Method for detecting concentration of chlorantraniliprole and flubendiamide in sediment

Abstract

The invention provides a method for detecting the concentration of chlorantraniliprole and flubendiamide in sediment, and relates to the technical field of ecological toxicology. The specific testing method comprises the following steps: mixing a to-be-tested substance solution with artificial sediments to prepare labeled sediments with different to-be-tested substance concentrations, wherein the concentration unit is mg / kg; treating the labeled sediments with different to-be-detected substance concentrations to obtain standard detection solutions with different to-be-detected substance concentrations; detecting the standard detection solutions with different concentrations of the substances to be detected by adopting a high performance liquid chromatography-mass spectrometer to obtain a concentration-peak area standard curve; sequentially carrying out sampling, freeze-drying, crushing, extraction, adsorption purification, centrifugation, nitrogen blowing and constant volume on a sediment to be detected to obtain a liquid to be detected; the high performance liquid chromatography-mass spectrometer is adopted to detect the to-be-detected liquid, the concentration of the to-be-detected substance in the to-be-detected sediment is obtained according to a standard curve method, and the blank of qualitative and quantitative detection of bisamide pesticides in the sediment at present is filled.

Description

Technical Field

[0001] The present invention relates to the technical field of ecotoxicology, and particularly relates to a method for detecting the concentrations of chlorantraniliprole and broflanilide in sediments. Background Art

[0002] Diamide insecticides have been a hot topic in the field of pesticide research in recent years. They act on the ryanodine receptor of insects and have the advantages of novel action mechanism, high efficiency, and no cross-resistance with traditional pesticides. Due to their characteristics of easy adsorption and difficult degradation in the environment, they can migrate to sediments after entering natural water bodies and may pose a threat to benthic organisms. The impact of diamide insecticides on benthic organisms has increasingly become a hot topic in current research. The sediment spiking method is the main method for studying the chronic toxicity of pesticides to benthic organisms, which is characterized by high sensitivity, strong repeatability, relatively simple operation, and being relatively similar to natural conditions. However, due to the usually low concentration of the test drugs and the high content of organic matter in sediments, the pesticide adsorption effect is enhanced, and it is difficult to accurately, quickly, and conveniently detect the concentration of the test drugs in the samples.

[0003] Currently, there is no detection method for chlorantraniliprole and broflanilide in sediments. The published detection methods for soil and plants are not applicable to the detection of chlorantraniliprole and broflanilide in sediments. Therefore, it is imperative to invent a rapid and efficient detection method for chlorantraniliprole and broflanilide in sediments that meets the test requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for detecting the concentrations of chlorantraniliprole and broflanilide in sediments to fill the blank of qualitative and quantitative detection of chlorantraniliprole and broflanilide in sediments at present.

[0005] In order to achieve the above invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a method for detecting the concentrations of chlorantraniliprole and broflanilide in sediments, comprising the following steps:

[0007] 1) Prepare a standard solution with gradient concentrations of the standard substance of the analyte using acetonitrile, and mix the standard solution with gradient concentrations with artificial sediment to obtain spiked sediments with different analyte concentrations, and the concentration unit is mg / kg;

[0008] 2) Sequentially sample, freeze-dry, crush, extract, adsorb and purify, centrifuge, nitrogen blow, and make up the volume of the spiked sediments with different analyte concentrations to obtain standard detection solutions with different analyte concentrations;

[0009] 3) Use a high performance liquid chromatography-mass spectrometry (HPLC-MS) instrument to detect standard test solutions with different concentrations of analytes, and obtain a concentration-peak area standard curve;

[0010] 4) Sequentially sample, freeze-dry, pulverize, extract, adsorb and purify, centrifuge, nitrogen blow, and make up the volume of the sediment to be tested to obtain a test solution;

[0011] Use a high performance liquid chromatography-mass spectrometry (HPLC-MS) instrument to detect the test solution, and obtain the concentration of the analyte in the sediment to be tested according to the standard curve method;

[0012] The analyte is chlorantraniliprole or broflanilide;

[0013] Among them, when the analyte is chlorantraniliprole, the extraction in steps 2) and 4) independently uses ethyl acetate as the extractant;

[0014] When the analyte is broflanilide, the extraction in steps 2) and 4) independently uses an acetonitrile solution of formic acid as the extractant, and the volume concentration of formic acid is 0.1%.

