Qualitative detection method and quantitative detection method for thionyl chloride in soil

Abstract

The invention discloses a qualitative detection method and a quantitative detection method for thionyl chloride in soil. The qualitative detection method comprises the following steps: extracting to-be-detected soil by adopting a derivative extraction reagent to obtain a soil extracting solution, fully mixing thionyl chloride serving as a standard substance with the derivative extraction reagent to obtain a derivative product solution, and detecting the to-be-detected soil by adopting the derivative product solution. Detecting the obtained derivative solution in a full-scanning mode by adopting a gas chromatography-mass spectrometry device so as to obtain the retention time of a derivative product, the mass-to-charge ratio of fragment ions or the abundance of the fragment ions; and detecting the soil extracting solution by adopting a gas chromatography-mass spectrometry device in a full-scanning mode, and comparing the retention time of the derivative, the mass-to-charge ratio of fragment ions or the abundance of the fragment ions, so as to realize qualitative detection of the thionyl chloride in the to-be-detected soil. The detection method provided by the invention has the advantages of good precision and accuracy, high sensitivity and strong anti-interference capability.

Description

Technical Field

[0001] The invention belongs to the technical field of thionyl chloride detection, and particularly relates to a qualitative detection method and a quantitative detection method of thionyl chloride in soil. Background Art

[0002] Sulfonyl chloride (SOCl2), also known as dichlorothionyl, is a light yellow to red fuming liquid with a density of 1.638 g / mL and a boiling point of 78.8°C. It is miscible in organic solvents such as benzene, chloroform, and carbon tetrachloride, and is hydrolyzed in water and decomposed by heating. It is a highly toxic substance and is mainly used to manufacture acyl chlorides, as well as in the production of pesticides, medicines, dyes, etc. Sulfonyl chloride has the characteristics of low boiling point, high toxicity, high corrosiveness, and water reaction. If traditional detection methods such as pressurized fluid extraction are used, it is not conducive to extraction or even impossible to extract; due to its high corrosiveness, direct sampling detection will corrode the instrument; due to its low boiling point, it will cause it to elute prematurely on the instrument or even co-elute with the solvent peak, and cannot be accurately quantified; there are currently no relevant standards and references for the detection of thionyl chloride in soil. Therefore, the development of detection methods and quality control methods for thionyl chloride in soil can better evaluate the content of thionyl chloride in soil and more comprehensively evaluate soil quality. Summary of the invention

[0003] The main purpose of the present invention is to provide a qualitative detection method and a quantitative detection method of thionyl chloride in soil to overcome the shortcomings of the prior art.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0005] The embodiment of the present invention provides a qualitative detection method of thionyl chloride in soil, which comprises:

[0006] The soil to be tested is extracted using a derivatization extraction reagent to obtain a soil extract, wherein the derivatization extraction reagent includes any one of n-propanol, isopropanol, n-butanol, isobutanol, and 2-butanol;

[0007] Using thionyl chloride as a standard substance, thionyl chloride is fully mixed with a derivatization extraction reagent to obtain a derivative product solution, and then a gas chromatography-mass spectrometry device is used to detect the obtained derivative solution in a full scan mode to obtain the retention time, fragment ion mass-to-charge ratio or fragment ion abundance of the derivative product;

[0008] Furthermore, the soil extract is detected by using a gas chromatography-mass spectrometry device in full scan mode, and the retention time, fragment ion mass-to-charge ratio or fragment ion abundance of the derivative product are compared, so as to achieve qualitative detection of thionyl chloride in the soil to be tested.

