Method for detecting monomer nitrogen-hydrogen-chlorine multi-dimensional stable isotope of chloroaniline and method for monitoring chloroaniline

Abstract

The invention provides a detection method of a monomer nitrogen-hydrogen-chlorine multidimensional stable isotope of chloroaniline and a monitoring method of chloroaniline, and relates to the technical field of isotope detection. According to the method, a gas phase-double oxidation tube-stable isotope ratio mass spectrum is adopted to detect and calculate a nitrogen stable isotope ratio in chloroaniline, and a gas phase-chromium filler cracking tube-stable isotope ratio mass spectrum is adopted to detect and calculate a hydrogen stable isotope ratio; the gas phase-multi-collector inductively coupled plasma mass spectrometry is adopted to detect and calculate the chlorine stable isotope ratio, so that the determination of the multi-element stable isotope ratio of nitrogen, hydrogen and chlorine in o-chloroaniline, m-chloroaniline and parachloroaniline is realized, the detection degree is more comprehensive, and the detection result is accurate, efficient and reliable. The range of each isotope signal value in the detection process is controlled, and high accuracy of the detection result can be ensured. The detection method provided by the invention provides a new method and means for deep research and monitoring of chloroaniline traceability, degradation mechanism and environmental homing.

Description

Technical Field

[0001] The invention relates to the technical field of isotope detection, and in particular to a method for detecting monomeric nitrogen, hydrogen and chlorine multi-dimensional stable isotopes of chloroaniline and a method for monitoring chloroaniline. Background Art

[0002] Chloroaniline is widely used in the industrial production of dyes, cosmetics, pharmaceuticals and herbicides. It is also a secondary transformation product of the non-ferrous metal sulfide ore collector aniline black medicine. Chloroaniline has a certain persistence in the environment, accumulates in industrial wastewater, sludge, agricultural soil and sediments, and is widely detected in the environment. Chloroaniline (o-chloroaniline, m-chloroaniline and p-chloroaniline) is highly toxic and difficult to degrade to aquatic organisms. There is an urgent need to study the transformation mechanism of chloroaniline and explore its migration and transformation in the environment and its environmental fate, so as to better control it and reduce pollution.

[0003] The application of single isotope analysis (CSIA) in the degradation evaluation of environmental organic pollutants has gradually become a research hotspot. It can not only be used to identify and analyze the source of pollutants, evaluate degradation transformation and degradation mechanism, but also be applied to the field biodegradation and chemical degradation of pollutants. CSIA measures the stable isotope ratio of specific elements in a single compound, and its results are not interfered by other reactants, products and elements, thus improving the reliability and accuracy of the test results. In terms of experimental technology, CSIA can not only quantitatively study the transformation process of organic pollutants in the environment, but also clarify the mechanism of the transformation process. It has been widely used in environmental chemistry, geochemistry and other fields.

[0004] CSIA monitors the transformation process of organic pollutants in time and space by analyzing the stable isotope ratios of specific elements in organic pollutants. The principle is that the bond breaking reactions between isotopologues follow different kinetics due to the rate limitation of the transition state caused by the different isotope masses, which is usually called the kinetic isotope effect (KIE). 2 H. 13 C. 15 N or 37 Cl) reacts faster than the corresponding light isotopologue (e.g. 1 H. 12 C. 13 N or 35Normal KIE is observed when the reaction rate is slow, resulting in the enrichment of heavier isotopologues in the unconverted reactant fraction, and is often detected in biological or chemical bond breaking reactions. Conversely, reverse kinetic isotope effects are observed when heavier isotopologues react preferentially and thus result in the enrichment of lighter isotopologues in the unconverted reactant fraction. These effects can be used as indicators of complex transition states with multiple rate limitations. Because CSIA is able to detect the effects of specific reactions, it can provide direct evidence for the transformation of pollutants and may provide insight into transformation pathways without determining the transformation products (TPs) through product analysis.

