GB/T 5009.162-2008Determination of organochlorine pesticide and pyrethroid pesticide multiresidues in animal original foods (English PDF)

1 Scope

The method-1 of this standard specifies the determination method for the chromatography-mass spectrometry (GC-MS) of benzenehexachloride, DDT, hexachlorobenzene, heptachlor, heptachlor epoxide, chlordane, aldrin, dieldrin, endrin, mirex, pentachloronitrobenzene, endosulfan, fenson, allethrin, dichlorophenyl benzensulfonate, tetramethrin, fenpropathrin, permethrin, cypermethrin, fenralerate, deltamenthrin.

The method-2 of this standard spcifies the determination method of gas chromatography-electron capture device (GC-ECD) for the benzenethexzchloride, DDT, pentachloronitrobenzene, heptachlor, heptachlor epoxide, aldrin, dieldrin, fenson, ovex, tetramethrin, permethrin, cypermethrin, alpha-fenralerate, deltamethrin.

The method-1 of this standard applies to the confirmation analysis of alpha-benzenehexachloride, hexachlorobenzene, beta-benzenehexachloride, gamma-benzenehexachloride, pentachloronitrobenzene, delta-benzenehexachloride, pentachloraniline, heptachlor, pentachlorophenyl sulfide, aldrin, oxychlordane, heptachlor epoxide, trans-chlordane, alpha-endosulfan, cis-chlordane, p,p'-DDE, dieldrin, endrin, beta-endosulfan, p,p'-DDD, o,p'-DDT, endrin aldehyde, endosulfan sulfate, p,p'-DDT, endrin ketone, mirex, fenson, allethrin, 2,4-dichlorophenyl benzensulfonate, ovex, tetramethrin, fenpropathrin, permethrin, cypermethrin, fenralerate, deltamenthrin in meat, egg, milk food, fat (including vegetable oil).

The method-2 of this standard applies to the analysis of 20 commonly-used organochlorine pesticides and pyrethroid pesticide residues such as alpha-benzenehexachloride, beta-benzenehexachloride, gamma-benzenehexachloride, delta-benzenehexachloride, pentachloronitrobenzene, heptachlor, heptachlor epoxide, aldrin, dieldrin, fenson, ovex, p,p'-DDE, p,p'-DDD, o,p'-DDT, p,p'-DDT, tetramethrin, permethrin, cypermethrin, alpha-fenralerate, deltamenthrin.

The detection limits (µg/kg) of various pesticides in method-1 of this standard are: alpha-benzenehexachloride 0.20; hexachlorobenzene 0.20; beta-benzenehexachloride 0.20; gamma-benzenehexachloride 0.20; pentachloronitrobenzene 0.50; delta-benzenehexachloride 0.20; pentachloraniline 0.50; heptachlor 0.50; pentachlorophenyl sulfide 0.50; aldrin 0.50; oxychlordane 0.20; heptachlor epoxide 0.50; trans-chlordane 0.20; alpha-endosulfan 0.50; cis-chlordane 0.20; p,p'-DDE 0.20; dieldrin 0.20; endrin 0.50;

beta-endosulfan 0.50; p,p'-DDD 0.20; o,p'-DDT 0.20; endrin aldehyde 0.50; endosulfan sulfate 0.50; p,p'-DDT 0.20; endrin ketone 0.50; mirex 0.20; fenson 0.50; allethrin 0.50; 2,4-dichlorophenyl benzensulfonate 0.50; ovex 0.50; tetramethrin 1.00; fenpropathrin 1.00; permethrin 1.00; cypermethrin 2.00; fenralerate 2.00; deltamenthrin 2.00.