[0009] The embodiment of the present invention also provides a method for quantitatively detecting thionyl chloride in soil, which comprises:

[0010] The soil to be tested is extracted using a derivatization extraction reagent to obtain a soil extract, wherein the derivatization extraction reagent includes any one of n-propanol, isopropanol, n-butanol, isobutanol, and 2-butanol;

[0011] Using thionyl chloride as a standard substance, thionyl chloride is fully mixed with a derivatization extraction reagent to undergo a derivatization reaction to generate a stable ester compound which is used as a standard sample;

[0012] Furthermore, a gas chromatography-mass spectrometry device is used to detect and analyze the soil extract and the standard sample in an ion mode, thereby achieving quantitative detection of thionyl chloride in the soil to be tested.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a method for detecting thionyl chloride in soil, wherein 5 different derivatization extraction reagents such as n-propanol, isopropanol, n-butanol, isobutanol, and 2-butanol are added to react with thionyl chloride in soil to generate 5 different compounds such as di-n-propyl sulfite, diisopropyl sulfite, di-n-butyl sulfite, bis(1-methylpropyl) sulfite, and 2-ethylhexyl sulfite, and the content of the derivatized product is measured by gas chromatography-mass spectrometer to calculate the content of thionyl chloride; the boiling points of the 5 sulfite compounds are all greater than 100°C, and they will not co-elute with the solvent in the gas chromatography-mass spectrometer, and their relative molecular masses are all greater than 100amu, and they have abundant fragment ions in the gas chromatography-mass spectrometer, which can be better for qualitative and quantitative analysis. This method has high sensitivity and stronger anti-interference ability, and the laboratory can choose to use the extraction derivatization reagent as the detection method for thionyl chloride detection in soil according to its actual conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1a-1b is a full scan chromatogram and a full scan mass spectrum of a derivative product when the derivatization extraction reagent is n-propanol in a typical embodiment of the present invention;

[0016] Figure 2a-2b is a full scan chromatogram and a full scan mass spectrum of a derivatization product when the derivatization extraction reagent is isopropanol in a typical embodiment of the present invention;

[0017] Figure 3a-Figure 3b is a full scan chromatogram and a full scan mass spectrum of a derivative product when the derivatization extraction reagent is n-butanol in a typical embodiment of the present invention;

[0018] Figure 4a-4b is a full scan chromatogram and a full scan mass spectrum of a derivative product when the derivatization extraction reagent is 2-butanol in a typical embodiment of the present invention;

[0019] Figure 5a-Figure 5b It is a full scan chromatogram and a full scan mass spectrum of the derivative product when the derivatization extraction reagent is n-propanol in a typical embodiment of the present invention.

[0020] Figure 6a-6b It is a full scan chromatogram and a full scan mass spectrum of the soil detected in Example 1 of the present invention;

[0021] Figure 7a-Figure 7b It is a full scan chromatogram and a full scan mass spectrum of the soil detected in Example 2 of the present invention;

[0022] Figure 8a-8b It is a full scan chromatogram and a full scan mass spectrum of the soil detected in Example 3 of the present invention;

[0023] Figure 9a-9b is a full scan chromatogram and a full scan mass spectrum of the soil detected in Example 4 of the present invention;

[0024] Figure 10a-Figure 10b It is the full scan chromatogram and full scan mass spectrum of the soil detected in Example 5 of the present invention. DETAILED DESCRIPTION

[0025] In view of the defects of the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Specifically, as one aspect of the technical solution of the present invention, a qualitative detection method of thionyl chloride in soil involves:

[0027] The soil to be tested is extracted using a derivatization extraction reagent to obtain a soil extract, wherein the derivatization extraction reagent includes any one of n-propanol, isopropanol, n-butanol, isobutanol, and 2-butanol;

[0028] Using thionyl chloride as a standard substance, thionyl chloride is fully mixed with a derivatization extraction reagent to obtain a derivative product solution, and then a gas chromatography-mass spectrometry device is used to detect the obtained derivative solution in a full scan mode to obtain the retention time, fragment ion mass-to-charge ratio or fragment ion abundance of the derivative product;

[0029] Furthermore, the soil extract is detected by using a gas chromatography-mass spectrometry device in full scan mode, and the retention time, fragment ion mass-to-charge ratio or fragment ion abundance of the derivative product are compared, so as to achieve qualitative detection of thionyl chloride in the soil to be tested.

