Test method for analysis of properties of lotus plumule extract

Abstract

The application relates to the field of material analysis, and discloses a test method for analyzing the properties of lotus plumule extract, which comprises the following steps: introducing the lotus plumule extract to be detected into a flow detection pool to establish a transient electrically induced birefringence monitoring field; applying a high-frequency bipolar symmetric square wave electric field to an excitation electrode pair; using the polarity high-frequency switching characteristic to limit the displacement of free ions within a local perturbation range, and simultaneously inducing the electric dipole orientation arrangement of alkaloid molecules; removing the electric field; monitoring and recording the transient birefringence decay trajectory data; and processing the data to separate the spin relaxation time constants belonging to different components, and determining the contents of nuciferine, isonor-lausplumuline and methylnuciferine according to the mapping rule between the constants and the effective hydrodynamic radius of molecules. The application realizes the physical decoupling of overlapping signals in the time domain through the spin relaxation characteristic, effectively suppresses the ionization interference of a complex matrix, and ensures the stability of a detection baseline.

Description

Technical Field

[0001] This invention relates to a test method for the property analysis of lotus seed heart extract, belonging to the field of materials analysis technology. Background Technology

[0002] Currently, the composition ratios of dibenzylisoquinoline alkaloids such as methyl lotusine, lotusine, and isolivineine in lotus seed heart extract are related to their pharmacological activities. Determining the content of these alkaloids is a key step in the quality control of natural products. The current mainstream technology uses high-performance liquid chromatography (HPLC), which utilizes the physical steric hindrance effect of fixed phases on solute molecules to perform qualitative and quantitative analysis of each component, providing high detection reliability.

[0003] As natural product extraction processes evolve towards continuous production, online quality control demands high detection timeliness. The time lag inherent in chromatographic analysis limits real-time feedback of process parameters. Some solutions employ ultraviolet spectroscopy, utilizing molecular energy level transitions for rapid determination. However, in the high-conductivity matrix of industrial extracts, homologous molecules exhibit similar energy level transition characteristics, leading to overlapping absorption spectra under steady-state detection conditions and decreased group resolution. Attempts to use mathematical fitting models to isolate signals are prone to baseline drift due to background interference when the extract matrix composition fluctuates. Simply increasing the excitation field strength to improve the signal-to-noise ratio can induce directional charge migration within the solution, resulting in Joule heating that disrupts the fluid's optical homogeneity, thus compromising measurement accuracy and system performance. Stability conflicts arise. For example, Chinese invention patent CN101786984B discloses a method for extracting lotusine, isolivineine, and methyl lotusine from lotus seeds. This method utilizes high-speed countercurrent chromatography for separation, relying on the difference in the partition coefficient of the solute in the two-phase solvent system. The purification of all components is time-consuming and requires control of the solvent ratio. Based on the overall interphase partitioning mode, there is a physical response misalignment when facing the need for second-level feedback in continuous production. Background fluctuations in the fluid flow state mask the surface concentration characteristics. Using a mathematical fitting model to peel off the signal is prone to baseline drift due to background interference when the matrix composition of the extract fluctuates. Increasing the excitation field strength to improve the signal-to-noise ratio can induce charge directional migration, generating Joule heating effect that destroys the optical homogeneity of the fluid, thus causing a conflict between measurement accuracy and system stability.

[0004] Therefore, how to utilize the differences in surface physical dimensions of homosomes to achieve highly specific in-situ identification of alkaloid components while maintaining fluid flow is the technical problem to be solved by this invention. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A test method for the property analysis of lotus seed heart extract, comprising:

[0006] Step S101: The lotus seed heart extract to be tested is continuously introduced into a flow detection cell equipped with a polarization optical detection path and an excitation electrode pair, so that the detection beam passes through the flow detection cell and a transient electrically induced birefringence monitoring field is established for the lotus seed heart extract to be tested; the lotus seed heart extract to be tested contains lotusine, isoligusine and methyl lotusine in a dissolved state.

[0007] Step S102: Apply a high-frequency bipolar symmetrical square wave electric field to the excitation electrode pair. Utilize the high-frequency polarity switching characteristics of the high-frequency bipolar symmetrical square wave electric field to restrict the displacement vector of free ions in the lotus seed extract to be tested within the local perturbation range, suppress the overall polarization interference generated by the electrolyte matrix, and use the electric field vector to induce the electric dipole orientation of bisbenzylisoquinoline alkaloid molecules in the lotus seed extract to be tested.

[0008] Step S103: After the bisbenzylisoquinoline alkaloid molecules reach a saturated orientation equilibrium state, the high-frequency bipolar symmetrical square wave electric field is removed, and the transient birefringence attenuation trajectory data of the lotus seed extract to be tested after the electric field disappears is monitored and recorded synchronously through the polarization optical detection path.

[0009] Step S104: Multi-exponential fitting identification is performed on the transient birefringence attenuation trajectory data to separate the rotational relaxation time constants belonging to different molecular particle size components. Based on the cubic monotonic mapping law between the rotational relaxation time constant and the effective hydrodynamic radius of the molecule, the component identification results and content analysis data of lotusine, isolivineine, and methyl lotusine in the lotus seed heart extract to be tested are determined by the rotational relaxation difference of each component on the time scale.