[0005] At present, there are reports on the carbon and nitrogen isotope fractionation and reaction mechanism of chloroaniline in the direct photodegradation process by CSIA. This method can be used to determine o-chloroaniline (2-CA), m-chloroaniline (3-CA) and p-chloroaniline (4-CA). However, since the application of CSIA technology in environmental determination is affected by various factors (instrument accuracy, precision, isotope reference standards, oxidation efficiency, etc.), the existing conventional CSIA method for multi-element monomer carbon stable isotope analysis of chloroaniline is not perfect and cannot simultaneously meet the multi-dimensional isotope determination of hydrogen, nitrogen and chlorine in chloroaniline. Summary of the invention

[0006] In view of this, the object of the present invention is to provide a method for detecting the multi-dimensional stable isotopes of nitrogen, hydrogen and chlorine in chloroaniline and a method for monitoring chloroaniline. The detection method provided by the present invention can detect the stable isotope ratios of nitrogen, hydrogen and chlorine in o-chloroaniline, m-chloroaniline or p-chloroaniline, and the detection results are accurate, efficient and reliable.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for detecting monomer nitrogen, hydrogen and chlorine multi-dimensional stable isotopes of chloroaniline, comprising the following steps:

[0009] The organic solution of chloroaniline is subjected to gas chromatography separation, and then subjected to dual oxidation tube-isotope ratio mass spectrometry detection, chromium filler pyrolysis tube-isotope ratio mass spectrometry detection and multi-collector inductively coupled plasma mass spectrometry detection, respectively, to obtain detection results of stable isotope ratios of nitrogen, hydrogen and chlorine;

[0010] The chloroaniline includes o-chloroaniline, m-chloroaniline or p-chloroaniline;

[0011] During the double oxidation tube-isotope ratio mass spectrometry detection process, the nitrogen isotope signal value of o-chloroaniline is greater than 0.2V, the nitrogen isotope signal value of m-chloroaniline is greater than 0.1V, and the nitrogen isotope signal value of p-chloroaniline is greater than 0.2V;

[0012] During the chromium packing pyrolysis tube-isotope ratio mass spectrometry detection process, the hydrogen isotope signal value of o-chloroaniline is greater than 1.5V, the hydrogen isotope signal value of m-chloroaniline is greater than 0.5V, and the hydrogen isotope signal value of p-chloroaniline is greater than 0.5V;

[0013] In the multi-collector inductively coupled plasma mass spectrometry detection process, the chlorine isotope signal value of o-chloroaniline is greater than 4V, the chlorine isotope signal value of m-chloroaniline is greater than 2.5V, and the chlorine isotope signal value of p-chloroaniline is greater than 1V.

[0014] Preferably, the conditions for gas chromatography separation include: the chromatographic column includes a (5%-phenyl)-methylpolysiloxane capillary column, the injection mode is a fractionation mode, the fractionation ratio is 1:2-5, the injection volume is 1-5 μL, the injection port temperature is 220-260°C, the helium flow rate is 1.5 mL / min, and the heating program is: the initial temperature is maintained at 60°C for 2 minutes, the temperature is increased to 180°C at a rate of 15°C / min and maintained for 2 minutes, and the temperature is increased to 290°C at a rate of 15°C / min and maintained for 5 minutes.

[0015] Preferably, the conditions for the dual oxidation tube-isotope ratio mass spectrometry detection include: the dual oxidation tubes are two oxidation tubes connected in series, and the temperatures of the two oxidation tubes connected in series are 1000° C. and 600° C. respectively.

[0016] Preferably, the conditions for the chromium-filled pyrolysis tube-isotope ratio mass spectrometry detection include: the temperature of the chromium-filled pyrolysis tube is 1200°C.

[0017] Preferably, the conditions for the multi-collector inductively coupled plasma mass spectrometry detection include: operating in a low-resolution mode, wherein the low-resolution mode is m / Δm=400.

[0018] Preferably, the oxidation tube includes a ceramic tube and a mixture of NiO and CuO filled in the ceramic tube.

[0019] Preferably, the chromium-filled pyrolysis tube used in the chromium-filled pyrolysis tube-isotope ratio mass spectrometry detection comprises a high-temperature pyrolysis tube with openings at both ends and chromium powder filled in the high-temperature pyrolysis tube, and the two ends of the chromium powder are blocked with quartz wool.

[0020] Preferably, the gas chromatograph is connected to the multi-collector inductively coupled plasma mass spectrometer via a heated transmission line, and the temperature of the heated transmission line is 250°C.

[0021] Preferably, the organic solvent in the organic solution of chloroaniline includes at least one of dichloromethane and n-hexane.