[0030] In some more specific embodiments, the qualitative detection method specifically includes: mixing the derivatization extraction reagent with the soil to be tested and extracting it by vortex oscillation, followed by centrifugation and filtration to obtain the soil extract.

[0031] Furthermore, the usage ratio of the derivatization extraction reagent to the soil to be tested is 5-10 mL: 1-2 g.

[0032] Furthermore, the extraction was performed by vortex oscillation for 2-5 min and allowed to stand for 5-10 min.

[0033] Furthermore, the centrifugal treatment adopts a centrifugal speed of 3500-6000r / min and a centrifugal time of 3-10min.

[0034] Furthermore, an organic phase filter membrane with a pore size of 0.22 μm is used for the filtration treatment.

[0035] In some more specific implementation schemes, the full scan range in the full scan mode is 35amu-200amu.

[0036] In some more specific embodiments, thionyl chloride is used as a standard substance, and the derivatization extraction reagent is n-propanol, and the derivatization product is di-n-propyl sulfite. The full scan chromatogram of the derivatization product is as follows: Figure 1a , full scan mass spectrum as Figure 1b shown.

[0037] Wherein, the reaction equation of thionyl chloride and n-propanol is shown as follows:

[0038]

[0039] In some more specific embodiments, thionyl chloride is used as the standard substance, and the derivatization extraction reagent is isopropanol, the derivatization product is diisopropyl sulfite, and the full scan chromatogram of the derivatization product is as follows: Figure 2a , full scan mass spectrum as Figure 2b shown.

[0040] Wherein, the reaction equation of thionyl chloride and isopropanol is shown as follows:

[0041]

[0042] In some more specific embodiments, thionyl chloride is used as the standard substance, and the derivatization extraction reagent is n-butanol, the derivatization product is di-n-butyl sulfite, and the full scan chromatogram of the derivatization product is as follows: Figure 3a , full scan mass spectrum as Figure 3b shown.

[0043] Among them, the reaction equation of thionyl chloride and n-butanol is shown as follows:

[0044]

[0045] In some more specific embodiments, when thionyl chloride is used as a standard substance and the derivatization extraction reagent is isobutyl alcohol, the derivatization product is bis(1-methylpropyl)sulfite, and the full scan chromatogram of the derivatization product is as follows: Figure 4a , full scan mass spectrum as Figure 4b shown.

[0046] Wherein, the reaction equation of thionyl chloride and isobutyl alcohol is shown as follows:

[0047]

[0048] In some more specific embodiments, when thionyl chloride is used as a standard substance and the derivatization extraction reagent is 2-butanol, the derivatization product is 2-ethylhexylhexyl sulfite, and the full scan chromatogram of the derivatization product is as follows: Figure 5a , full scan mass spectrum as Figure 5b shown.

[0049] Wherein, the reaction equation of thionyl chloride and 2-butanol is shown as follows:

[0050]

[0051] Another aspect of an embodiment of the present invention provides a method for quantitatively detecting thionyl chloride in soil, comprising:

[0052] The soil to be tested is extracted using a derivatization extraction reagent to obtain a soil extract, wherein the derivatization extraction reagent includes any one of n-propanol, isopropanol, n-butanol, isobutanol, and 2-butanol;

[0053] Using thionyl chloride as a standard substance, thionyl chloride is fully mixed with a derivatization extraction reagent to undergo a derivatization reaction to generate a stable ester compound which is used as a standard sample;

[0054] Furthermore, a gas chromatography-mass spectrometry device is used to detect and analyze the soil extract and the standard sample in an ion mode, thereby achieving quantitative detection of thionyl chloride in the soil to be tested.

[0055] In the present invention, any one of n-propanol, isopropanol, n-butanol, isobutanol and 2-butanol is used as a derivatization extraction reagent, thereby avoiding the defect that a low detection limit cannot be achieved by using methanol extraction. Meanwhile, when methanol is used as a derivatization extraction reagent, the product after methanol derivatization has a low boiling point and peaks very early in a gas chromatograph mass spectrometer, and is easy to co-elute with the solvent, which is not conducive to mass spectrometer detection. The relative molecular mass of the methanol derivative is less than 100 amu, which has great interference in the mass spectrometer.