[0015] Preferably, the preparation method of the artificial sediment in step 1) is: air-dry and pulverize sphagnum moss, mix it with water to form a suspension, domesticate the suspension for 2 days, and then mix it with quartz sand, kaolin and deionized water to obtain artificial sediment;

[0016] The pH value of the artificial sediment is 6.5-7.5, and the water content is 38-42% of the dry weight of the sediment.

[0017] Preferably, when the analyte is chlorantraniliprole, the content range of the analyte in the spiked sediment in step 1) is 0.01-1.0 mg / kg;

[0018] When the analyte is broflanilide, the content range of the analyte in the spiked sediment in step 1) is 0.01-1.0 mg / kg.

[0019] Preferably, when the analyte is chlorantraniliprole, the mobile phase of the high performance liquid chromatography in the high performance liquid chromatography-mass spectrometry instrument in step 3) is an acetonitrile-formic acid aqueous solution with a volume ratio of 10-90:85-15, where the volume concentration of the formic acid aqueous solution is 0.1%, the flow rate of the eluent is 0.5 mL / min, and the injection volume is 15-20 μL.

[0020] Preferably, when the analyte is chlorantraniliprole, the ion source of the mass spectrometer in the high performance liquid chromatography-mass spectrometry instrument in step 3) is an electrospray ion source, the voltage of the ion source is 4200-5500 V, and the temperature of the ion source is 500-650 °C.

[0021] Preferably, when the analyte is broflanilide, in the high performance liquid chromatography-mass spectrometry instrument described in step 3), the mobile phase of the high performance liquid chromatography has a volume ratio of acetonitrile-formic acid aqueous solution of 20-80:80-20, where the volume concentration of the formic acid aqueous solution is 0.1%, the flow rate of the eluent is 0.4 mL / min, and the injection volume is 5-20 μL.

[0022] Preferably, when the analyte is broflanilide, the ion source of the mass spectrometer in the high performance liquid chromatography-mass spectrometry instrument described in step 3) is an electrospray ionization source, the voltage of the ion source is 4200-5500 V, and the temperature of the ion source is 500-650 °C.

[0023] Preferably, when the analyte is chlorantraniliprole, the retention time is 1.4 min, and when the analyte is broflanilide, the retention time is 2.46 min.

[0024] The present invention has at least the following beneficial effects:

[0025] The present invention has developed for the first time a detection method for chlorantraniliprole and broflanilide in sediment, filling the relevant gaps in the industry and laying a foundation for comprehensively evaluating the toxicity effects of pesticides on benthic organisms. This method has simple pretreatment, high sensitivity, good selectivity, short analysis time, and strong reproducibility. Description of the Drawings

[0026] Figure 1 It is the chromatogram when the content of chlorantraniliprole added to the sediment is 0.01 mg / kg;

[0027] Figure 2 It is the chromatogram when the content of chlorantraniliprole added to the sediment is 0.1 mg / kg;

[0028] Figure 3 It is the chromatogram when the content of chlorantraniliprole added to the sediment is 1 mg / kg;

[0029] Figure 4 It is the chromatogram when the content of broflanilide added to the sediment is 0.01 mg / kg;

[0030] Figure 5 It is the chromatogram when the content of broflanilide added to the sediment is 0.1 mg / kg;

[0031] Figure 6 It is the chromatogram when the content of broflanilide added to the sediment is 1 mg / kg;

[0032] Figure 7 It is the standard curve of chlorantraniliprole provided in Example 1 of the present invention;

[0033] Figure 8 This is the standard curve graph of broflanilide provided in Embodiment 2 of the present invention. Specific embodiments

[0034] The present invention provides a method for detecting the concentrations of chlorantraniliprole and broflanilide in sediments, comprising the following steps:

[0035] 1) Prepare standard solutions with gradient concentrations of the standard substances of the analytes using acetonitrile, and mix the standard solutions with gradient concentrations with artificial sediments to obtain spiked sediments with different analyte concentrations, and the concentration unit is mg / kg;

[0036] 2) Sequentially sample, freeze-dry, pulverize, extract, adsorb and purify, centrifuge, nitrogen blow, and make up the volume of the spiked sediments with different analyte concentrations to obtain standard test solutions with different analyte concentrations;

[0037] 3) Use a high performance liquid chromatography-mass spectrometry (HPLC-MS) instrument to detect the standard test solutions with different analyte concentrations to obtain a concentration-peak area standard curve;