[0022] The present invention also provides a monitoring method for chloroaniline, comprising the following steps:

[0023] Obtain the detection results of the stable isotope ratios of nitrogen, hydrogen and chlorine of chloroaniline according to the detection method described in the above technical scheme;

[0024] The monitoring results of chloroaniline are obtained according to the detection results; the monitoring results include one or more of the following: source tracing, degradation mechanism and environmental fate.

[0025] The present invention adopts gas phase-dual oxidation tube-stable isotope ratio mass spectrometry (GC-CC-IRMS) to detect and calculate the nitrogen stable isotope ratio in chloroaniline, adopts gas phase-chromium packing cracking tube-stable isotope ratio mass spectrometry (GC-HTC(Cr)-IRMS) to detect and calculate the hydrogen stable isotope ratio, and adopts gas phase-multi-collector inductively coupled plasma mass spectrometry (GC-MC-ICPMS) to detect and calculate the chlorine stable isotope ratio. The detection method provided by the present invention is applicable to the determination of the multi-element stable isotope ratio of nitrogen, hydrogen and chlorine in o-chloroaniline, m-chloroaniline and p-chloroaniline, and can realize the effective separation between the analyte and the matrix interference. Compared with the existing conventional CSIA detection method, the multi-element stable isotope ratio determination has a more comprehensive detection degree, and the detection result is accurate, efficient and reliable. The detection method provided by the present invention provides a new method and means for the in-depth study and monitoring of the source tracing, degradation mechanism and environmental fate of chloroaniline. The invention can ensure high accuracy of the detection result by controlling the range of the isotope signal value in each chloroaniline during the detection process.

[0026] In the process of detecting the nitrogen stable isotope ratio, the present invention can eliminate the influence of impurities in the sample by superimposing oxidation tubes (connecting two oxidation tubes in series), and the nitrogen stable isotope ratio detection result has high accuracy.

[0027] The present invention performs chromium modification on a high temperature cracking tube (HTC) and adopts a chromium filled cracking tube (HTC (Cr)) for cracking reaction, thereby eliminating the influence of impurities in the sample and achieving high accuracy in the detection result of the hydrogen stable isotope ratio. Moreover, the chromium powder can absorb the HCl formed by the reaction, thereby preventing the HCl gas from damaging the high temperature cracking tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The schematic diagram of the instrument structure of gas phase-chromium packed pyrolysis tube-stable isotope ratio mass spectrometry (GC-HTC(Cr)-IRMS);

[0029] Figure 2 Schematic diagram of the instrument structure of gas phase-multi-collector inductively coupled plasma mass spectrometry (GC-MC-ICPMS);

[0030] Figure 3 This is the nitrogen stable isotope spectrum of o-chloroaniline;

[0031] Figure 4is the hydrogen stable isotope spectrum of o-chloroaniline;

[0032] Figure 5 is the chlorine stable isotope spectrum of o-chloroaniline;

[0033] Figure 6 is the δ of o-chloroaniline at different signal values 15 N value (a), δ 2 H value (b), δ 37 Amplitude value diagram of Cl value (c);

[0034] Figure 7 This is the nitrogen stable isotope spectrum of m-chloroaniline;

[0035] Figure 8 This is the hydrogen stable isotope spectrum of m-chloroaniline;

[0036] Fig. 9 is the chlorine stable isotope spectrum of m-chloroaniline;

[0037] Fig.10 is the δ of m-chloroaniline at different signal values 15 N value (a), δ 2 H value (b), δ 37 Amplitude value diagram of Cl value (c);

[0038] Fig.11 is the nitrogen stable isotope spectrum of p-chloroaniline;

[0039] Fig.12 is the hydrogen stable isotope spectrum of p-chloroaniline;

[0040] Fig.13 is the chlorine stable isotope spectrum of p-chloroaniline;

[0041] Fig.14 is the δ of p-chloroaniline at different signal values 15 N value (a), δ 2 H value (b), δ 37 Amplitude value diagram of Cl value (c). DETAILED DESCRIPTION

[0042] The present invention provides a method for detecting monomer nitrogen, hydrogen and chlorine multi-dimensional stable isotopes of chloroaniline, comprising the following steps:

[0043] The organic solution of chloroaniline is subjected to gas chromatography separation, and then subjected to dual oxidation tube-isotope ratio mass spectrometry detection, chromium filler pyrolysis tube-isotope ratio mass spectrometry detection and multi-collector inductively coupled plasma mass spectrometry detection, respectively, to obtain detection results of stable isotope ratios of nitrogen, hydrogen and chlorine;

