixed into a uniform gas state by high-purity nitrogen gas, so that all VOCs components in the water sample enter the gaseous state, and the relative proportions of the components remain consistent, so that the quantitative detection result can accurately reflect the concentration of each component of VOCs in the water sample. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a sample injection atomization treatment device diagram.

[0024] Among them, 1 is a buffer cavity, 2 is a first pipeline, 3 is a second pipeline, 4 is a first interface, 5 is a second interface, and 6 is a third pipeline.

[0025] Figure 2 is a sample injection atomization treatment system diagram.

[0026] Wherein, 1 is a buffer cavity, 2 is a first pipeline, 3 is a second pipeline, 4 is a first interface, 5 is a second interface, 6 is a third pipeline, 7 is a pure water interface, 8 is a first industrial injection pump, 9 is a water sample standard sample interface, 10 is a second industrial injection pump, 11 is a three-way electromagnetic valve, 12 is a first mass flow controller, 13 is a first three-way joint, 14 is a second mass flow controller, 15 is a high-purity N2 interface, 16 is a second three-way joint, 17 is a third mass flow controller, 18 is a standard gas interface, DETAILED DESCRIPTION

[0027] PTR-TOF: Proton Transfer Reaction Time-of-Flight Mass Spectrometry.

[0028] EMBODIMENT

[0029] The application discloses a volatile organic compound analysis method based on PTR-TOF, and realizes rapid detection of volatile organic compounds in water bodies. The application converts volatile organic compounds in water into a gaseous state through an atomizing device, and guides the gaseous components into a PTR-TOF for monitoring under the condition of whole-process heating.

[0030] In the application, a sample injection and atomization treatment device is designed to connect a front-end sample and a rear-end detection equipment, and comprises a buffer cavity, a first pipeline, a second pipeline, a first interface, a second interface and a third pipeline.

[0031] The buffer cavity is a cavity with a certain shape, and is used for providing a mixing space for the sample. The buffer cavity is provided with a heating layer on an outer layer, and can be preferably in a circular tube shape. The material of the buffer cavity is preferably quartz glass, and heating wires or the like are additionally arranged outside the tube for heating, so that the buffer cavity can be kept at a certain temperature or temperature range, thereby avoiding excessive adsorption of VOCs and the like. The length of the circular tube-shaped buffer cavity is not less than 20 cm, and the diameter is not less than 8 cm.

[0032] The first interface is arranged at the top or vertex of the rear end of the buffer cavity, and is connected with the PTR-TOF. The PTR-TOF collects the sample to be detected in the buffer cavity through the first interface. The PTR-TOF sampling rate can be set to 180 mL / min.

[0033] The second interface is arranged near the first interface, and is connected with a sampling pump. The sampling pump provides power for the transmission of the gas in the buffer cavity from the front end to the rear end through the second interface.

[0034] The first pipeline and the second pipeline are oppositely arranged at the front end of the buffer cavity and are inclined at an angle, preferably 30 to 45 degrees; the gas outlets of the first pipeline and the second pipeline are opposite at an angle, the inclination angles of the first pipeline and the second pipeline are the same, preferably 30 to 45 degrees, and the gases in the two pipelines can collide with each other, be diluted and atomized. The diameters and lengths of the first pipeline and the second pipeline are equal, the diameter is preferably 6 mm, and the length is preferably 10 cm. The gas outlet of the second pipeline is near the gas outlet of the first pipeline, and the gas in the second pipeline is used to dilute and atomize the gas in the first pipeline.

[0035] A third pipeline is further arranged on the first pipeline, the third pipeline is used for passing water sample / standard solution / pure water, the diameter of the third pipeline is smaller than that of the first pipeline and the second pipeline, and the diameter of the third pipeline is 3 mm. The central axis position of the third pipeline is vertically opposite to the central axis position of the first pipeline, the third pipeline is cylindrical, and the outlet position of the third pipeline has a small hole, and the small hole is located at the central axis position. The length of the third pipeline is 3-5 cm, and the position connected with the first pipeline ensures that the outer end of the first pipeline is about 3-5 cm long. The diameter of the small hole of the third pipeline is 0.3 mm, and after the liquid enters from the small hole, the flow rate increases and collides with the opposite pipe wall to produce atomization effect, and is wrapped into the middle buffer cavity by the high-purity N2 in the first pipeline.

[0036] The first pipeline is used for conveying a flow of high-purity N2 into the buffer cavity, and the flow is 1 L / min.