[0038] 4) Sequentially sample, freeze-dry, pulverize, extract, adsorb and purify, centrifuge, nitrogen blow, and make up the volume of the sediment to be tested to obtain a test solution;

[0039] Use a high performance liquid chromatography-mass spectrometry (HPLC-MS) instrument to detect the test solution, and obtain the concentration of the analyte in the sediment to be tested according to the standard curve method;

[0040] The analyte is chlorantraniliprole or broflanilide;

[0041] Among them, when the analyte is chlorantraniliprole, ethyl acetate is independently used as the extraction agent in steps 2) and 4);

[0042] When the analyte is broflanilide, an acetonitrile solution of formic acid with a volume concentration of 0.1% is independently used as the extraction agent in steps 2) and 4).

[0043] In the present invention, the preparation method of the artificial sediment in step 1) is: air-dry and pulverize sphagnum moss, mix it with water to form a suspension, domesticate the suspension for 2 days, and then mix it with quartz sand, kaolin and deionized water to obtain artificial sediment;

[0044] The pH value of the artificial sediment is 6.5 - 7.5, preferably 6.8 - 7.3, and more preferably 7; the water content is 38 - 42% of the dry weight of the sediment, preferably 39 - 41%, and more preferably 40%.

[0045] In the present invention, when the analyte is chlorantraniliprole, the content range of the analyte in the spiked sediment in step 1) is 0.01 - 1.0 mg / kg, and it can be 0.01 mg / kg, 0.05 mg / kg, 0.1 mg / kg, 0.2 mg / kg, 0.3 mg / kg, 0.4 mg / kg, 0.5 mg / kg, 0.6 mg / kg, 0.7 mg / kg, 0.8 mg / kg, 0.9 mg / kg, 1.0 mg / kg.

[0046] In the present invention, when the analyte is broflanilide, the content range of the analyte in the spiked sediment in step 1) is 0.01 - 1.0 mg / kg, and it can be 0.01 mg / kg, 0.05 mg / kg, 0.1 mg / kg, 0.2 mg / kg, 0.3 mg / kg, 0.4 mg / kg, 0.5 mg / kg, 0.6 mg / kg, 0.7 mg / kg, 0.8 mg / kg, 0.9 mg / kg, 1.0 mg / kg.

[0047] In the present invention, when the analyte is chlorantraniliprole, the mobile phase of the high performance liquid chromatography in the high performance liquid chromatography - mass spectrometry in step 3) is an acetonitrile - formic acid aqueous solution with a volume ratio of 10 - 90:85 - 15, wherein the volume concentration of the formic acid aqueous solution is 0.1%, the flow rate of the eluent is 0.5 mL / min, and the injection volume is 15 - 20 μL.

[0048] In the present invention, when the analyte is chlorantraniliprole, the ion source of the mass spectrometer in the high performance liquid chromatography - mass spectrometry in step 3) is an electrospray ion source, the voltage of the ion source is 4200 - 5500 V, preferably 4300 - 5300 V, further preferably 4500 - 5000 V, and more preferably 4800 - 5500 V; the temperature of the ion source is 500 - 650 °C, preferably 530 - 630 °C, further preferably 550 - 600 °C, and more preferably 580 °C.

[0049] In the present invention, when the analyte is broflanilide, the mobile phase of the high performance liquid chromatography in the high performance liquid chromatography - mass spectrometry in step 3) has a volume ratio of 20 - 80:80 - 20 of acetonitrile - formic acid aqueous solution, wherein the volume concentration of the formic acid aqueous solution is 0.1%, the flow rate of the eluent is 0.4 mL / min, and the injection volume is 5 - 20 μL.

[0050] In the present invention, when the analyte is broflanilide, the ion source of the mass spectrometer in the high performance liquid chromatography-mass spectrometry (HPLC-MS) in step 3) is an electrospray ionization source, the voltage of the ion source is 4200 - 5500 V, preferably 4300 - 5300 V, further preferably 4500 - 5000 V, and more preferably 4800 - 5500 V; the temperature of the ion source is 500 - 650 °C, preferably 530 - 630 °C, further preferably 550 - 600 °C, and more preferably 580 °C.

[0051] In the present invention, when the analyte is chlorantraniliprole, the retention time is 1.4 min.

[0052] In the present invention, when the analyte is broflanilide, the retention time is 2.46 min.