[0010] Preferably, step S102 includes: step S1021, controlling the frequency of the high-frequency bipolar symmetrical square wave electric field to be 100kHz to 500kHz, and the peak-to-peak value of the field strength to be 200V / cm to 800V / cm; the voltage integral value of the high-frequency bipolar symmetrical square wave electric field in one complete cycle is 0, which is used to maintain an electrically neutral environment on the surface of the excitation electrode pair, suppress the generation of electrolytic bubbles and refractive index gradient noise induced by Joule heating in the flow detection cell, so as to stabilize the detection baseline of the polarization optical detection path.

[0011] Preferably, step S101 includes: step S1011, controlling the conductivity of the lotus seed heart extract to be tested within the range of 1.5 mS / cm to 5.0 mS / cm; performing ultrasonic degassing and constant temperature treatment on the lotus seed heart extract to be tested before entering the flow detection cell, so that the real-time temperature deviation in the flow detection cell is controlled within 0.1℃, so as to eliminate the interference of temperature drift on molecular motion viscosity.

[0012] Preferably, step S103 includes: step S1031, using a coherent probe beam with a wavelength of 632.8nm to obliquely pass through the flow detection cell, and the polarization direction of the probe beam maintains a 45-degree angle with the electric field vector direction of the high-frequency bipolar symmetrical square wave electric field; the sampling frequency for recording transient birefringence attenuation trajectory data is set to 10MHz to 50MHz.

[0013] Preferably, step S104 further includes: step S1042, which involves associating and matching the determined rotational relaxation time constants with a preset rotational relaxation fingerprint library of lotus seed heart alkaloid standards. The fingerprint library covers standard relaxation parameters under different solvent ratios and temperature gradients, and the chemical classification of the target component is locked according to the principle of minimizing parameter deviation.

[0014] Preferably, step S102 further includes: step S1022, limiting the rise time and fall time of the high-frequency bipolar symmetrical square wave electric field to no more than 50 ns, so as to ensure that the steepness of the instantaneous fall edge after the electric field is removed meets the zero-time reference requirement for physical relaxation monitoring.

[0015] Preferably, step S104 further includes: step S1043, extracting the initial Kerr component amplitude corresponding to each exponential term in the transient birefringence attenuation trajectory data, using the linear proportional relationship between the initial Kerr component amplitude and the component molar concentration and optical anisotropy factor, and coupling with a preset response factor correction matrix to calculate the mass percentage content of each component.

[0016] Preferably, step S101 further includes: step S1012, selecting a flow test cell with a quartz optical window, the excitation electrode pair being composed of mutually parallel platinum electrode plates, and the physical distance between the two electrode plates being set to 1.0 mm to 3.0 mm.

[0017] Preferably, a reference calibration step is performed before step S101: In step S100, a blank solvent matrix without lotus seed alkaloid is injected into the flow detection cell, and the system background birefringence signal value of the polarization optical detection path is collected and calibrated as the subtraction reference for subsequent test data.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. In the property analysis of lotus seed heart extract, relying on the correlation between molecular rotational Brownian motion and effective hydrodynamic radius, the component signals that originally overlapped in the steady-state spectrum were transferred to the time domain for analysis. By capturing the transient birefringence attenuation trajectory after the excitation field was removed, and utilizing the physical differences between the three-dimensional spatial conformation and hydrodynamic volume of homologous molecules such as lotusine and isolivineine, the rotational relaxation time constant with component specificity was extracted, thereby achieving physical decoupling of the target component in a mixed fluid without a physical separation interface.

[0020] 2. By utilizing the high-frequency polarity switching characteristics of the bipolar symmetrical square wave electric field, the overall displacement vector of free background ions in the extract is forcibly locked within the local oscillation range. This mechanism maintains the effective dipole orientation of alkaloid molecules while counteracting the charge directional migration effect in the sample system, avoiding bubbles and local refractive index gradient distortion caused by electrolysis side reactions or Joule heating, and ensuring the stability of the optical baseline and the reproducibility of test results in complex electrolyte matrices.

[0021] 3. By combining the anomalous dispersion phenomenon within a specific wavelength range, and by selecting the linearly polarized probe light at the edge of the characteristic absorption band of the corresponding bisbenzylisoquinoline skeleton, the birefringence resonance enhancement effect is triggered. This method induces the electro-optic response signal of the target molecule to be amplified by a magnitude, and suppresses the non-resonance background birefringence caused by non-target impurities such as polysaccharides below the signal noise baseline, thereby achieving the acquisition of high signal-to-noise ratio characteristic parameters in the unpurified turbid extract stock solution. Attached Figure Description

[0022] Figure 1 This is a flowchart of the analysis of lotus seed heart alkaloid components with rotational relaxation characteristics according to the present invention;

[0023] Figure 2 This is a logic diagram of the online sample preprocessing and flow monitoring field construction system of the present invention.