[0056] In some more specific embodiments, the quantitative detection method specifically includes: mixing the derivatization extraction reagent with the soil to be tested and extracting it by vortex oscillation, and then centrifuging and filtering to obtain the soil extract.

[0057] Furthermore, the usage ratio of the derivatization extraction reagent to the soil to be tested is 5-10 mL: 1-2 g.

[0058] Furthermore, the extraction was performed by vortex oscillation for 2-5 min and allowed to stand for 5-10 min.

[0059] Furthermore, the centrifugal treatment adopts a centrifugal speed of 3500-6000r / min and a centrifugal time of 3-10min.

[0060] Furthermore, an organic phase filter membrane with a pore size of 0.22 μm is used for the filtration treatment.

[0061] In some more specific embodiments, when the derivatization extraction reagent is n-propanol, the selected ions in the ion mode are 43, 41, 125, 137, and 151.

[0062] In some more specific embodiments, when the derivatization extraction reagent is isopropanol, the selected ions in the ion mode are 43, 45, 59, and 125.

[0063] In some more specific embodiments, when the derivatization extraction reagent is n-butanol, the selected ions in the ion mode are 57, 41, 139, and 151.

[0064] In some more specific embodiments, when the derivatization extraction reagent is isobutanol, the selected ions in the ion mode are 57, 41, 87, and 139.

[0065] In some more specific embodiments, when the derivatization extraction reagent is 2-butanol, the selected ions in the ion mode are 57, 45, 101, and 139.

[0066] In some more specific embodiments, when the sampling mass is 2 g and the derivatization extraction reagent is 10 mL, the detection limit of thionyl chloride in the quantitative detection method is 0.1 mg / kg.

[0067] The invention provides a method for detecting thionyl chloride in soil. Experimental verification shows that the thionyl chloride in soil has good linearity and recovery rate, which can meet the method confirmation conditions and promote the technological progress of the detection industry.

[0068] The qualitative and quantitative detection method provided by the present invention is based on the extraction and derivatization of thionyl chloride in soil with a suitable reagent, followed by gas chromatography separation and mass spectrometry detection. The qualitative method is based on the retention time, the mass-to-charge ratio of the fragment ions and their abundance, and the quantitative method is based on the external standard method.

[0069] In some more specific embodiments, the method for detecting thionyl chloride in soil specifically comprises the following steps:

[0070] Pre-treatment method:

[0071] Weigh 1-2 g (accurate to 0.01 g) of fresh soil into a 50 mL centrifuge tube, add 5-10 mL of isopropanol solution, oscillate and extract with a high-speed oscillator for 2 min, let stand for 5 min, repeat the extraction once, place the centrifuge tube in a centrifuge, set the speed to 3500-6000 r / min, centrifuge for 3-10 min (to obtain clear supernatant), accurately aspirate 1.0 mL of the supernatant with a pipette, pass through a 0.22 μm organic phase filter membrane, and use it for gas chromatography-mass spectrometry determination.

[0072] Instrument conditions

[0073] a) Chromatographic column: HP-5 MS UI (30m×0.25mm×0.25μm) quartz capillary column

[0074] b) Column temperature program (1): 40°C for 2 min, then increase the temperature to 100°C at 15°C / min and hold for 4 min. Increase the temperature to 290°C at 10°C / min and hold for 1 min, then run at 300°C and hold for 3 min.

[0075] Or, b) Column temperature program (2) 40°C for 2 min, then increase the temperature to 300°C at 10°C / min and hold for 2 min.