[0053] The technical solutions provided by the present invention will be described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0054] Example 1

[0055] (1) 10 mg of chlorantraniliprole standard substance (purity 98.2%, National Pesticide Quality Inspection Center (Shenyang)) was dissolved in 100 mL of acetonitrile (chromatographic grade, Sigma - Aldrich, Co.) to prepare a chlorantraniliprole stock solution with a concentration of 100 mg / L, and then diluted with acetonitrile to prepare chlorantraniliprole standard solutions with concentration gradients of 0.5 μg / L, 1.0 μg / L, 5 μg / L, 10 μg / L, 50 μg / L, and 100 μg / L.

[0056] (2) Artificial sediment was prepared according to the OECD guideline "OECD 218 Sediment Spiking - Aquatic Chironomid Toxicity Test". Quartz sand, kaolin, and sphagnum moss were weighed according to the mass ratio of quartz sand:kaolin:sphagnum moss = 75:20:5. First, the sphagnum moss was air - dried and ground into powder, and deionized water was added to make a sphagnum suspension. The pH value of the sphagnum suspension was adjusted to 5.5 with calcium carbonate, and the suspension was acclimated at 20 ± 2 °C for 2 days to stabilize the pH and establish a stable microbial composition. After acclimation, the pH value of the system was 6.5. Then, the sphagnum suspension was mixed with the weighed quartz sand, kaolin, and deionized water to obtain an artificial sediment with a water content of 40% of the dry weight of the sediment, and the pH value of the system was adjusted to 7.0 with calcium carbonate.

[0057] (3) Mix the chlorantraniliprole standard solution with artificial sediment to obtain spiked sediments with chlorantraniliprole contents of 0.01 mg / kg, 0.1 mg / kg, and 1.0 mg / kg respectively. After mixing and allowing the sediment to stand and layer, pour out the overlying water. Insert a PVC haff pipe vertically into the sediment from top to bottom for sampling. Dry the extracted columnar sediment in a freeze dryer under a temperature setting program from room temperature to -50°C to 20°C for 19 h. Then, crush the freeze-dried sample. Take 5 g of the sample powder and add 10 mL of ethyl acetate for extraction. Use an IKAMS 3 vortex mixer to vortex the mixed system for 2 min, then ultrasonically oscillate for 15 min. Add 2 g of C18 for adsorption and purification. Centrifuge the mixed system at 5000 r / min for 10 min. Take 5 mL of the supernatant and dry it with a nitrogen blower, then add acetonitrile to make up the volume to 50 mL to obtain the standard test solution. Take 2 mL of the above solution and filter it through a 0.22 μm organic filter membrane for on-machine detection.

[0058] Repeat the above operations to obtain standard test solutions with different analyte contents.

[0059] (4) Use a triple quadrupole liquid chromatography-mass spectrometry instrument (Shimadzu 20AD-AB Sciex TRIPLE QUAD 4000) to detect the standard test solutions with different analyte concentrations.

[0060] High-performance liquid chromatography conditions: The chromatographic column is Agilent ZORBAX Extend C18 (2.1×50 mm, 3.5 μm), the column temperature is 40°C, the injection volume is 20 μL, and the gradient elution conditions are shown in Table 1.

[0061] Table 1 Gradient elution conditions for detecting chlorantraniliprole

[0062]

[0063] Mass spectrometry conditions: Electrospray ionization source ESI; Scanning mode: positive ion; Ion source voltage: 4200 V.

[0064] Ion source temperature: 500°C; Curtain Gas: 25 psi; GS1, GS2: 50 psi; EP voltage: 10 V; CXP voltage: 10 V; DP voltage: 50 V; The mass spectrometry conditions are shown in Table 2.

[0065] Table 2 Mass spectrometry conditions for detecting chlorantraniliprole

[0066]

[0067] The concentration and peak area data of chlorantraniliprole are shown in Table 3. Using the solution concentration as the abscissa and the peak area as the ordinate, we get as Figure 7The standard curve shown: y1 = 4140x + 451 (correlation coefficient is 0.9966, limit of quantification LOQ is 0.01 mg / kg).