[0024] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0026] A test method for the property analysis of lotus seed heart extract, comprising:

[0027] Step S101: The lotus seed heart extract to be tested is continuously introduced into a flow detection cell equipped with a polarization optical detection path and an excitation electrode pair, so that the detection beam passes through the flow detection cell and a transient electrically induced birefringence monitoring field is established for the lotus seed heart extract to be tested; the lotus seed heart extract to be tested contains lotusine, isoligusine and methyl lotusine in a dissolved state.

[0028] Step S102: Apply a high-frequency bipolar symmetrical square wave electric field to the excitation electrode pair. Utilize the high-frequency polarity switching characteristics of the high-frequency bipolar symmetrical square wave electric field to restrict the displacement vector of free ions in the lotus seed extract to be tested within the local perturbation range, suppress the overall polarization interference generated by the electrolyte matrix, and use the electric field vector to induce the electric dipole orientation of bisbenzylisoquinoline alkaloid molecules in the lotus seed extract to be tested.

[0029] Step S103: After the bisbenzylisoquinoline alkaloid molecules reach a saturated orientation equilibrium state, the high-frequency bipolar symmetrical square wave electric field is removed, and the transient birefringence attenuation trajectory data of the lotus seed extract to be tested after the electric field disappears is monitored and recorded synchronously through the polarization optical detection path.

[0030] Step S104: Multi-exponential fitting identification is performed on the transient birefringence attenuation trajectory data to separate the rotational relaxation time constants belonging to different molecular particle size components. Based on the cubic monotonic mapping law between the rotational relaxation time constant and the effective hydrodynamic radius of the molecule, the component identification results and content analysis data of lotusine, isolivineine, and methyl lotusine in the lotus seed heart extract to be tested are determined by the rotational relaxation difference of each component on the time scale.

[0031] Preferably, step S102 includes: step S1021, controlling the frequency of the high-frequency bipolar symmetrical square wave electric field to be 100kHz to 500kHz, and the peak-to-peak value of the field strength to be 200V / cm to 800V / cm; the voltage integral value of the high-frequency bipolar symmetrical square wave electric field in one complete cycle is 0, which is used to maintain an electrically neutral environment on the surface of the excitation electrode pair, suppress the generation of electrolytic bubbles and refractive index gradient noise induced by Joule heating in the flow detection cell, so as to stabilize the detection baseline of the polarization optical detection path.

[0032] Preferably, step S104 includes: step S1041, which involves identifying the rotational relaxation time constant. Substitute into the following formula to determine the effective hydrodynamic radius of the molecule. : ,in, Let be the rotational relaxation time constant. Boltzmann's constant, The absolute temperature of the lotus seed heart extract to be tested. The dynamic viscosity of the lotus seed heart extract to be tested was determined; the effective hydrodynamic radius was determined by the difference in spatial conformational symmetry between lotusine and isoliensine. The minute difference, through the cubic sensitivity of rotational relaxation to the radius, completes the physical decoupling of the overlapping spectral signals of the same components on the time scale.

[0033] Preferably, step S101 includes: step S1011, controlling the conductivity of the lotus seed heart extract to be tested within the range of 1.5 mS / cm to 5.0 mS / cm; performing ultrasonic degassing and isothermal treatment on the lotus seed heart extract before it enters the flow detection cell, so that the real-time temperature deviation in the flow detection cell is controlled within 0.1 mS / cm. The temperature should be kept below 30°C to eliminate the interference of temperature drift on molecular kinematic viscosity.

[0034] Preferably, step S103 includes: step S1031, using a coherent probe beam with a wavelength of 632.8nm to obliquely pass through the flow detection cell, and the polarization direction of the probe beam maintains a 45-degree angle with the electric field vector direction of the high-frequency bipolar symmetrical square wave electric field; the sampling frequency for recording transient birefringence attenuation trajectory data is set to 10MHz to 50MHz.

[0035] Preferably, step S104 further includes: step S1042, which involves associating and matching the determined rotational relaxation time constants with a preset rotational relaxation fingerprint library of lotus seed heart alkaloid standards. The fingerprint library covers standard relaxation parameters under different solvent ratios and temperature gradients, and the chemical classification of the target component is locked according to the principle of minimizing parameter deviation.

[0036] Preferably, step S102 further includes: step S1022, limiting the rise time and fall time of the high-frequency bipolar symmetrical square wave electric field to no more than 50 ns, so as to ensure that the steepness of the instantaneous fall edge after the electric field is removed meets the zero-time reference requirement for physical relaxation monitoring.

[0037] Preferably, step S104 further includes: step S1043, extracting the initial Kerr component amplitude corresponding to each exponential term in the transient birefringence attenuation trajectory data, using the linear proportional relationship between the initial Kerr component amplitude and the component molar concentration and optical anisotropy factor, and coupling with a preset response factor correction matrix to calculate the mass percentage content of each component.

[0038] Preferably, step S101 further includes: step S1012, selecting a flow test cell with a quartz optical window, the excitation electrode pair being composed of mutually parallel platinum electrode plates, and the physical distance between the two electrode plates being set to 1.0 mm to 3.0 mm.

[0039] Preferably, a reference calibration step is performed before step S101: In step S100, a blank solvent matrix without lotus seed alkaloid is injected into the flow detection cell, and the system background birefringence signal value of the polarization optical detection path is collected and calibrated as the subtraction reference for subsequent test data.