[0076] c) Carrier gas: helium, purity ≥99.999%, flow rate 1.0mL / min d) Inlet temperature: 280℃

[0077] e) Injection volume: 1 μL

[0078] f) Injection mode: non-divided injection, open the diverter valve after 0.75 min, septum purge flow rate 3 mL / min

[0079] g) Electron bombardment source: 70eV

[0080] h) Ion source temperature: 230°C, quadrupole temperature: 150°C

[0081] i) GC-MS interface temperature: 280 degrees

[0082] j) Data acquisition mode: Solvent delay 5 min, qualitative analysis in full scan (SCAN) mode, quantitative analysis in ion (SIM) mode

[0083] k) Full scanning range: 35amu-200amu

[0084] (isopropanol as derivatization extraction reagent) Selected ions: 43, 45, 59, 125

[0085] (n-propanol as derivatization extraction reagent) Selected ions: 43, 41, 125, 137, 151

[0086] (n-Butanol as derivatization and extraction reagent) Selected ions: 57, 41, 139, 151

[0087] (isobutanol as derivatization extraction reagent) Selected ions: 57, 41, 87, 139

[0088] (2-Butanol as derivatization and extraction reagent) Selected ions: 57, 45, 101, 139

[0089] Calculation and discussion of results:

[0090]

[0091] Where: X——the content of thionyl chloride in the sample, unit: mg / kg

[0092] C——The concentration of the substance in the sample solution obtained from the standard working curve, in μg / mL

[0093] v——derivative extractant volume, mL

[0094] m——sample size, unit: g

[0095] f——dilution factor

[0096] The calculation result should deduct the blank value, be consistent with the detection limit, and retain no more than 3 significant digits.

[0097] After derivatization and extraction, soil samples were detected by gas chromatography-mass spectrometry, which was experimentally verified to have good precision and accuracy.

[0098] The present invention uses a derivatization method to react n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol with thionyl chloride to generate sulfite compounds, and the content of thionyl chloride is calculated by detecting the content of sulfite (the corresponding relationship is shown in Table 1 below, and the retention time in Table 1 is obtained under heating program 1).

[0099] Table 1

[0100]

[0101] Subsequent experiments proved that not every solvent could reach the lowest point of the standard curve of 20 ng / mL. Among them, n-propanol, isopropanol, n-butanol, and isobutanol could all reach this detection limit, while 2-butanol could only be used as a qualitative judgment and could not reach the lowest point of the curve.

[0102] The present invention detects the fragment ions of the reaction product sulfite under the action of the electron bombardment source of the gas chromatograph mass spectrometer, and can qualitatively characterize the product and simultaneously determine whether the product is a false positive in combination with the powerful qualitative capability of the mass spectrometer.

[0103] The invention uses n-propanol, isopropanol, n-butanol, isobutanol and 2-butanol to extract thionyl chloride in soil, and can directly allow the solvent to react with thionyl chloride to make the reaction more complete.

[0104] In terms of extraction time, the present invention uses a vortex oscillation method to extract thionyl chloride in soil at room temperature for about 10 minutes, while the traditional pressurized fluid extraction takes about 30 minutes, saving extraction time. In terms of solvent use, the use of traditional extraction methods such as pressurized fluid extractors requires the use of about 80-100 mL of solvent solution / sample, while the present invention uses about 10 mL of solvent / sample. Impact on the environment and personnel: pressurized fluid extraction will cause partial volatilization of the target compound due to heating and pressurization, entering the laboratory and causing damage to the respiratory tract of the experimenter. At the same time, the volatilization of the target compound will lead to a decrease in the recovery rate. Vortex oscillation extraction is more friendly to the environment and experimenters. In terms of extraction efficiency, vortex oscillation extraction is more efficient and has a better recovery rate than traditional pressurized fluid extraction.

[0105] The present invention does not require concentration and greatly saves pre-treatment time. The general pressurized fluid extraction pre-treatment (refer to HJ834-2017) takes 6-8 hours. The pre-treatment time of a single sample can be saved to less than 1 hour by directly passing the membrane through the machine for detection after vortex oscillation extraction, which greatly improves the detection efficiency.

