HJ 961-2018Soil and sediment - Determination of carbamate pesticides - High performance liquid chromatography-triple quadrupole mass spectrometry (English PDF)

Foreword

To implement the "Environmental Protection Law of the People's Republic of China", protect the ecological environment, protect human health, regulate soil and sink this standard is established for the measurement method of carbamate pesticides in the product.

This standard specifies high performance liquid chromatography-triple quadrupole for the determination of 15 carbamate pesticides in soil and sediment.

Mass spectrometry.

Appendix A of this standard is a normative appendix, and Appendix B is an informative appendix.

This standard is the first release.

This standard is formulated by the Environmental Monitoring Department and the Science and Technology Standards Department.

This standard was drafted. Zhejiang Environmental Monitoring Center.

This standard is verified by. Jiangsu Environmental Monitoring Center, Zhejiang Zhoushan Marine Ecological Environment Monitoring Station, Hangzhou Environment Monitoring Center Station, Suzhou Environmental Monitoring Center, Shaoxing Environmental Monitoring Center Station and Jiaxing Environmental Protection Monitoring Station.

This standard is approved by the Ministry of Ecology and Environment on July 29, 2018.

This standard has been implemented since January 1, 2019.

This standard is explained by the Ministry of Ecology and Environment.

1 Determination of soil and sediment carbamate pesticides

High performance liquid chromatography-triple quadrupole mass spectrometry Warning. The solvents and standard solutions used in the experiment are harmful to human health. The solution preparation and sample preparation process should be Wear in a fume hood; wear protective equipment as required to avoid direct contact with skin and clothing.

1 Scope of application this standard specifies high performance liquid chromatography-triple quadrupole for the determination of 15 carbamate pesticides in soil and sediment.

Mass spectrometry.

This standard applies to soil and sediments such as chlorpyrifos, methomyl, dioxin, aldicarb, chlorpyrifos, carbofuran, and 15 kinds of ammonia such as chlorpyrifos, carbaryl, ethyl thiophene, anti-蚜威, isoprocarb, zhongdingwei, methylthiocarb, chlorpyrifos and cotton ring Determination of carbamate pesticides.

When the sample volume is 10 g, the sample volume is 1.0 ml, and the injection volume is 1.0 µl, 15 carbamate farmers the detection limit of the drug is 1 to 2 µg/kg, and the lower limit of determination is 4 to 8 µg/kg. See Appendix A for details.

2 Normative references

This standard refers to the following documents or their terms. For undated references, the valid version applies to this standard.

GB 17378.3 Marine monitoring specification Part 3. Sample collection, storage and transport GB 17378.5 Marine monitoring specification Part 5. Sediment analysis HJ 494 Water Quality Sampling Technical Guidance HJ 613 Determination of dry matter and moisture in soils - Gravimetric method HJ 783 Extraction of soil and sediment organic matter by pressurized fluid extraction HJ/T 166 Technical Specifications for Soil Environmental Monitoring

3 Principle of the method

The carbamate pesticide in the soil or sediment is extracted by organic solvent, purified by solid phase extraction column, concentrated, and made up to volume.

It was determined by high performance liquid chromatography-triple quadrupole mass spectrometry and quantified by internal standard method according to retention time and characteristic ion characterization.

4 Interference and elimination

Substances with similar retention times and molecular ion peaks interfere with the determination by changing the mobile phase and changing the quantification Ion pairs or high resolution mass spectrometry to eliminate interference.

25 Reagents and materials

Analytically pure reagents in accordance with national standards were used for analysis, unless otherwise stated.

The pure water of the standard.

5.1 Methanol (CH3OH). liquid chromatography grade.

5.2 Dichloromethane (CH2Cl2). liquid chromatography grade.

5.3 Ammonium acetate (CH3COONH4). excellent grade pure.

5.4 anhydrous sodium sulfate (Na2SO4).

The muffle furnace was fired at 450 ° C for 4 h, cooled slightly, and placed in a desiccator for use.

5.5 Methanol-dichloromethane mixed solvent. 1 2.

Mix with methanol (5.1) and dichloromethane (5.2) in a volume ratio of 1.2.