[0040] Example 1: In the scenario of component analysis of lotus seed heart extract in a continuous flow state, when the online monitoring system faces overlapping optical absorption spectra of components with similar conjugated skeletons such as lotusine, isolivineine, and methyl lotusine in the extract, and interference from industrial matrix background noise, this test method continuously introduces the lotus seed heart extract to be tested into a flow detection cell equipped with a polarization optical detection path and an excitation electrode pair to establish a transient electrically induced birefringence monitoring field for the lotus seed heart extract to be tested. The conductivity of the lotus seed heart extract to be tested is maintained in the range of 1.5 mS / cm to 5.0 mS / cm through desalination treatment, and ultrasonic degassing and constant temperature control are performed before entering the flow detection cell to maintain the real-time temperature deviation in the flow detection cell within 0.1℃. A high-frequency bipolar symmetrical square wave electric field with a frequency of 100kHz to 500kHz and a peak-to-peak field strength of 200V / cm to 800V / cm is applied to the excitation electrode pair. The voltage of this high-frequency bipolar symmetrical square wave electric field within a complete cycle is utilized. The physical property of zero integral value maintains an electrically neutral environment on the surface of the excitation electrode pair, suppressing polarization interference from the electrolyte matrix in the lotus seed heart extract to be tested, avoiding electrolytic bubbles and refractive index gradient noise induced by Joule heating. At the same time, the electric field vector induces the electric dipole orientation of bisbenzylisoquinoline alkaloid molecules in the lotus seed heart extract to be tested, causing the extract system to produce an optical birefringence state. In this induced orientation process, the high-frequency electric field does not rely on the slow permanent dipole physical rotation of the entire molecule, but instead rapidly polarizes the free ion cloud around the alkaloid molecular skeleton, instantaneously establishing an induced dipole moment on a nanosecond timescale. Since the direction of this surface induced dipole moment can always be synchronously reversed with the direction of the applied instantaneous electric field, the torque generated by the interaction between the two is always greater than zero on the overall time average, thus overcoming the mechanical hysteresis effect caused by high-frequency reversal, and continuously driving the large mass alkaloid molecules to overcome thermal motion and achieve effective arrangement in an alternating field of 100kHz to 500kHz.

[0041] A coherent probe beam with a wavelength of 632.8 nm was passed through a flow detection cell. The polarization direction of the probe beam was set to form a 45-degree angle with the electric field vector direction of the high-frequency bipolar symmetric square wave electric field. After the bisbenzyloisoquinoline alkaloid molecules reached orientation equilibrium, the high-frequency bipolar symmetric square wave electric field was removed. The fall time of the edge of the high-frequency bipolar symmetric square wave electric field was limited to no more than 50 ns to provide a zero-time reference required for physical relaxation monitoring. Due to the loss of external field constraint, the bisbenzyloisoquinoline alkaloid molecules recovered their spatial isotropic distribution under the thermal collision of fluid molecules. Simultaneously, a photodetector unit with a sampling frequency of 10 MHz to 50 MHz was used to record the transient birefringence attenuation trajectory data of the transmitted light intensity signal from the moment the electric field disappeared. The acquired transient birefringence attenuation trajectory data was subjected to multi-exponential fitting to separate the rotational relaxation time constants belonging to different components. The identified rotational relaxation time constants were then... Substitute into the formula to determine the effective hydrodynamic radius of the molecule. : ,in, Let be the rotational relaxation time constant. Boltzmann's constant, The absolute temperature of the lotus seed heart extract to be tested. The value represents the dynamic viscosity of the lotus seed heart extract to be tested.

[0042] The effective hydrodynamic radius is derived from the slight difference in the spatial conformational symmetry between limonin and isolimonin. By exploiting the cubic sensitivity of rotational relaxation to the radius, the physical decoupling of overlapping spectral signals of homologous components is achieved on a time scale. The determined rotational relaxation time constants are matched with a pre-defined rotational relaxation fingerprint library of lotus seed alkaloid standards to pinpoint component affixes. The amplitude values ​​of the components corresponding to each exponential term in the transient birefringence decay trajectory data are extracted, and the mass percentage content of each component is calculated based on a pre-defined response factor matrix. This transforms the identification logic of steady-state spectral signals into a molecular rotational dynamics fingerprint characterization with deterministic physical meaning, eliminating baseline interference caused by electrode polarization in high-conductivity industrial environments. This enables real-time monitoring of the component content in the extract. The physical measurement basis for reproduction is as follows: the optical anisotropy factor is determined by independently testing purified lotusine, isolivineine, and methyl lotusine standard solutions at the same 632.8nm wavelength and preset temperature to obtain their Kerr constants. The test system stores a basic vector composed of the reciprocals of the optical anisotropy factors of the above three standards. The basic vector is multiplied by the instrument constant to construct a preset response factor correction matrix. During real-time measurement, this matrix is ​​used to perform a mathematical matrix multiplication operation with the extracted multi-exponential fitting component amplitude column vector. The result of the calculation is the mass percentage content of each of the three alkaloids.