[0106] The present invention can better analyze the target compound by using the optimized chromatographic conditions.

[0107] The present invention uses a full scan mode (SCAN) for qualitative analysis and a selected ion monitoring mode (SIM) for quantitative analysis, which can detect false positives and obtain extremely low detection limits and quantitative limits.

[0108] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and drawings. This embodiment is implemented on the premise of the technical solution of the invention, and a detailed implementation method and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0109] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0110] The following examples all adopt the following test conditions and calculation formulas:

[0111] Weigh 2 g of fresh soil (accurate to 0.01 g) into a 50 mL centrifuge tube, add 10 mL of derivatization extraction reagent solution, oscillate and extract with a high-speed oscillator for 2 min, let stand for 5 min, repeat the extraction once, place the centrifuge tube in a centrifuge, set the speed to 3500-6000 r / min, centrifuge for 3-10 min (to obtain clear supernatant), use a pipette to accurately aspirate 1.0 mL of the supernatant, pass through a 0.22 μm organic phase filter membrane, and use it for gas chromatography-mass spectrometry determination.

[0112] Instrument conditions:

[0113] a) Chromatographic column: HP-5 MS UI (30m×0.25mm×0.25μm) quartz capillary column

[0114] b) Column temperature program (1): 40°C for 2 min, then increase the temperature to 100°C at 15°C / min and hold for 4 min. Increase the temperature to 290°C at 10°C / min and hold for 1 min, then run at 300°C and hold for 3 min.

[0115] Or, b) Column temperature program (2) 40°C for 2 min, then increase the temperature to 300°C at 10°C / min and hold for 2 min.

[0116] c) Carrier gas: helium, purity ≥99.999%, flow rate 1.0mL / min d) Inlet temperature: 280℃

[0117] e) Injection volume: 1 μL

[0118] f) Injection mode: non-divided injection, open the diverter valve after 0.75 min, septum purge flow rate 3 mL / min

[0119] g) Electron bombardment source: 70eV

[0120] h) Ion source temperature: 230°C, quadrupole temperature: 150°C

[0121] i) GC-MS interface temperature: 280 degrees

[0122] j) Data acquisition mode: Solvent delay 5 min, qualitative analysis in full scan (SCAN) mode, quantitative analysis in ion (SIM) mode

[0123] k) Full scanning range: 35amu-200amu

[0124] Example 1

[0125] Weigh 2 g of fresh soil (accurate to 0.01 g) into a 50 mL centrifuge tube, add 10 mL of n-propanol solution, shake and extract with a high-speed oscillator for 2 min, let stand for 5 min, repeat the extraction once, put the centrifuge tube into a centrifuge, set the speed to 3500-6000 r / min and centrifuge for 3-10 min (to obtain a clear supernatant), accurately draw 1.0 mL of the supernatant with a pipette, pass it through a 0.22 μm organic phase filter membrane, and use it for gas chromatography-mass spectrometry. The selected ion (SIM) chromatogram and selected ion (SIM) mass spectrum are shown in Figure 2. Figure 6a-6b As shown, the concentration of thionyl chloride in the soil sample of the final product was 14.4604 ng / ml.

[0126] Example 2

[0127] Weigh 2 g of fresh soil (accurate to 0.01 g) into a 50 mL centrifuge tube, add 10 mL of isopropanol solution, shake and extract with a high-speed oscillator for 2 min, let stand for 5 min, repeat the extraction once, put the centrifuge tube into a centrifuge, set the speed to 3500-6000 r / min and centrifuge for 3-10 min (to obtain a clear supernatant), use a pipette to accurately draw 1.0 mL of the supernatant, pass it through a 0.22 μm organic phase filter membrane, and use it for gas chromatography-mass spectrometry. The selected ion (SIM) chromatogram and selected ion (SIM) mass spectrum are shown in Figure 2. Figure 7a-Figure 7b As shown, the concentration of thionyl chloride in the soil sample of the final product was 21.2989 ng / ml.