[0044] The chloroaniline includes o-chloroaniline, m-chloroaniline or p-chloroaniline;

[0045] During the double oxidation tube-isotope ratio mass spectrometry detection process, the nitrogen isotope signal value of o-chloroaniline is greater than 0.2V, the nitrogen isotope signal value of m-chloroaniline is greater than 0.1V, and the nitrogen isotope signal value of p-chloroaniline is greater than 0.2V;

[0046] During the chromium packing pyrolysis tube-isotope ratio mass spectrometry detection process, the hydrogen isotope signal value of o-chloroaniline is greater than 1.5V, the hydrogen isotope signal value of m-chloroaniline is greater than 0.5V, and the hydrogen isotope signal value of p-chloroaniline is greater than 0.5V;

[0047] In the multi-collector inductively coupled plasma mass spectrometry detection process, the chlorine isotope signal value of o-chloroaniline is greater than 4V, the chlorine isotope signal value of m-chloroaniline is greater than 2.5V, and the chlorine isotope signal value of p-chloroaniline is greater than 1V.

[0048] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0049] In the present invention, the conditions for gas chromatography separation preferably include: the chromatographic column includes a (5%-phenyl)-methyl polysiloxane capillary column, which can be a BPX-5 capillary column (size: 60m×0.25mm×0.25μm) in a specific embodiment; the injection mode is a fractionation mode; the fractionation ratio is 1:2-5, which can be 1:2, 1:3, 1:4 or 1:5 in a specific embodiment; the injection volume is 1-5μL, which can be 1μL in a specific embodiment. L, 2μL, 3μL, 4μL or 5μL; the injection port temperature is 220-260°C, and in specific embodiments can be 220°C, 230°C, 240°C, 250°C or 260°C; the helium flow rate is 1.5mL / min, and the heating program is: the initial temperature is maintained at 60°C for 2min, heated to 180°C at a rate of 15°C / min and maintained for 2min, heated to 290°C at a rate of 15°C / min and maintained for 5min.

[0050] In the present invention, the conditions of the dual oxidation tube-isotope ratio mass spectrometry detection preferably include: the dual oxidation tube is two oxidation tubes connected in series, and the temperatures of the two oxidation tubes in series are 1000°C and 600°C respectively. In the present invention, the oxidation tube is preferably oxidized before use. The present invention has no special limitation on the oxidation, as long as all the carbon in the chloroaniline can be oxidized to carbon dioxide. In the present invention, the oxidation tube includes a ceramic tube and a mixture of NiO and CuO filled in the ceramic tube. The present invention can eliminate the influence of impurities in the sample by superimposing the oxidation tubes, and the nitrogen stable isotope ratio detection result has high accuracy.

[0051] In the present invention, the conditions for the chromium-filled cracking tube-isotope ratio mass spectrometry detection preferably include: the temperature of the chromium-filled cracking tube is 1200°C. In the present invention, the chromium-filled cracking tube used for the chromium-filled cracking tube-isotope ratio mass spectrometry detection preferably includes a high-temperature cracking tube with two ends open and chromium powder filled in the high-temperature cracking tube, and the two ends of the chromium powder are blocked with quartz wool. In the present invention, the high-temperature cracking tube is preferably purchased from friatec, Germany, and chromium powder is filled in the high-temperature cracking tube, and quartz wool is used to block the two ends of the chromium powder. In the present invention, the chromium powder is preferably micron-level, more preferably 250-300μm. The present invention can eliminate the influence of impurities in the sample by modifying the high-temperature cracking tube (HTC) with chromium and using HTC (Cr) for cracking reaction, and the hydrogen stable isotope ratio detection result has high accuracy. Moreover, the chromium powder can absorb the HCl formed by the reaction to prevent HCl gas from damaging the high-temperature cracking tube.

[0052] In the present invention, the conditions for the multi-collector inductively coupled plasma mass spectrometry detection preferably include: operating in a low-resolution mode, wherein the low-resolution mode is m / Δm=400, and the instrument used is preferably Neptune. In the present invention, the gas chromatograph (GC) and the multi-collector inductively coupled plasma mass spectrometer (MC-ICPMS) are preferably connected via a heated transmission line (see Figure 2 ).