[0043] Example 2: In the group identification scenario of lotus seed heart extract containing complex industrial matrix and high concentration of ion background noise, a verification experiment was established to determine the performance indicators of the test method. The test platform included a flow detection cell with parallel platinum electrode pairs and an effective optical path of 10 mm, and a photoelectric signal acquisition system with a sampling frequency set to 50 MHz. The test data came from the real-time signal collected by the physical experimental platform. Regarding the setting of the excitation signal intensity, it was determined that the peak-to-peak value of the electric field intensity is the dominant factor affecting the orientation free energy of alkaloid molecules and the electrolytic stability of the system. The technical trade-off point is that a lower field strength cannot overcome the thermal disorder energy level of fluid molecules, making the birefringence signal intensity insufficient to cover the background thermal noise; while an excessively high field strength will cause electrochemical reactions inside the fluid, inducing bubble generation and destroying the detection baseline. According to the established linear energy mapping rule, when the dynamic viscosity of the lotus seed heart extract to be tested is... In the range of 0.89 mPa·s to 1.2 mPa·s, in order to maintain a signal-to-noise ratio of no less than 30 dB and prevent visible bubbles from forming on the electrode surface, the peak-to-peak value of the electric field strength is limited to between 200 V / cm and 800 V / cm. For the sample liquid with a current conductivity of 2.5 mS / cm, the peak-to-peak value of the electric field strength is specifically determined to be 500 V / cm.

[0044] The sample groups were divided into: control group A, which used UV-Vis spectrophotometry for steady-state spectral fitting; control group B, which used a high-frequency bipolar symmetrical square wave electric field for excitation but removed the transient relaxation fitting step; control group C, which used a DC pulse electric field instead of the high-frequency bipolar symmetrical square wave electric field as the excitation source; and the sample group of this invention using the test method. To simulate the industrial electromagnetic environment and matrix interference of the extract, Gaussian white noise with a signal-to-noise ratio of 20dB was superimposed at the front end of the signal acquisition, and 50Hz power frequency interference harmonics were simulated. The original absorption spectrum of the lotus seed heart extract to be tested in control group A was obtained, showing that the absorbance curves of lotus seed heart alkaloid and isolienin overlapped at 282nm, with a peak position difference of less than 1.5nm. After the noise interference was injected, the group resolution accuracy dropped to below 65%. The sample group of this invention established a transient electrically induced birefringence monitoring field and recorded the transient birefringence attenuation trajectory data after the high-frequency bipolar symmetrical square wave electric field was removed. The original monitoring curve showed an exponential decay trend with high-frequency spikes and baseline drift.

[0045] By utilizing the zero-value characteristic of voltage integral of bipolar square waves to suppress electrolyte polarization, the drift of the detection baseline within 50 ms was reduced from 15.4% in the control group C to below 0.3%. Multi-exponential fitting identification was performed on the processed transient birefringence decay trajectory data to separate the rotational relaxation time constant. At temperature The dynamic viscosity is 298.15 K. Under the operating condition of 0.89 mPa·s, the sample group of the present invention identified two sets of characteristic time components, which are respectively Equal to 125.4 μs and The value is 148.7 μs, while the control group B cannot distinguish these two physically specific features from the aliased steady-state birefringence signal. Substituting the values ​​into the formula determines the effective hydrodynamic radius of the molecule. : ,in, Let be the rotational relaxation time constant. Boltzmann's constant, The absolute temperature of the lotus seed heart extract to be tested. The value represents the dynamic viscosity of the lotus seed heart extract to be tested.

[0046] Effective hydrodynamic radius of the lotus seed alkaloid component The effective hydrodynamic radius attributable to the isolithocarmine component is 0.62 nm. The value is 0.66 nm. Similarly, when the multi-exponential fitting residuals have not converged to the preset threshold, the system continues to extract the third set of feature time components. Equal to 182.3 μs, substituting this into the above mapping relationship, the effective hydrodynamic radius belonging to the methylnephrine component can be solved. The resolution was 0.71 nm. This is because the additional methyl group in the molecular structure of methylcaecin increases the overall steric hindrance, making its hydrodynamic radius larger than that of caecin and isolidin. Based on the rotational relaxation differences of each component over time, the group identification results of caecin, isolidin, and methylcaecin were determined. The final measured mass percentage data, compared with the standard values ​​of offline high-performance liquid chromatography (HPLC), maintained an absolute error within 0.5%, and the group identification accuracy remained stable above 98.5%. Gradient pressure testing was conducted on the peak-to-peak field strength, and non-… The linear performance inflection point occurs when the peak-to-peak field strength increases from 500V / cm to 800V / cm, resulting in a stronger signal amplitude. However, once the field strength exceeds 850V / cm, the local current density in the flow detection cell surges, increasing the frequency of bubble generation and causing the standard deviation of the detection baseline to increase from 0.05mV to 4.2mV. This experiment demonstrates, through the logic chain from the original interference signal to the accurate component output, that this testing method achieves physical decoupling of homologous substances through molecular dynamics parameters in an industrial high-conductivity environment, providing a physical measurement basis for the real-time monitoring of the component content of the extract.