5.6 Methanol-dichloromethane mixed solvent. 19.

Mix with methanol (5.1) and dichloromethane (5.2) in a volume ratio of 1.9.

5.7 Ammonium acetate solution. c(CH3COONH4) = 5 mmol/L.

Take 192.5 mg of ammonium acetate (5.3) and dissolve to a volume of 500 ml with water.

5.8 Methanol-ammonium acetate mixed solution. 2 3.

Mix with methanol (5.1) and ammonium acetate solution (5.7) in a 2.3 volume ratio.

5.9 Standard stock solution of carbamate pesticide. rho=100 mg/L.

Purchase commercially available certified standard solutions directly and store them in accordance with the standard solution certificate.

5.10 Standard use solution for carbamate pesticides. rho=10 mg/L.

Take 500 µl of carbamate pesticide standard stock solution (5.9) in a 5 ml volumetric flask and dilute to volume with methanol (5.1).

Mix well, place in a -18 ° C refrigerator, sealed, protected from light, and the shelf life is 6 months.

5.11 Standard internal standard stock solution. rho=100 mg/L.

Directly purchase commercially available carbaryl-D7 and methomyl-D3 certified standard solutions, and store them according to the standard solution certificate.

5.12 Internal standard use solution. rho=10 mg/L.

Take 500 µl of internal standard stock solution (5.11) in a 5 ml volumetric flask, dilute to volume with methanol (5.1), mix and place.

-18 ° C refrigerator, sealed, protected from light, the shelf life is 6 months.

5.13 Solid phase extraction column. Graphitized carbon black/N-propyl ethylene diamine composite filler column (500 mg/6 ml) or other properties A similar solid phase extraction column.

5.14 Diatomaceous earth. 0.6 to 0.9 mm (30 to 20 mesh).

5.15 Quartz sand. 150 ~ 830 µm (200 ~ 100 mesh).

The muffle furnace was fired at 450 ° C for 4 h, cooled slightly, and placed in a clean dryer for later use.

5.16 Filter. 0.22 µm PTFE or other equivalent material.

5.17 Nitrogen. purity >= 99.99%.

5.18 Argon. purity >= 99.99%.

6 Instruments and equipment

6.1 High Performance Liquid Chromatography - Triple Quadrupole Mass Spectrometer.

36.1.1 Mass spectrometer. Triple quadrupole mass spectrometer with electrospray ion source with multiple reaction monitoring.

6.1.2 Chromatograph. Gradient elution function.

6.1.3 Column. Low-bond octadecylsilane-bonded silica gel column with a particle size of 1.7 µm and a column length of 50 mm.

The inner diameter is 2.1 mm. Other columns with similar properties that meet the analytical requirements can also be used.

6.2 Freeze dryer.

6.3 Extraction device. pressurized fluid extractor (with extraction tank below 50 ml), Soxhlet extraction device, automatic Soxhlet extraction Instrument or other equivalent extraction device.

6.4 Concentrator. Nitrogen blown concentrator, rotary evaporator or other equivalent equipment.

6.5 Analytical balance. The sensitivity is 0.01 g.

6.6 Common instruments and equipment used in general laboratories.

7 samples

7.1 Sample collection and preservation Collect and store soil samples in accordance with the relevant requirements of HJ/T 166, and collect water bodies according to the relevant requirements of HJ 494 Samples of marine sediments were collected according to the relevant requirements of GB 17378.3. After sample collection, seal and avoid at 0~4°C Light preservation, extraction completed within 7 days.

7.2 Preparation of samples Remove foreign matter (branches, leaves, stones, etc.) from the sample and mix the sample thoroughly. If the sample has a high moisture content, it should be dried first with a freeze dryer (6.2). Weigh two samples of approximately 10 g (accurate to 0.01 g).

One sample of the soil sample is used to determine the dry matter content; the other is used for extraction. When using pressurized fluid extraction, add Add appropriate amount of diatomaceous earth (5.14) and put it into the extraction tank. When using Soxhlet extraction, add an appropriate amount of anhydrous sodium sulfate (5.4) and load Extract the tube.

One sample of the sediment is used to determine the water content; the other is used for extraction, and the extraction method is based on the soil sample.

7.3 Determination of moisture the dry matter content of the soil samples was determined according to HJ 613, and the moisture content of the sediment samples was determined in accordance with GB 17378.5.