[0128] Example 3

[0129] Weigh 2 g of fresh soil (accurate to 0.01 g) into a 50 mL centrifuge tube, add 10 mL of n-butanol solution, shake and extract with a high-speed oscillator for 2 min, let stand for 5 min, repeat the extraction once, put the centrifuge tube into a centrifuge, set the speed to 3500-6000 r / min and centrifuge for 3-10 min (to obtain a clear supernatant), accurately draw 1.0 mL of the supernatant with a pipette, pass through a 0.22 μm organic phase filter membrane, and use it for gas chromatography-mass spectrometry. The selected ion (SIM) chromatogram and selected ion (SIM) mass spectrum are shown in Figure 2. Figure 8a-8b As shown, the concentration of thionyl chloride in the soil sample of the final product was 52.69259.

[0130] Example 4

[0131] Weigh 2 g of fresh soil (accurate to 0.01 g) into a 50 mL centrifuge tube, add 10 mL of isobutanol solution, shake and extract with a high-speed oscillator for 2 min, let stand for 5 min, repeat the extraction once, put the centrifuge tube into a centrifuge, set the speed to 3500-6000 r / min and centrifuge for 3-10 min (to obtain a clear supernatant), use a pipette to accurately draw 1.0 mL of the supernatant, pass it through a 0.22 μm organic phase filter membrane, and use it for gas chromatography-mass spectrometry. The selected ion (SIM) chromatogram and selected ion (SIM) mass spectrum are shown in Figure 2. Figure 9a-9b As shown, the concentration of thionyl chloride in the soil sample of the final product was 77.8109 ng / ml.

[0132] The sample spike test in Examples 1-4 is shown in Table 2:

[0133]

[0134] Example 5

[0135] The method is the same as in Example 1, except that a 100 μg / mL benzo(a)pyrene standard substance is added to the soil. The selected ion chromatogram and selected ion mass spectrum are shown in FIG. Figure 10a-Figure 10b As shown, the concentration of thionyl chloride in the soil sample of the final product is 480.7703 ng / ml.

[0136] The spiked test is shown in Table 3:

[0137] Table 3

[0138]

[0139] Example 6

[0140] The detection limit and minimum detection limit of the method in the present invention are as follows:

[0141] Take 7 portions of quartz sand to replace the test sample and prepare parallel samples with a spiked amount of 0.1 mg / kg. According to all the steps of sample analysis, calculate the standard deviation of 7 parallel determinations and then calculate the method detection limit according to formula (2). Take 1 to 5 times the method detection limit as the laboratory report limit.

[0142] The determination result is converted into sample content according to formula (1):

[0143]

[0144] Where:

[0145] Where: X——the content of thionyl chloride in the sample, unit: mg / kg

[0146] C——The concentration of the substance in the sample solution obtained from the standard working curve, in μg / mL

[0147] v——derivative extractant volume, mL

[0148] m——sample size, unit: g

[0149] f——dilution factor

[0150] The detection limit of the method is calculated according to formula (2):

[0151] MDL= t(n-1，09) ×S (2)

[0152] Where: MDL – method detection limit;

[0153] n——number of parallel determinations of samples;

[0154] t——t distribution (one-sided) when the degrees of freedom are n-1 and the confidence level is 99%. When n=7, t (n-1，09) =3.143;

[0155] S is the standard deviation of n parallel measurements.

[0156] The results of the method detection limit test are as follows:

[0157] Table 4 Method detection limit, determination lower limit test results

[0158]

[0159] Table 5 Method detection limit, determination lower limit test results

[0160]

[0161] Table 6 Method detection limit and determination lower limit test results

[0162]

[0163] Table 7 Method detection limit, determination lower limit test results

[0164]

[0165] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0166] It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific implementation cases. Any technical deformation made according to the technical solution of the present invention without departing from the scope of protection of the purpose of the present invention and the claims shall fall within the protection scope of the present invention.