[0047] Example 3: In an industrial analysis scenario involving 72-hour uninterrupted component monitoring of lotus seed heart extract in a continuously flowing state, the online monitoring system faces baseline quasi-static drift caused by the adsorption of trace components on the electrode surface and pump pulsation. This test method establishes a baseline adaptive compensation procedure and fitting algorithm path to ensure the long-term stability of the measurement results. At the initial stage of each measurement cycle, the test system collects a polarized light intensity reference sequence under no applied electric field. The sampling duration of this reference sequence is set to 5ms, covering 50 complete 50Hz power frequency interference cycles. The DC bias component of this sequence is extracted using a moving average filtering algorithm. A high-frequency bipolar symmetrical square wave electric field is applied, the frequency of which is determined based on the rotational diffusion coefficient distribution characteristics of the dibenzylisoquinoline alkaloid molecules in the lotus seed heart extract to be tested. Due to the rotational relaxation time constant of the target molecule at 298.15K... With the electric field frequency determined in the range of 100μs to 200μs and between 100kHz and 500kHz, the electric field polarity switching period is made shorter than the double layer establishment time of ions, taking advantage of the physical constraint that the charge migration rate of ions is slower than the high-frequency electric field switching speed.

[0048] After the electric field is removed, the photoelectric detection unit acquires transient birefringence attenuation trajectory data with a length of 1 ms and stores it in a discrete time series array with a step size of 20 ns. The multi-exponential fitting identification process for this trajectory data is implemented according to programmed steps. The initial slope of the attenuation trajectory is identified using differential transformation. If the absolute value of the initial slope is greater than a preset background noise threshold, the current data packet is determined to be valid. An iterative decoupling logic based on nonlinear least squares is used to decompose the discrete time series into the sum of multiple exponential attenuation terms. Finally, the number of each exponential term is determined by the residual energy minimization criterion. Iteration stops when the residual value converges to less than 0.5% of the peak value of the original signal. The fitted rotational relaxation time constants are then used to identify the attenuation trajectory. The system matches the measured rotational relaxation time constant with a pre-defined rotational relaxation fingerprint library of lotus seed alkaloid standards. It then retrieves the time constant sequences of standards stored in the library under the same temperature and viscosity conditions, and calculates the measured rotational relaxation time constant. The Euclidean distance from the reference values ​​of each standard component in the library is used. When the minimum Euclidean distance is less than 2% of the reference value, the chemical assignment is locked, and the identified 125.4 μs component is assigned to lotus seed alkaloid. The calculated effective hydrodynamic radius is then used as a reference. If the deviation from the fingerprint database value exceeds 5%, the system automatically initiates the baseline adaptive compensation procedure, based on the real-time conductivity measurement value of the current flow detection cell. Introducing correction factors : ,in, As a correction factor, This is a reference value for conductivity under standard conditions. The real-time conductivity measurement value of the lotus seed heart extract to be tested is used to compare the real-time measurement value with the correction factor. The multiplication process corrects the physical parameters and re-matches the fingerprint. During the execution of the above correction logic, the real-time measured value specifically points to the original rotational relaxation time constant of the system's fitted output. Correction factor The original time constant is multiplied by the time constant, and the corrected time parameter is used to counteract the masking interference of the electrolyte matrix ionic strength change on the overall fluid viscosity.

[0049] After 72 hours of continuous operation, this procedure maintained the system's group resolution drift within 0.2%. By coupling molecular motion mechanisms with real-time operating condition compensation, the system maintained the analytical accuracy of lotusine, isolivineine, and methyl lotusine components under complex production environments, achieving closed-loop processing from initial signal fluctuations to stable technical indicator output. Addressing the reality of sample solution viscosity fluctuations with solvent ratios in the production process, a multi-sensor fusion-based online compensation procedure was implemented, establishing a transient electro-induced birefringence monitoring field and acquiring real-time sample solution conductivity values ​​through a conductivity sensor. The sampling frequency is 100Hz, combined with real-time temperature. The system retrieves a viscosity benchmark table, which covers viscosity gradient data within the ethanol content range of 30% to 90%, and determines the dynamic viscosity using a linear interpolation algorithm. The parameter is fed back to the rotational relaxation time constant analysis logic. Measurement drift caused by external environmental disturbances and batch differences is converted into a compensation factor to improve the reliability of the extracted rotational relaxation feature parameters matching the standard rotational relaxation fingerprint database. The matching process follows the Euclidean distance minimization criterion. When the deviation between the measured parameters and the standard components in the fingerprint database is within the 2% tolerance range, the chemical attribution is locked. Molecular dynamics information is converted into a neutral mass percentage content index. The original sampling data involving specific process batches are minimized and desensitized. The flow detection cell uses a quartz optical window with a light-transmitting aperture of 3mm to 5mm, matched with a linearly polarized probe beam with a wavelength of 632.8nm. The excitation electrode pair is made of platinum, and the electrode surface is electrochemically polished to eliminate local micro-field distortion. The system has a built-in birefringence signal value based on the system background. The adaptive cleaning procedure automatically switches the flow path when the background noise variance exceeds a preset threshold of 0.5mV. It then guides a 10% dilute nitric acid solution to circulate and rinse the flow detection cell at a flow rate of 2.0mL / min for 5 minutes, before switching to deionized water to rinse until neutral, restoring the initial impedance state and optical baseline of the electrode system. To address the synchronization accuracy requirements between the removal of the high-frequency bipolar symmetrical square wave electric field and the start of signal recording, this test method uses an edge logic triggering procedure to determine the sampling zero point. During the excitation of the monitoring field, the photoelectric detection unit with a sampling frequency of 50MHz is kept in a cyclic buffer state. A TTL logic pulse is generated by identifying the voltage falling edge signal at the output of the electrode drive circuit. This TTL logic pulse is used to lock the starting point of the discrete time sequence of the transient birefringence attenuation trajectory data, thereby compensating for the nanosecond-level clock deviation induced by circuit switching on the rotational relaxation time constant. The physical effects of extraction accuracy.