7.4 Preparation of samples

7.4.1 Extraction

7.4.1.1 Pressurized fluid extraction the carbamate pesticide in the sample was extracted with a methanol-dichloromethane mixed solvent (5.5) at a pressure of 10.34 Mpa.

The extraction temperature is 80oC, the heating time is 5 min, the static extraction time is 5 min, the flushing amount is 80%, and the nitrogen is purged for 60 s after extraction.

Cycle extraction 3 times. Or set and optimize the extraction conditions according to HJ 783.

7.4.1.2 Soxhlet extraction Place the filter cartridge in the Soxhlet extractor return tube and add.200 ml methanol-dichloromethane mixed solvent to the round bottom solvent bottle.

4 (5.5), extracted for 12 h, and the reflux rate is controlled at 4-6 times/h. After the extraction is completed, the round bottom solvent bottle is taken out and concentrated.

Note. Other equivalent extraction methods can be used if verified.

7.4.2 Concentration

The extract (7.4.1) was concentrated to nearly 1.0 ml with a concentrating device (6.4) to be purified.

7.4.3 Purification

Activate the solid phase extraction column (5.13) at a rate of 2 ml/min with 5.0 ml of methanol-dichloromethane mixed solvent (5.6).

Transfer the concentrate (7.4.2) to the column head just before the filler is exposed to air, before the filler is about to be exposed to air.

The extraction column was eluted with 5.0 ml of a methanol-dichloromethane mixed solvent (5.6), and the eluate was collected in a graduated tube.

Note. When using different batches of extraction column to purify the sample, the amount of elution solvent should be determined experimentally.

7.4.4 Concentration after purification Concentrate the eluate (7.4.3) below 30oC to near-dry with a nitrogen blow concentrator (6.4), and add 20 µl of internal standard.

Liquid (5.12), make up to 1.0 ml with methanol-ammonium acetate mixed solution (5.8), filter membrane (5.16), to be tested.

The treated samples should be stored frozen in a refrigerator below -18 ° C and analyzed in 30 days.

7.5 Preparation of blank samples A blank sample was prepared by replacing the actual sample with quartz sand (5.15) in the same manner as in sample preparation (7.4).

8 Analysis steps

8.1 Reference measurement conditions

8.1.1 Chromatographic conditions Mobile phase. mobile phase A methanol (5.1), mobile phase B ammonium acetate solution (5.7), gradient elution procedures are shown in Table 1. flow Speed. 0.2 ml/min; injection volume. 1.0 µl; column temperature. 45oC.

Table 1 Gradient elution procedure

Time (min) mobile phase A (%) mobile phase B (%) 5.0 99 1 5.5 99 1 7.0 40 60

8.1.2 Mass spectrometry conditions Electrospray source, positive ion mode, capillary voltage. 3000 V, desolvation gas temperature. 350oC, source temperature. 110oC, Desolvent gas flow. 500 ml/min, cone flow. 50 ml/min. The detection method is multi-reaction monitoring. See the specific conditions.

5 Table 2.

Note. For different mass spectrometers, the parameters may vary and the mass spectrometry parameters should be optimized to the optimum before measurement.

Table 2 Target multiple reaction monitoring conditions

Numbered compound monitoring ion pair (m/z) cone voltage (V) collision energy (V) 1 kill line 237.1 >71.9* 12 10 237.1 >90.1 12 12 2 灭多威 163.4 >88.4* 15 9 163.4 >106.0 15 10