[0068] Table 3 Standard solutions of chlorantraniliprole at different concentrations and their peak areas

[0069]

[0070] Recovery experiment:

[0071] Different concentrations of chlorantraniliprole were added to the artificial sediment, and the addition levels were 0.01 mg / kg, 0.1 mg / kg, and 1 mg / kg respectively. The concentration of chlorantraniliprole in the artificial sediment was tested according to the sampling and testing methods described in steps (3) and (4) of this example, and a spike recovery test was carried out. Five replicates were set for each level. The detection spectra of the artificial sediment with chlorantraniliprole addition levels of 0.01 mg / kg, 0.1 mg / kg, and 1 mg / kg are as Figures 1 to 3 shown, and the specific test results and recoveries are shown in Table 4:

[0072] Table 4 Results of the spike recovery test of chlorantraniliprole

[0073]

[0074] The results show that the average recovery rate of chlorantraniliprole in the sediment is 91.2% - 104.3%, and the relative standard deviation (RSD) is 4.1% - 4.5%; the accuracy and precision of the method meet the requirements of pesticide residue analysis and can be used for the analysis of actual residue samples.

[0075] Detection of actual samples:

[0076] (1) During the chironomid test, 100 g of spiked sediment was taken at 1 h, 9 d, and 18 d respectively. The addition concentrations of chlorantraniliprole in the sediment were 0.01 mg / kg, 0.04 mg / kg, and 0.16 mg / kg respectively. After mixing 100 g of sediment evenly and allowing it to stand and layer, the overlying water was poured out. A PVC Hav pipe was inserted into the sediment from top to bottom for sampling. The taken columnar sediment was dried in a freeze dryer under the temperature setting program from room temperature to -50°C to 20°C for 19 h. Then the freeze-dried sample was crushed. 5 g of the sample powder was added with 10 mL of ethyl acetate for extraction. The mixed system was vortexed for 2 min using an IKAMS 3 vortex mixer, and then ultrasonically oscillated for 15 min. 2 g of C18 was added for adsorption and purification. The mixed system was centrifuged at 5000 r / min for 10 min. 5 mL of the supernatant was taken and dried with a nitrogen blower, and then fixed volume to 50 mL with acetonitrile to obtain the test solution. 2 mL of the above solution was passed through a 0.22 μm organic filter membrane and waited for on-machine detection.

[0077] (2) A triple quadrupole liquid chromatography-mass spectrometry (Shimadzu 20AD-AB Sciex TRIPLE QUAD 4000) was used to detect the standard test solutions with different analyte concentrations.

[0078] High performance liquid chromatography conditions: The chromatographic column was Agilent ZORBAX Extend C18 (2.1×50 mm, 3.5 μm), the column temperature was 40°C, the injection volume was 20 μL, and the gradient elution conditions were as shown in Table 1.

[0079] Mass spectrometry conditions: Electrospray ionization source ESI; Scanning mode: Positive ion; Ion source voltage: 4200 V.

[0080] Ion source temperature: 500°C; Curtain Gas: 25 psi; GS1, GS2: 50 psi; EP voltage: 10 V; CXP voltage: 10 V; DP voltage: 50 V; The mass spectrometry conditions were as shown in Table 2.

[0081] The results showed that: When this method was used for qualitative and quantitative detection of chlorantraniliprole in sediment samples during the actual chironomid test, the pretreatment was simple, the sensitivity was high, the selectivity was good, the analysis time was short, and the method had strong reproducibility. The specific test results and recovery rates were as shown in Table 5:

[0082] Table 5 Determination results of chlorantraniliprole in sediment during the chironomid test

[0083]

[0084]

[0085] Example 2

[0086] (1) Weigh 10 mg of the reference substance of broflanilide (purity > 98%, Shanghai Macklin Biochemical Co., Ltd.) and dissolve it in 100 mL of acetonitrile (chromatographically pure, Sigma - Aldrich, Co.) to prepare a broflanilide stock solution with a concentration of 100 mg / L. Then dilute it with acetonitrile to prepare broflanilide standard solutions with concentration gradients of 0.5 μg / L, 1.0 μg / L, 5 μg / L, 10 μg / L, 20 μg / L, 50 μg / L, 100 μg / L, and 200 μg / L.

[0087] (2) Prepare artificial sediment according to the OECD guideline "OECD 218 Sediment Spiking - Aquatic Chironomid Toxicity Test". Weigh quartz sand, kaolin, and sphagnum moss according to the mass ratio of quartz sand:kaolin:sphagnum moss = 75:20:5. First, air - dry the sphagnum moss and then grind it into powder. Add deionized water to make a sphagnum suspension, and adjust the pH value of the sphagnum suspension to 5.5 with calcium carbonate. Acclimatize the suspension at 20 ± 2 °C for 2 days to stabilize the pH and establish a stable microbial composition. After acclimatization, the pH value of the system is 6.5. Then mix the sphagnum suspension with the weighed quartz sand, kaolin, and deionized water to obtain artificial sediment with a water content of 40% of the dry weight of the sediment, and adjust the pH value of the system to 7.0 with calcium carbonate.