[0053] In the present invention, the organic solvent (referred to as the first organic solvent) in the organic solution of chloroaniline includes at least one of dichloromethane and n-hexane. The present invention has no special limitation on the concentration of chloroaniline in the organic solution of chloroaniline, as long as the signal value of each isotope in the detection process of chloroaniline can meet the above requirements.

[0054] In the present invention, the method for preparing the organic solution of chloroaniline preferably comprises the following steps: dissolving chloroaniline in acetone to obtain a chloroaniline mother liquor; diluting the chloroaniline mother liquor with water to obtain a chloroaniline dilution; performing liquid-liquid extraction on the chloroaniline dilution with a first organic solvent, and the organic layer is an organic solution of chloroaniline. In the present invention, the concentration of the chloroaniline mother liquor is preferably 2 to 10 g / L, and in a specific embodiment, it can be 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L or 10 g / L. In the present invention, the temperature of the liquid-liquid extraction is preferably 6 to 8 ° C, and in a specific embodiment, it can be 6 ° C, 7 ° C or 8 ° C; the time of the liquid-liquid extraction is preferably 4 to 6 h, and in a specific embodiment, it can be 4 h, 5 h or 6 h; the liquid-liquid extraction is preferably carried out under shaking conditions on a shaker. The present invention has no special limitation on the dilution multiple, as long as the signal value of each isotope in the detection process of the prepared chloroaniline organic solution meets the above requirements.

[0055] The present invention uses o-chloroaniline, m-chloroaniline and p-chloroaniline as target pollutants to explore the differences and rules of the nitrogen, hydrogen and chlorine isotope values ​​at the three substituent positions. The target is transferred from the aqueous phase to the organic phase for determination by liquid-liquid extraction. The treatment method is simple and easy to operate, and will not produce fractionation effects, ensuring that the stable isotope values ​​of the samples remain consistent before and after pretreatment, and the detection results are highly accurate.

[0056] In the present invention, each sample is preferably repeated 3 times during the detection process to ensure the reproducibility of the detection results; during the detection process, the standard deviation of the stable isotope ratios of nitrogen, hydrogen and chlorine preferably satisfies δ 13 N: ±0.3‰, δ 2 H: ±5‰; δ 37 Cl: ±0.5‰.

[0057] The present invention adopts gas phase-double oxidation tube-stable isotope ratio mass spectrometry (GC-CC-IRMS) to detect and calculate the nitrogen stable isotope ratio in chloroaniline, and adopts gas phase-chromium packing pyrolysis tube-stable isotope ratio mass spectrometry (GC-HTC(Cr)-IRMS, see Figure 1 , HTC(Cr) is located in IsoLink) to detect and calculate the hydrogen stable isotope ratio, and gas phase-multi-collector inductively coupled plasma mass spectrometry (GC-MC-ICPMS, see Figure 2) detects and calculates the chlorine stable isotope ratio. The detection method provided by the present invention is applicable to the determination of the multi-element stable isotope ratios of nitrogen, hydrogen and chlorine in o-chloroaniline, m-chloroaniline and p-chloroaniline, and can achieve the separation between the analyte and the matrix interference. Compared with the existing conventional CSIA detection method, the multi-element stable isotope ratio determination method provided by the present invention has a more comprehensive detection degree, and the detection result is accurate, efficient and reliable. Moreover, the present invention further eliminates the influence of impurities in the sample by superimposing the use of oxidation tubes and the chromium modification of HTC, thereby enhancing the accuracy of the test results. The detection method provided by the present invention provides new methods and means for in-depth research and monitoring of the source tracing, degradation mechanism and environmental fate of chloroaniline. The present invention can ensure the high accuracy of the detection result by controlling the range of each isotope signal value in each chloroaniline during the detection process.

[0058] The present invention also provides a chloroaniline monitoring method comprising the following steps: obtaining the detection results of the stable isotope ratios of nitrogen, hydrogen and chlorine of chloroaniline according to the detection method described in the above technical solution; obtaining the monitoring results of chloroaniline according to the detection results; the monitoring results include one or more of tracing the source, degradation mechanism and environmental fate. The present invention has no special limitation on the specific conversion process of obtaining the monitoring results of chloroaniline according to the detection results, and a conversion process well known to those skilled in the art can be used.