[0037] The second pipeline is used for conveying standard gas or high-purity N2 into the buffer cavity, and the flow is 1 L / min. The outlet of the second pipeline is aligned with the outlet of the first pipeline, and the two gas streams in the two pipelines collide at the outlet, so that the liquid in the third pipeline is further formed into a uniform gaseous sample.

[0038] The sample injection atomization processing system comprises a sample injection atomization processing device, a pure water interface, a first industrial injection pump, a water sample standard sample interface, a second industrial injection pump, a three-way electromagnetic valve, a first mass flow controller, a first three-way joint, a second mass flow controller, a high-purity N2 interface, a second three-way joint, a third mass flow controller, and a standard gas interface.

[0039] One end of the third pipeline is connected with the first interface pipeline of the three-way electromagnetic valve; the second interface of the three-way electromagnetic valve is connected with the first industrial injection pump and the pure water interface in sequence; and the third interface of the three-way electromagnetic valve is connected with the second industrial injection pump and the water sample standard sample interface in sequence.

[0040] One end of the first pipeline is connected to the first mass flow controller and the first interface of the first three-way joint in sequence through the pipeline, the second interface of the first three-way joint is connected to the high-purity N2 interface through the pipeline; the third interface of the first three-way joint is connected to the second mass flow controller and the first interface of the second three-way joint in sequence through the pipeline; the second interface of the second three-way joint is connected to the third mass flow controller and the standard gas interface in sequence through the pipeline; the third interface of the second three-way joint is connected to one end of the second pipeline through the pipeline.

[0041] PTR-TOF calibration method by sample atomization treatment system:

[0042] 1. Method for calibrating the system with standard solution

[0043] When calibrating with standard solution, the second industrial injection pump injects the quantitative standard solution into the third pipeline through the opened three-way electromagnetic valve through the water sample standard interface, and the two input paths of the first pipeline and the second pipeline are high-purity nitrogen gas, the flow rate controlled by the first mass flow controller and the second mass flow controller is 1L / min, and the flow rate set by the third mass flow controller is 0.

[0044] 2. Method for calibrating the system with standard gas

[0045] When calibrating with standard gas, the high-purity nitrogen gas in the first pipeline carries the quantitative pure water in the third pipeline and mixes with the mixed gas of the standard gas and high-purity nitrogen gas in the second pipeline; the pure water in the third pipeline is injected by the first industrial injection pump to obtain the quantitative pure water calculated according to the humidity value of the sample to be measured, so as to ensure that the final gaseous standard sample humidity is consistent with the sample to be measured; the input of the first pipeline is high-purity nitrogen gas with a flow rate of 1L / min controlled by the first mass flow controller; the mixed gas of the standard gas and high-purity nitrogen gas in the second pipeline is mixed by the three-way joint, and the standard gas and high-purity nitrogen gas in the second pipeline are controlled by the second mass flow controller and the third mass flow controller; the standard gas in the second pipeline is obtained after calculation according to the standard gas concentration and the required standard gas concentration; the flow rate of the second mass flow controller and the third mass flow controller is 1L / min, that is, the total flow rate of the second pipeline is 1L / min. For example, when the standard gas flow rate is 100mL, the high-purity nitrogen gas is 900mL.

[0046] PTR-TOF blank determination method by sample atomization treatment system:

[0047] When the blank test is performed, the first industrial injection pump injects a quantitative pure water calculated according to the humidity value of the to-be-tested sample into the third pipeline through the three-way electromagnetic valve, so that the final gaseous standard sample humidity is consistent with that of the to-be-tested sample, and the two-way input of the first pipeline and the second pipeline is high-purity nitrogen gas, the flow rate controlled by the first mass flow controller and the second mass flow controller is 1L / min, and the third mass flow controller is set to 0.

[0048] The PTR-TOF sample determination method is performed on the sample atomization treatment system.

[0049] The second industrial injection pump injects a quantitative water sample into the third pipeline through the water sample standard sample interface through the three-way electromagnetic valve, and the two-way input of the first pipeline and the second pipeline is high-purity nitrogen gas, the flow rate controlled by the first mass flow controller and the second mass flow controller is 1L / min, and the third mass flow controller is set to 0.

[0050] The beneficial technical effects of the present application are as follows:

[0051] (1) After the quantitative water sample is atomized into particles, the particles are mixed into a uniform gas by two-way high-purity nitrogen gas collision, so that all VOCs components in the water sample enter the gas state, and the relative proportion of each component remains consistent with that in the original water sample, so that the quantitative detection result can accurately reflect the concentration of each component of VOCs in the water sample.