[0088] (3) Mix the broflanilide standard solutions with the artificial sediment to obtain spiked sediments with broflanilide contents of 0.01 mg / kg, 0.1 mg / kg, and 1.0 mg / kg respectively. After mixing and allowing the sediment to stand and layer, pour out the overlying water. Insert a PVC haff - pipe vertically into the sediment from top to bottom for sampling. Dry the taken columnar sediment in a freeze - dryer according to the temperature - setting program from room temperature to - 50 °C and then to 20 °C for 19 h. Then crush the freeze - dried sample. Take 5 g of the sample powder and add it to 10 mL of acetonitrile solution containing 0.1% formic acid by volume for extraction. Use an IKAMS 3 vortex mixer to vortex the mixed system for 2 min, then ultrasonically oscillate for 15 min. Add 2 g of C18 for adsorption and purification. Centrifuge the mixed system at 5000 r / min for 10 min. Take 5 mL of the supernatant and dry it with a nitrogen blower, then add acetonitrile to make the volume up to 50 mL to obtain the standard test solution. Take 2 mL of the above solution and filter it through a 0.22 - μm organic filter membrane for on - machine detection.

[0089] Repeat the above operations to obtain standard test solutions with different analyte concentrations.

[0090] (4) Use a triple - quadrupole liquid chromatography - mass spectrometry (Shimadzu 20AD - AB Sciex TRIPLE QUAD 4000) to detect the standard test solutions with different analyte concentrations.

[0091] High performance liquid chromatography conditions: The chromatographic column is Agilent ZORBAX Extend C18 (2.1×50 mm, 3.5 μm), the column temperature is 30 °C, the injection volume is 10 μL, and the gradient elution conditions are shown in Table 6.

[0092] Table 6 Gradient elution conditions for detecting broflanilide

[0093]

[0094] Mass spectrometry conditions: Electrospray ionization source ESI; Scanning mode: positive ion; Ion source voltage: 4200 V. Ion source temperature: 450 °C; Curtain Gas: 35 psi; GS1, GS2: 35 psi, 35 psi;

[0095] EP voltage: 10 V; CXP voltage: 10 V; The mass spectrometry conditions are shown in Table 7.

[0096] Table 7 Mass spectrometry conditions for detecting broflanilide

[0097]

[0098] The concentration and peak area data of broflanilide are shown in Table 8. With the solution concentration as the abscissa and the peak area as the ordinate, the standard curve obtained is as Figure 8 shown: y2 = 8420x + 10800 (correlation coefficient is 0.9972, limit of quantification LOQ is 0.01 mg / kg).

[0099] Table 8 Standard solutions of broflanilide at different concentrations and their peak areas

[0100]

[0101] Recovery experiment:

[0102] Different concentrations of broflanilide were added to the artificial sediment, and the addition levels were 0.01 mg / kg, 0.1 mg / kg, and 1 mg / kg respectively. According to the sampling and testing methods described in steps (3) and (4) of this example, the concentration of broflanilide in the artificial sediment was tested, and a spike recovery test was carried out. Five replicates were set for each level. The detection spectra of the artificial sediment with broflanilide addition levels of 0.01 mg / kg, 0.1 mg / kg, and 1 mg / kg are as Figures 4 to 6 shown, and the specific test results and recoveries are shown in Table 9:

[0103] Table 9 Results of the spike recovery test of broflanilide

[0104]

[0105]

[0106] The results showed that the average recovery rate of broflanilide in sediments was 81.6% - 94.2%, and the relative standard deviation (RSD) was 4.3% - 6.2%. The accuracy and precision of the method met the requirements of pesticide residue analysis and could be used for the analysis of actual residue samples.