[0059] To further illustrate the present invention, the detection method of monomeric nitrogen, hydrogen and chlorine multidimensional stable isotopes of chloroaniline and the monitoring method of chloroaniline provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0060] In the following examples, the experimental materials and instruments are as follows:

[0061] Experimental materials: chloroaniline (o-chloroaniline, m-chloroaniline, p-chloroaniline, purity above 99.5%), carbon oxidation tube, HTC pyrolysis tube, micron-grade (250-300 μm) chromium powder, chromatographic grade dichloromethane, chromatographic grade acetone.

[0062] Instruments: gas phase-double oxidation tube-stable isotope ratio mass spectrometry (GC-CC-IRMS), gas phase-chromium packed pyrolysis tube-stable isotope ratio mass spectrometry (GC-HTC(Cr)-IRMS), gas phase-multi-collector inductively coupled plasma mass spectrometry (GC-MC-ICPMS).

[0063] In the following examples, the detection conditions are as follows:

[0064] Gas chromatography conditions: the chromatographic column is a (5%-phenyl)-methylpolysiloxane capillary column BPX-5 (size: 60m×0.25mm×0.25μm), the injection mode is the fractionation mode, the fractionation ratio is 1:5, the injection volume is 1-5μL, the injection port temperature is 260°C, the helium flow rate is 1.5mL / min, and the heating program is: the initial temperature is maintained at 60°C for 2min, the temperature is increased to 180°C at a rate of 15°C / min and maintained for 2min, and the temperature is increased to 290°C at a rate of 15°C / min and maintained for 5min.

[0065] The conditions for double oxidation tube-isotope ratio mass spectrometry detection are as follows: the combustion oxidation temperatures of the two oxidation tubes connected in series are 1000° C. (the first oxidation tube) and 600° C. (the second oxidation tube) respectively; the oxidation tube is a ceramic tube and a mixture of NiO and CuO filled in the ceramic tube, and the oxidation tube is oxidized before use to ensure that all carbon in the chloroaniline can be oxidized into carbon dioxide.

[0066] The conditions for chromium-filled pyrolysis tube-isotope ratio mass spectrometry detection are as follows: the temperature of the chromium-filled pyrolysis tube is 1200°C; the chromium-filled pyrolysis tube is a high-temperature pyrolysis tube with openings at both ends, chromium powder with a particle size of 250-300 μm is filled in the high-temperature pyrolysis tube, and the two ends of the chromium powder are sealed with quartz wool. The high-temperature pyrolysis tube was purchased from friatec Company in Germany.

[0067] The conditions for multi-collector inductively coupled plasma mass spectrometry detection preferably include: the instrument used is Neptune, operating in low resolution mode (m / Δm=400), and the gas chromatograph is connected to the multi-collector inductively coupled plasma mass spectrometer via a heated transmission line.

[0068] During the detection of the o-chloroaniline, the nitrogen isotope signal value is greater than 0.2V, the hydrogen isotope signal value is greater than 1.5V, and the chlorine isotope signal value is greater than 4V; during the detection of the m-chloroaniline, the nitrogen isotope signal value is greater than 0.1V, the hydrogen isotope signal value is greater than 0.5V, and the chlorine isotope signal value is greater than 2.5V; during the detection of the p-chloroaniline, the nitrogen isotope signal value is greater than 0.2V, the hydrogen isotope signal value is greater than 0.5V, and the chlorine isotope signal value is greater than 1V. If the signal value does not meet the above requirements, the concentration of chloroaniline is adjusted to meet the above requirements.

[0069] During the test, each sample was repeated three times to ensure the reproducibility of the test results. The standard deviations of the stable isotope ratios of nitrogen, hydrogen and chlorine met the δ 13 N: ±0.3‰, δ 2 H: ±5‰; δ 37 Cl: ±0.5‰.

[0070] An element analyzer-isotope ratio mass spectrometer (EA-IRMS) is used to test the true value of nitrogen and hydrogen in chlorobenzeneamine. The EA-IRMS consists of three parts, namely, an EA3000y element analyzer, a DeltaVAdvantage isotope ratio mass spectrometer and a Conflo IV. The test results are compared with the test results obtained by the detection method provided by the present invention to determine the accuracy of the test results.

[0071] Example 1

[0072] Detection of multidimensional stable isotopes of nitrogen, hydrogen and chlorine in o-chloroaniline.