[0052] (2) The present application does not perform drying treatment, so that adsorption or selective removal of VOCs components is avoided, and the measurement accuracy of the sample is ensured.

[0053] (3) In the present application, high-purity dry nitrogen gas is used as a carrier gas to dilute the atomized water sample, so that the water content is reduced, and the PTR-TOF used in the present application can not be affected by the low water content in the sample, and the high sensitivity of the PTR-TOF ensures that the sample can be successfully detected after dilution.

[0054] (4) In the present application, the measurement conditions (such as temperature and humidity) of the system are consistent during the blank test, calibration and sample measurement, so that the effectiveness of the calibration curve is ensured, and the purpose of accurate measurement is achieved.

[0055] (5) The same system can be calibrated by standard liquid and standard gas

[0056] (6) The temperature and humidity during the calibration and measurement process are completely consistent

[0057] The device and method of the present application can adapt to different concentrations of VOCs in water, and can be calibrated by standard gas or standard liquid respectively, and ensure that the determination conditions (such as humidity) of standard samples and blank samples are consistent with the actual water sample, so as to avoid affecting the accuracy of monitoring data. The PTR-TOF used in the present application can quickly monitor atmospheric samples, and the ion source of PTR-TOF is H3O + , O2 + , NO + and other chemical ions generated by ionizing wet air through glow discharge, compared with SPI and other online mass spectrometers, more analyte species, and better analysis effect on common VOCs in water. At the same time, through atomization, the quantitative water sample is all dispersed into particles, then diluted and mixed into uniform gaseous state by high-purity nitrogen, so that all VOCs components in the water sample enter into gaseous state, and the relative proportion of each component remains consistent, so that the quantitative detection result can accurately reflect the concentration of each component of VOCs in the water sample.

[0058] The present application can also replace the atomization method, such as ultrasonic atomization; can replace the detection equipment, such as SPI-MS. After the above-mentioned replacement, the whole system will have some differences, such as when using ultrasonic atomization, necessary components such as pump and flow meter need to be added to introduce the sample, which will produce some adsorption and other influences; when using SPI-MS and other detection equipment, the detection effect of some VOCs components is not good. But through the above-mentioned modification, the monitoring of VOCs in water can also be realized, and it does not deviate from the overall idea of the present application.

Claims

1. A sample introduction atomization processing system, comprising: The sample injection atomization treatment device, pure water interface, first industrial injection pump, water sample standard sample interface, second industrial injection pump, three-way electromagnetic valve, first mass flow controller, first three-way joint, second mass flow controller, high-purity N2 interface, second three-way joint, third mass flow controller, and standard gas interface are connected in sequence through pipelines. The sample injection atomization treatment device comprises a buffer cavity, a first pipeline, a second pipeline, a third pipeline, a first interface, and a second interface. The buffer cavity is a cavity with a certain shape. The first interface is arranged at the top of the rear end of the buffer cavity. The second interface is arranged near the first interface. The first pipeline and the second pipeline are symmetrically arranged at the front end of the buffer cavity and are inclined at a certain angle. The outlet of the second pipeline is aligned with the outlet of the first pipeline. The angle of inclination of the first pipeline and the second pipeline is 30 to 45 degrees. The third pipeline is arranged on the first pipeline. The third pipeline is connected to the first pipeline. The second interface of the three-way electromagnetic valve is connected to the first industrial injection pump and the pure water interface in sequence through pipelines. The third interface of the three-way electromagnetic valve is connected to the second industrial injection pump and the water sample standard sample interface in sequence through pipelines. One end of the first pipeline is connected to the first mass flow controller and the first interface of the first three-way joint in sequence through pipelines. The second interface of the first three-way joint is connected to the high-purity N2 interface through a pipeline. The third interface of the first three-way joint is connected to the second mass flow controller and the first interface of the second three-way joint in sequence through pipelines. The second interface of the second three-way joint is connected to the third mass flow controller and the standard gas interface in sequence through pipelines. The third interface of the second three-way joint is connected to one end of the second pipeline through a pipeline.

2. The sample introduction atomization treatment system according to claim 1, characterized by The buffer cavity is a tubular buffer cavity.

3. The sample introduction and atomization system of claim 2, wherein The tubular buffer cavity is made of quartz glass.

4. The sample introduction and atomization system of claim 2, wherein The length of the tubular buffer cavity is not less than 20 cm, and the diameter is not less than 8 cm.

5. The sample introduction and atomization system of claim 1 wherein, The length and diameter of the first pipeline and the second pipeline are the same.

6. The sample introduction atomization processing system of claim 1, wherein The length of the third pipeline is 3-5 cm.

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