[0107] Detection of actual samples:

[0108] (1) During the chironomid test, 100 g of spiked sediments were taken at 1 h, 9 d, and 18 d respectively, and the added concentrations of broflanilide in the sediments were 0.01 mg / kg, 0.16 mg / kg, and 0.32 mg / kg respectively. After mixing 100 g of sediments evenly and allowing them to stand and layer, the overlying water was poured out. A PVC Hav pipe was inserted into the sediments from top to bottom for sampling. The taken columnar sediments were dried in a freeze dryer for 19 h according to the temperature setting program from room temperature to -50 °C to 20 °C. Then the freeze-dried samples were crushed, and 5 g of sample powder was added to 10 mL of acetonitrile solution containing 0.1% formic acid by volume for extraction. The mixed system was vortexed for 2 min using an IKA MS 3 vortex mixer, then ultrasonically oscillated for 15 min, 2 g of C18 was added for adsorption and purification, the mixed system was centrifuged at 5000 r / min for 10 min, 5 mL of the supernatant was taken and dried with a nitrogen blower, and then acetonitrile was added to make up the volume to 50 mL to obtain the test solution. 2 mL of the above solution was taken and passed through a 0.22 μm organic filter membrane for on-machine detection.

[0109] (2) A triple quadrupole liquid chromatography - mass spectrometry (Shimadzu 20AD - AB Sciex TRIPLE QUAD 4000) was used to detect the standard test solutions with different analyte concentrations.

[0110] High - performance liquid chromatography conditions: The chromatographic column was Agilent ZORBAX Extend C18 (2.1×50 mm, 3.5 μm), the column temperature was 30 °C, the injection volume was 10 μL, and the gradient elution conditions were as shown in Table 6.

[0111] Mass spectrometry conditions: Electrospray ionization source ESI; Scanning mode: positive ion; Ion source voltage: 4200 V.

[0112] Ion source temperature: 450 °C; Curtain Gas: 35 psi; GS1, GS2: 35 psi, 35 psi;

[0113] EP voltage: 10 V; CXP voltage: 10 V; The mass spectrometry conditions were as shown in Table 7.

[0114] The results show that: when this method is used for the qualitative and quantitative detection of broflanilide in actual chironomid tests and sediment samples, the pretreatment is simple, the sensitivity is high, the selectivity is good, the analysis time is short, and the method has strong reproducibility. The specific test results and recovery rates are shown in Table 10:

[0115] Table 10 Determination results of broflanilide in sediment in chironomid tests

[0116]

[0117]

[0118] Comparative Example 1

[0119] The artificial sediment with a chlorantraniliprole addition level of 0.1 mg / kg was detected by the detection method described in Example 1. The difference between this comparative example and Example 1 is only that the ethyl acetate extractant in step (3) of Example 1 was replaced with acetonitrile. The detection results and recovery rates are shown in Table 11.

[0120] Comparative Example 2

[0121] The artificial sediment with a chlorantraniliprole addition level of 0.1 mg / kg was detected by the detection method described in Example 1. The difference between this comparative example and Example 1 is only that the ethyl acetate extractant in step (3) of Example 1 was replaced with methanol. The detection results and recovery rates are shown in Table 11.

[0122] Comparative Example 3

[0123] The artificial sediment with a broflanilide addition level of 0.1 mg / kg was detected by the detection method described in Example 2. The difference between this comparative example and Example 2 is only that the acetonitrile solution of formic acid (the volume concentration of formic acid is 0.1%) in step (3) of Example 2 was replaced with acetonitrile. The detection results and recovery rates are shown in Table 11.

[0124] Comparative Example 4

[0125] The artificial sediment with a broflanilide addition level of 0.1 mg / kg was detected by the detection method described in Example 2. The difference between this comparative example and Example 2 is only that the acetonitrile solution of formic acid (the volume concentration of formic acid is 0.1%) in step (3) of Example 2 was replaced with methanol. The detection results and recovery rates are shown in Table 11.

[0126] Table 11 Test results of recovery rates when different extractants were used for the extraction and detection of chlorantraniliprole and broflanilide

[0127]

[0128] As shown in Table 11, two extraction solvents, acetonitrile and methanol, were compared. It was found that the recovery rate of broflanilide was less than 70% when acetonitrile was used as the extraction solvent. After adding 0.1% formic acid to the acetonitrile extraction solvent, the recovery rate of broflanilide met the requirements of the analytical method. Therefore, 0.1% formic acid in acetonitrile was selected as the extraction solvent for broflanilide for the experiment.

[0129] However, regardless of whether acetonitrile or methanol was used as the extraction solvent, the recovery rate of chlorantraniliprole was unqualified and relatively low. When ethyl acetate was used as the extractant, the recovery efficiency was relatively high.