[0073] o-chloroaniline is dissolved in acetone to obtain an o-chloroaniline mother solution with a concentration of 5000 mg / L. The chloroaniline mother solution is mixed with ultrapure water to obtain o-chloroaniline dilutions of different concentrations. Each o-chloroaniline dilution is placed in a glass reaction tube with dichloromethane, shaken on a shaking table for 4 hours at 6°C, the organic layer is an organic solution of o-chloroaniline, and the storage condition is -20°C. Among them, the concentration of the o-chloroaniline dilution is 50 mg / L, 100 mg / L or 200 mg / L when the nitrogen isotope in o-chloroaniline is detected, the concentration of the o-chloroaniline dilution is 250 mg / L, 500 mg / L and 1000 mg / L when the hydrogen isotope is detected, and the concentration of the o-chloroaniline dilution is 100 mg / L, 200 mg / L, 250 mg / L when the chlorine isotope is detected, and the concentration of the organic solution of o-chloroaniline is the same as that of the o-chloroaniline dilution.

[0074] The o-chloroaniline test solution is subjected to gas chromatography separation, and then subjected to dual oxidation tube-isotope ratio mass spectrometry detection, chromium filler pyrolysis tube-isotope ratio mass spectrometry detection and multi-collector inductively coupled plasma mass spectrometry detection, and after the determination is completed, the monomer nitrogen stable isotope ratio (δ 15 N) and hydrogen stable isotope ratio (δ 2 H), the GC-MC-ICPMS instrument output data was further corrected to obtain the chlorine stable isotope ratio of o-chloroaniline (δ 37 Cl).

[0075] Figure 3 is the nitrogen stable isotope spectrum of o-chloroaniline, Figure 4 is the hydrogen stable isotope spectrum of o-chloroaniline, Figure 5 is the chlorine stable isotope spectrum of o-chloroaniline, Figure 6 is the δ of o-chloroaniline at different signal values 15 N value (a), δ 2 H value (b), δ 37 Amplitude value diagram of Cl value (c), Figure 6 Depend on Figures 3 to 5The test data is plotted. It can be seen that when o-chloroaniline is used to determine nitrogen isotopes, the nitrogen isotope signal value is greater than 0.2V, and its nitrogen isotope ratio is not affected by concentration; when the hydrogen isotope signal value is greater than 1.5V, its isotope ratio is not affected by concentration; when the chlorine isotope signal value is greater than 4V, its isotope ratio is not affected by concentration.

[0076] Example 2

[0077] The multidimensional stable isotopes of nitrogen, hydrogen and chlorine in m-chloroaniline were detected according to the method of Example 1, the only difference from Example 1 being that o-chloroaniline was replaced by m-chloroaniline.

[0078] Figure 7 is the nitrogen stable isotope spectrum of m-chloroaniline, Figure 8 is the hydrogen stable isotope spectrum of m-chloroaniline, Fig. 9 is the chlorine stable isotope spectrum of m-chloroaniline, Fig.10 is the δ of m-chloroaniline at different signal values 15 N value (a), δ 2 H value (b), δ 37 Amplitude value diagram of Cl value (c), Fig.10 Depend on Figures 7 to 9 The test data is plotted. It can be seen that when m-chloroaniline is used to determine nitrogen isotopes, the nitrogen isotope signal value is greater than 0.1V, and its nitrogen isotope ratio is not affected by concentration; when the hydrogen isotope signal value is greater than 0.5V, its isotope ratio is not affected by concentration; when the chlorine isotope signal value is greater than 2.5V, its isotope ratio is not affected by concentration.

[0079] Example 3

[0080] The multidimensional stable isotopes of nitrogen, hydrogen and chlorine in p-chloroaniline were detected according to the method of Example 1, the only difference from Example 1 being that o-chloroaniline was replaced by p-chloroaniline.

[0081] Fig.11 is the nitrogen stable isotope spectrum of p-chloroaniline, Fig.12 is the hydrogen stable isotope spectrum of p-chloroaniline, Fig.13 is the chlorine stable isotope spectrum of p-chloroaniline, Fig.14 is the δ of p-chloroaniline at different signal values 15 N value (a), δ 2 H value (b), δ 37 Amplitude value diagram of Cl value (c), Fig.14 Depend on Figures 11 to 13 The test data is plotted. It can be seen that when determining nitrogen isotopes of p-chloroaniline, the nitrogen isotope signal value is greater than 0.2V, and its nitrogen isotope ratio is not affected by concentration; when the hydrogen isotope signal value is greater than 0.5V, its isotope ratio is not affected by concentration; when the chlorine isotope signal value is greater than 1V, its isotope ratio is not affected by concentration.