Claims

1. A qualitative detection method for thionyl chloride in soil, characterized in that, include: The soil to be tested is extracted using a derivatization extraction reagent to obtain a soil extract, wherein the derivatization extraction reagent includes any one of n-propanol, isopropanol, n-butanol, isobutanol, and 2-butanol; Using thionyl chloride as a standard substance, thionyl chloride is fully mixed with a derivatization extraction reagent to obtain a derivative product solution, and then a gas chromatography-mass spectrometry device is used to detect the obtained derivative solution in a full scan mode to obtain the retention time, fragment ion mass-to-charge ratio or fragment ion abundance of the derivative product; Furthermore, the soil extract is detected by using a gas chromatography-mass spectrometry device in full scan mode, and the retention time, fragment ion mass-to-charge ratio or fragment ion abundance of the derivative product are compared, so as to achieve qualitative detection of thionyl chloride in the soil to be tested.

2. The qualitative detection method according to claim 1, characterized in that: Specifically include: The derivatization extraction reagent is mixed with the soil to be tested and extracted by vortex oscillation, and then centrifuged and filtered to obtain the soil extract.

3. The qualitative detection method according to claim 2, characterized in that: The usage ratio of the derivatization extraction reagent to the soil to be tested is 5-10 mL: 1-2 g.

4. The qualitative detection method according to claim 2, characterized in that: Extract by vortexing for 2-5 minutes and let stand for 5-10 minutes; And / or, the centrifugal speed used in the centrifugal treatment is 3500-6000r / min, and the centrifugal time is 3-10min And / or, an organic phase filter membrane with a pore size of 0.22 μm is used for the filtration treatment.

5. The qualitative detection method according to claim 1, characterized in that: The full scan range in the full scan mode is 35amu-200amu.

6. A quantitative detection method for thionyl chloride in soil, characterized in that: include: The soil to be tested is extracted using a derivatization extraction reagent to obtain a soil extract, wherein the derivatization extraction reagent includes any one of n-propanol, isopropanol, n-butanol, isobutanol, and 2-butanol; Using thionyl chloride as a standard substance, thionyl chloride is fully mixed with a derivatization extraction reagent to undergo a derivatization reaction to generate a stable ester compound which is used as a standard sample; Furthermore, a gas chromatography-mass spectrometry device is used to detect and analyze the soil extract and the standard sample in an ion mode, thereby realizing the quantitative detection of thionyl chloride in the soil to be tested.

7. The quantitative detection method according to claim 6, characterized in that: Specifically include: The derivatization extraction reagent is mixed with the soil to be tested and extracted by vortex oscillation, and then centrifuged and filtered to obtain the soil extract.

8. The quantitative detection method according to claim 7, characterized in that: The usage ratio of the derivatization extraction reagent to the soil to be tested is 5-10 mL: 1-2 g; and / or, extracting by vortexing for 2-5 min and letting stand for 5-10 min; And / or, the centrifugal treatment adopts a centrifugal speed of 3500-6000 r / min and a centrifugal time of 3-10 min; And / or, an organic phase filter membrane with a pore size of 0.22 μm is used for the filtration treatment.

9. The quantitative detection method according to claim 6, characterized in that: When the derivatization extraction reagent is n-propanol, the selected ions in the ion mode are 43, 41, 125, 137, and 151; And / or, when the derivatization extraction reagent is isopropanol, the selected ions in the ion mode are 43, 45, 59, 125; And / or, when the derivatization extraction reagent is n-butanol, the selected ions in the ion mode are 57, 41, 139, 151; and / or, when the derivatization extraction reagent is isobutanol, the selected ions in the ion mode are 57, 41, 87, 139; And / or, when the derivatization extraction reagent is 2-butanol, the selected ions in the ion mode are 57, 45, 101, and 139.

10. The quantitative detection method according to claim 6, characterized in that: When the sampling mass is 2 g and the derivatization extraction reagent is 10 mL, the detection limit of thionyl chloride in the quantitative detection method is 0.1 mg / kg.

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