[0130] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for detecting the concentrations of chlorantraniliprole and broflanilide in sediments, characterized in that, It includes the following steps: 1) Prepare standard solutions with gradient concentrations of the standard substance of the analyte using acetonitrile, and mix the standard solutions with gradient concentrations with artificial sediment to obtain spiked sediments with different analyte concentrations; 2) Sequentially sample, freeze-dry, crush, extract, adsorb and purify, centrifuge, nitrogen blow, and make up the volume of the spiked sediments with different analyte concentrations to obtain standard test solutions with different analyte concentrations; 3) Use a high-performance liquid chromatography-mass spectrometry (HPLC-MS) instrument to detect the standard test solutions with different analyte concentrations to obtain a concentration-peak area standard curve; 4) Sequentially sample, freeze-dry, crush, extract, adsorb and purify, centrifuge, nitrogen blow, and make up the volume of the sediment to be tested to obtain a test solution; Use a high-performance liquid chromatography-mass spectrometry (HPLC-MS) instrument to detect the test solution, and obtain the concentration of the analyte in the sediment to be tested according to the standard curve method; The analyte is chlorantraniliprole or broflanilide; Among them, when the analyte is chlorantraniliprole, the extraction in steps 2) and 4) independently uses ethyl acetate as the extractant; When the analyte is broflanilide, the extraction in steps 2) and 4) independently uses an acetonitrile solution of formic acid as the extractant, and the volume concentration of formic acid is 0.1%; 2. The method for detecting the concentrations of chlorantraniliprole and broflanilide in sediment according to claim 1, characterized in that, The preparation method of the artificial sediment in step 1) is: air-dry and crush sphagnum moss and mix it with water to form a suspension, and after domesticating the suspension, mix it with quartz sand, kaolin and deionized water to obtain artificial sediment; The pH value of the artificial sediment is 6.5 - 7.5, and the water content is 38 - 42% of the dry weight of the sediment; 3. The method for detecting the concentrations of chlorantraniliprole and broflanilide in sediment according to claim 2, wherein When the analyte is chlorantraniliprole, the content range of the analyte in the spiked sediment in step 1) is 0.01 - 1.0 mg / kg; When the analyte is broflanilide, the content range of the analyte in the spiked sediment in step 1) is 0.01 - 1.0 mg / kg; 4. A method for detecting the concentrations of chlorantraniliprole and broflanilide in sediment according to claim 2 or 3, characterized in that, When the analyte is chlorantraniliprole, the mobile phase of the high-performance liquid chromatography in the high-performance liquid chromatography-mass spectrometry instrument in step 3) is an acetonitrile-formic acid aqueous solution with a volume ratio of 10 - 90:85 - 15, where the volume concentration of the formic acid aqueous solution is 0.1%, the flow rate of the eluent is 0.5 mL / min, and the injection volume is 15 - 20 μL; 5. A method for detecting the concentrations of chlorantraniliprole and broflanilide in sediment according to claim 4, characterized in that, When the analyte is chlorantraniliprole, the ion source of the mass spectrometer in the high-performance liquid chromatography-mass spectrometry instrument in step 3) is an electrospray ionization source, the voltage of the ion source is 4200 - 5500 V, and the temperature of the ion source is 500 - 650 °C; 6. The method for detecting the concentrations of chlorantraniliprole and broflanilide in sediments according to claim 5, wherein When the analyte is broflanilide, the mobile phase of the high-performance liquid chromatography in the high-performance liquid chromatography-mass spectrometry instrument in step 3) has a volume ratio of 20 - 80:80 - 20 of acetonitrile-formic acid aqueous solution, where the volume concentration of formic acid in the formic acid aqueous solution is 0.1%, the flow rate of the eluent is 0.4 mL / min, and the injection volume is 5 - 20 μL; 7. A method for detecting the concentrations of chlorantraniliprole and broflanilide in sediments according to claim 6, characterized in that, When the analyte is broflanilide, the ion source of the mass spectrometer in the high-performance liquid chromatography-mass spectrometry instrument in step 3) is an electrospray ionization source, the voltage of the ion source is 4200 - 5500 V, and the temperature of the ion source is 450 - 650 °C; 8. A method for detecting the concentrations of chlorantraniliprole and broflanilide in sediments according to claim 7, characterized in that, When the analyte is chlorantraniliprole, the retention time is 1.4 min, and when the analyte is broflanilide, the retention time is 2.46 min.

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