[0082] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for detecting the monomeric nitrogen, hydrogen and chlorine multidimensional stable isotopes of chloroaniline, comprising the following steps: The organic solution of chloroaniline is subjected to gas chromatography separation, and then subjected to dual oxidation tube-isotope ratio mass spectrometry detection, chromium filler pyrolysis tube-isotope ratio mass spectrometry detection and multi-collector inductively coupled plasma mass spectrometry detection, respectively, to obtain detection results of stable isotope ratios of nitrogen, hydrogen and chlorine; The chloroaniline includes o-chloroaniline, m-chloroaniline or p-chloroaniline; During the double oxidation tube-isotope ratio mass spectrometry detection process, the nitrogen isotope signal value of o-chloroaniline is greater than 0.2V, the nitrogen isotope signal value of m-chloroaniline is greater than 0.1V, and the nitrogen isotope signal value of p-chloroaniline is greater than 0.2V; During the chromium packing pyrolysis tube-isotope ratio mass spectrometry detection process, the hydrogen isotope signal value of o-chloroaniline is greater than 1.5V, the hydrogen isotope signal value of m-chloroaniline is greater than 0.5V, and the hydrogen isotope signal value of p-chloroaniline is greater than 0.5V; In the multi-collector inductively coupled plasma mass spectrometry detection process, the chlorine isotope signal value of o-chloroaniline is greater than 4V, the chlorine isotope signal value of m-chloroaniline is greater than 2.5V, and the chlorine isotope signal value of p-chloroaniline is greater than 1V.

2. The detection method according to claim 1, characterized in that: The conditions for gas chromatography separation include: a chromatographic column including a (5%-phenyl)-methylpolysiloxane capillary column, an injection mode of a fractionation mode, a fractionation ratio of 1:2-5, an injection volume of 1-5 μL, an injection port temperature of 220-260°C, a helium flow rate of 1.5 mL / min, and a heating program of maintaining an initial temperature of 60°C for 2 minutes, heating to 180°C at a rate of 15°C / min and maintaining for 2 minutes, heating to 290°C at a rate of 15°C / min and maintaining for 5 minutes.

3. The detection method according to claim 1, characterized in that: The conditions for the dual oxidation tube-isotope ratio mass spectrometry detection include: the dual oxidation tubes are two oxidation tubes connected in series, and the temperatures of the two oxidation tubes connected in series are 1000° C. and 600° C. respectively.

4. The detection method according to claim 1, characterized in that: The conditions for the chromium-filled pyrolysis tube-isotope ratio mass spectrometry detection include: the temperature of the chromium-filled pyrolysis tube is 1200°C.

5. The detection method according to claim 1, characterized in that: The conditions for the multi-collector inductively coupled plasma mass spectrometry detection include: operating in a low-resolution mode, wherein the low-resolution mode is m / Δm=400.

6. The detection method according to claim 1 or 3, characterized in that: The oxidation tube includes a ceramic tube and a mixture of NiO and CuO filled in the ceramic tube.

7. The detection method according to claim 1 or 4, characterized in that: The chromium-filled pyrolysis tube-isotope ratio mass spectrometry detection comprises a high-temperature pyrolysis tube with two ends opened and chromium powder filled in the high-temperature pyrolysis tube, and two ends of the chromium powder are blocked with quartz wool.

8. The detection method according to claim 1 or 5, characterized in that: The gas chromatograph is connected to the multi-collector inductively coupled plasma mass spectrometer via a heated transmission line, and the temperature of the heated transmission line is 250°C.

9. The detection method according to claim 1, characterized in that: The organic solvent in the organic solution of chloroaniline includes at least one of dichloromethane and n-hexane.

10. A method for monitoring chloroaniline, characterized in that: The following steps are involved: Obtaining the detection result of the stable isotope ratio of nitrogen, hydrogen and chlorine of chloroaniline according to the detection method according to any one of claims 1 to 9; The monitoring results of chloroaniline are obtained according to the detection results; the monitoring results include one or more of the following: source tracing, degradation mechanism and environmental fate.

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