[0050] Example 4: In an engineering scenario where flow detection cells are deployed for different production batches, when the surface state of the excitation electrode pair experiences initial impedance differences due to storage time, this test method applies an electrode surface normalization calibration procedure to maintain the stability of the measurement benchmark. Specifically, high-purity deionized water is introduced into the flow detection cell, and the ambient temperature is kept constant at 298.15K. A detection electric field with a frequency of 500kHz and a peak-to-peak value of 200V / cm is applied to the excitation electrode pair. A photoelectric detection unit monitors fluctuations in transmitted light intensity and calculates the noise variance of the current electrode system. If the variance value is greater than the preset background light intensity threshold, the flow detection cell is circulated and rinsed with a 10% dilute nitric acid solution until the noise variance obtained from three consecutive monitoring tests is less than 0.1% of the signal resolution.

[0051] When the solvent system of the extract experiences shifts in medium polarity and dynamic viscosity due to adjustments in the alcohol-to-water ratio, this test method employs a fingerprint database parameter reconstruction procedure to address the nonlinear changes in the rotational Brownian motion damping characteristics. The test system utilizes an integrated conductivity sensor to acquire real-time conductivity measurements of the lotus seed heart extract under test. And compare it with the reference conductivity corresponding to the standard fingerprint database. By comparing the results, the environmental correction operator is determined based on the monotonic mapping relationship between solvent kinetic viscosity and solvent composition. This allows the reference value of the rotational relaxation time constant stored in the fingerprint database to be used. Updated to the corrected rotational relaxation time constant The specific calculation formula is as follows: ,in, This is the corrected rotational relaxation time constant. The reference value for the rotational relaxation time constant is... An environmental correction operator is used; by matching transient birefringence attenuation trajectory data under different alcohol-water ratios using an updated fingerprint database, the group identification results maintain physical consistency when solvent composition changes; in the continuous processing scenario of lotus seed heart extract with high-concentration ion background, when the sample conductivity exceeds 5.0 mS / cm, causing an increase in electrode polarization noise, this test method applies an online ion intensity adjustment procedure to determine the state of the injected components. That is, by controlling the linear velocity of the extract flowing through the ion exchange medium layer to adjust the concentration of charged particles, and simultaneously using an ultrasonic degassing component to perform cavitation treatment at a frequency of 40 kHz to remove dissolved gases, until the real-time measurement value output by the integrated conductivity sensor is obtained. Until it falls within the preset monitoring range of 1.5 mS / cm to 5.0 mS / cm.

[0052] Example 5: In a deployment scenario for sensitivity calibration of a flow detection cell, when the system faces the influence of non-uniform monitoring field caused by slight installation differences of the excitation electrodes, this test method uses a geometric field strength calibration procedure to determine the electrode gap. By guiding the standard refractive index matching liquid into the flow detection cell and ensuring the probe beam passes through the geometric center of the cell, the peak-to-peak value of the electric field is adjusted stepwise within the range of 200V / cm to 800V / cm. The static birefringence phase retardation is recorded, and the linear regression residual between this phase retardation and the square of the electric field is calculated. If the residual value exceeds 1%, the electrode gap is adjusted. The accuracy is reduced to 2.0 mm, thereby reducing the spatial deviation of the electric field vector within the detection area to less than 0.5%.

[0053] When the dynamic viscosity of the lotus seed heart extract to be tested changes due to fluctuations in ambient temperature, this test method uses the excitation pulse width determination procedure to determine the duration of the high-frequency bipolar symmetrical square wave electric field. The test system initiates a pre-detection cycle to monitor the change curve of the first derivative of transmitted light intensity over time. When this derivative value remains below a preset equilibrium threshold for 10 μs, the corresponding time coordinate is determined, and a 20% redundancy is added as the duration. This allows bisbenzylisoquinoline alkaloid molecules to reach an orientation equilibrium state before the electric field is removed. The amplitude of the unloaded response is used as the benchmark for minimizing the residual energy in the multi-exponential fitting identification algorithm, utilizing the system calibration time constant offset. Corrected rotational relaxation time constant The specific calculation formula is as follows: ,in, This is the corrected rotational relaxation time constant. To identify the original rotational relaxation time constant, The time constant offset of the system is calibrated; the rotational relaxation fingerprint library of lotus seed heart alkaloid standard is matched with the corrected physical parameters to ensure that the group identification results maintain the consistency of the values ​​after component replacement.