3 Dioxin

224.4 >123.4* 25 15

224.4 >167.1 25 13

4 Aldicarb

208.5 >116.3* 10 10

208.5 >88.9 10 8

5 worms

224.4 >167.4* 18 9

224.1 >109.1 18 10

6 grams of Budweiser 222.4 >165.4* 25 15 222.4 >123.0 25 14

7 Killer

210.5 >111.3* 20 13

210.5 >168.1 20 12

8 carbaryl

202.4 >145.2* 20 18

202.4 >127.1 20 16

9 ethion

226.4 >107.2* 15 9

226.4 >164.1 15 12

10 anti-random

239.5 >72.4* 18 19

239.5 >182.2 18 18

11 Isoprocarb

194.5 >95.0* 15 12

194.5 >137.2 15 12

12 Zhong Dingwei

208.4 >95.3* 15 12

208.4 >152.0 15 15

13 methylthiocarb

226.4 >169.4* 20 13

226.4 >121.0 20 12

14 murder

208.4 >109.4* 20 15

208.4 >151.2 20 16

15 Cotton Bell

400.5 >238.2* 12 8

400.5 >91.1 12 10

16 灭多威-D3 166.1 >88.1* 15 9

17 Carbaryl-D7 209.0 >152.1* 20 18 Note. Band * is a quantitative ion pair.

8.1.3 Correction of the mass spectrometer Perform mass spectrometer mass and resolution calibration according to the instrument manual, and test after the instrument performance is normal.

79 Calculation and representation of results

9.1 Qualitative analysis According to the qualitative analysis of retention time, under the same experimental conditions, the retention time of the target in the sample and the standard solution for the retention time of the standard, the deviation should be less than or equal to 0.1 min. S/N of the target peak (the letter of the target in the instrument) no./Instrument Noise) is greater than or equal to 3. The relative abundance of a certain component of a sample in the sample samK and the standard solution close to the concentration the relative abundance of the neutral ionic ions stdK is compared, and the deviation is in accordance with Table 3, and it can be determined that the target is present in the sample.

The total ion chromatograms of 15 carbamate pesticides and 2 internal standards are shown in Figure 1.

The relative abundance of a certain component of the sample, samK, is calculated according to formula (3).

Sam x= A

Where. samK - the relative abundance of a component of a sample in the sample, %;

2A - the peak area (or peak height) of a qualitative ion pair of a component in the sample;

1A - The peak area (or peak height) of a given pair of quantitative ions in a sample.

The relative abundance of a certain component of a standard solution, stdK, is calculated according to formula (4).

Std x=

Std

Std

Where. stdK - the relative abundance of a component of a standard solution, %;

2stdA - the peak area (or peak height) of a qualitative ion pair of a component in a standard solution;

1stdA—The peak area (or peak height) of a quantitative ion pair of a component in a standard solution.

Table 3 Maximum allowable deviation of relative ion abundance in qualitative confirmation/%

Indicator evaluation criteria stdK stdK >50 20 238.2 2.26e5 5.09 5.11 5.14 180301carbamate--137 15. MRM of 1 Channel ES 208.4 > 109.4 4.17e6 4.44 180301carbamate--137 14. MRM of 1 Channel ES 226.4 > 169.4 1.96e6 4.31 180301carbamate--137 13. MRM of 1 Channel ES 208.4 > 95.3 5.07e6 4.23 180301carbamate--137 12. MRM of 1 Channel ES 194.5 > 95 3.38e6 3.73 Time 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 180301carbamate--137 5. MRM of 1 Channel ES 208.5 > 116.3 9.71e5 2.47 180301carbamate--137 4. MRM of 1 Channel ES 224.4 > 123.4 4.21e5 1.64 180301carbamate--137 3. MRM of 1 Channel ES 163.4 > 88.4 9.77e5 1.00 180301carbamate--137 2. MRM of 2 Channels ES 209 > 152.1 2.16e5 3.26 180301carbamate--137 2. MRM of 2 Channels ES 166.1 > 88.1 3.37e5 1.00 180301carbamate--137 1. MRM of 1 Channel ES 237.1 > 71.9 3.55e5 0.85 Time 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20 4.40 4.60 4.80 5.00 5.20 5.40 5.60 5.80 6.00 180301carbamate--137 11. MRM of 1 Channel ES 239.5 > 72.4 5.83e6 3.69 180301carbamate--137 10. MRM of 1 Channel ES 226.4 > 107.2 2.31e6 3.48 180301carbamate--137 9. MRM of 1 Channel ES 202.4 > 145.2 1.15e6 3.30 180301carbamate--137 8. MRM of 1 Channel ES 210.5 > 111.3 2.72e6 3.05 180301carbamate--137 7. MRM of 1 Channel ES 222.4 > 165.4 4.09e6 3.11 180301carbamate--137 6. MRM of 1 Channel ES 224.4 > 167.4 1.60e6 3.061.63