[0054] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A test method for the property analysis of lotus seed heart extract, characterized in that, include: Step S101: The lotus seed heart extract to be tested is continuously introduced into a flow detection cell equipped with a polarization optical detection path and an excitation electrode pair, so that the detection beam passes through the flow detection cell and a transient electrically induced birefringence monitoring field is established for the lotus seed heart extract to be tested; the lotus seed heart extract to be tested contains lotusine, isoligusine and methyl lotusine in a dissolved state. Step S102: Apply a high-frequency bipolar symmetrical square wave electric field to the excitation electrode pair. Utilize the high-frequency polarity switching characteristics of the high-frequency bipolar symmetrical square wave electric field to restrict the displacement vector of free ions in the lotus seed extract to be tested within the local perturbation range, suppress the overall polarization interference generated by the electrolyte matrix, and use the electric field vector to induce the electric dipole orientation of bisbenzylisoquinoline alkaloid molecules in the lotus seed extract to be tested. Step S103: After the bisbenzylisoquinoline alkaloid molecules reach a saturated orientation equilibrium state, the high-frequency bipolar symmetrical square wave electric field is removed, and the transient birefringence attenuation trajectory data of the lotus seed extract to be tested after the electric field disappears is monitored and recorded synchronously through the polarization optical detection path. Step S104: Multi-exponential fitting identification is performed on the transient birefringence attenuation trajectory data to separate the rotational relaxation time constants belonging to different molecular particle size components. Based on the cubic monotonic mapping law between the rotational relaxation time constant and the effective hydrodynamic radius of the molecule, the component identification results and content analysis data of lotusine, isolivineine, and methyl lotusine in the lotus seed heart extract to be tested are determined by the rotational relaxation difference of each component on the time scale.

2. The test method for property analysis of lotus seed heart extract according to claim 1, characterized in that, Step S102 includes: Step S1021, controlling the frequency of the high-frequency bipolar symmetrical square wave electric field to be from 100kHz to 500kHz, and the peak-to-peak value of the field strength to be from 200V / cm to 800V / cm; the voltage integral value of the high-frequency bipolar symmetrical square wave electric field in one complete cycle is 0, which is used to maintain an electrically neutral environment on the surface of the excitation electrode pair, suppress the generation of electrolytic bubbles and refractive index gradient noise induced by Joule heating in the flow detection cell, so as to stabilize the detection baseline of the polarization optical detection path.

3. The test method for property analysis of lotus seed heart extract according to claim 1, characterized in that, Step S101 includes: Step S1011, controlling the conductivity of the lotus seed heart extract to be tested within the range of 1.5 mS / cm to 5.0 mS / cm; performing ultrasonic degassing and constant temperature treatment on the lotus seed heart extract to be tested before entering the flow detection cell, so that the real-time temperature deviation in the flow detection cell is controlled within 0.1℃, so as to eliminate the interference of temperature drift on molecular motion viscosity.

4. The test method for property analysis of lotus seed heart extract according to claim 1, characterized in that, Step S103 includes: Step S1031, using a coherent probe beam with a wavelength of 632.8nm to obliquely pass through the flow detection cell, and the polarization direction of the probe beam maintains a 45-degree angle with the electric field vector direction of the high-frequency bipolar symmetrical square wave electric field; the sampling frequency for recording transient birefringence attenuation trajectory data is set to 10MHz to 50MHz.

5. The test method for property analysis of lotus seed heart extract according to claim 1, characterized in that, Step S104 further includes: Step S1042, which involves associating and matching the determined rotational relaxation time constants with the preset rotational relaxation fingerprint library of lotus seed heart alkaloid standards. The fingerprint library covers standard relaxation parameters under different solvent ratios and temperature gradients, and the chemical assignment of the target component is locked according to the principle of minimizing parameter deviation.

6. The test method for property analysis of lotus seed heart extract according to claim 2, characterized in that, Step S102 further includes: Step S1022, which limits the rise time and fall time of the high-frequency bipolar symmetrical square wave electric field to no more than 50 ns, so as to ensure that the steepness of the instantaneous fall edge after the electric field is removed meets the zero-time reference requirement for physical relaxation monitoring.

7. The test method for property analysis of lotus seed heart extract according to claim 1, characterized in that, Step S104 further includes: Step S1043, extracting the initial Kerr component amplitude corresponding to each exponential term in the transient birefringence attenuation trajectory data, using the linear proportional relationship between the initial Kerr component amplitude and the component molar concentration and optical anisotropy factor, and coupling with a preset response factor correction matrix to calculate the mass percentage content of each component.

8. The test method for property analysis of lotus seed heart extract according to claim 1, characterized in that, Step S101 further includes: Step S1012, selecting a flow test cell with a quartz optical window, the excitation electrode pair being composed of mutually parallel platinum electrode plates, and the physical distance between the two electrode plates being set to 1.0 mm to 3.0 mm.

9. The test method for property analysis of lotus seed heart extract according to claim 1, characterized in that, Before step S101, a reference calibration step is performed: In step S100, a blank solvent matrix without lotus seed alkaloid is injected into the flow detection cell, and the system background birefringence signal value of the polarization optical detection path is collected and calibrated as the subtraction reference for subsequent test data.

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