The detection limits (µg/kg) of various pesticides in method-2 of this standard are: alpha-benzenehexachloride 0.25; beta-benzenehexachloride 0.50; gamma-benzenehexachloride 0.25; delta-benzenehexachloride 0.25; pentachloronitrobenzene 0.25; heptachlor 0.50; heptachlor epoxide 0.50; aldrin 0.25; dieldrin 0.50; fenson 1.25; ovex 1.25; p,p'-DDT 0.50; o,p'-DDT 0.50; p,p'- DDE 0.60; p,p'-DDD 0.75, tetramethrin 12.50; permethrin 7.50; cypermethrin 2.00; alpha-fenralerate 2.50; deltamenthrin 2.50.

2 Principles

In the homogeneous sample solution, quantitatively add the stable isotope internal standard of 13C-hexachlorobenzene and 13C-mirex. It is oscillated and extracted by organic solvent, purified by gel chromatography. It is determined by the gas chromatography-mass spectrometry (GC-MS) with selective ion monitoring, quantified by internal standard method.

3 Reagents

3.1 Acetone (CH3COCH3): Analytically pure, re-steamed.

3.2 Petroleum ether: Boiling range 30 °C ~ 60 °C, analytical pure, re-steamed.

3.3 Ethyl acetate (CH3COOC2H5): Analytically pure, re-steamed.

3.4 Cyclohexane (C6H12): Analytically pure, re-steamed.

3.5 n-hexane (n-C6H14): Analytically pure, re-steamed.

3.6 Sodium chloride (NaCl): Analytically pure.

3.7 Anhydrous sodium sulfate (Na2SO4): Analytically pure. Place the anhydrous 13C6-hexachlorobenzene (6 mg/L) and 5 mL of 13C10-mirex (6 mg/L). Add 40 mL of acetone. Shake it for 30 min. The rest of the operation is the same as the operation of eggs in 5.2.1 starting from "Add 6 g of sodium chloride".

5 Analytical procedures

5.2.4 Fat: Weigh 1 g (accurate to 0.01 g). Add 5 µL of 13C6-hexachlorobenzene (6 mg/L) and 5 mL of 13C10-mirex (6 mg/L). Add 30 mL of petroleum ether. Shake it for 30 min. Transfer all the organic phase into a rotary evaporation flask.

Concentrate it to about 1 mL. Add 2 mL of ethyl acetate-cyclohexane (1 + 1) solution for re-concentration. Repeat this operation for 3 times to concentrate it to about 1 mL, to prepare for use by gel chromatographic purification. Or otherwise transfer the concentrated solution into the sample-injection test-tube of the fully-automatic gel permeation chromatography system. Use ethyl acetate - cyclohexane (1 + 1) solution to rinse the rotary evaporation flask for several times. Combine the rinsing solution into the test-tube. Make its volume reach to 10 mL.

6 Calculation of results

Where:

X - The content of each pesticide component in the specimen, in micrograms per kilogram (µg/kg);

A - The mass of the target compound corresponding to the area ratio of the chromatographic peak of the specimen to the internal standard's chromatographic peak, in nanograms (ng);

f - The dilution factor of the sample solution;

m - The size of the sample, in grams (g).

For the calculation results, it retains three significant figures.

7 Precision

The absolute difference between two independent determinations obtained under repetitive conditions shall not exceed 20% of the arithmetic mean. The method uncertainty is as shown in Appendix C.

8 Principle

The sample is extracted, purified, concentrated, constant-volume, separated by capillary column gas chromatography, detected by electron capture detector, qualitative-determined by the retention time, quantified by external standard method. Peak order: alpha-HCH, beta-HCH, gamma-HCH, pentachloronitrobenzene, delta-HCH, heptachlor, aldrin, fenson, heptachlor epoxide, ovex, dieldrin, p, p'-DDE, p, p'- DDD, o,p'-DDT, p,p'-DDT, tetramethrin, permethrin, cypermethrin, alpha-fenralerate, deltamethrin.

9 Reagents

9.1 Acetone: Re-steamed.

9.2 Dichloromethane: Re-steamed.

9.3 Ethyl acetate: Re-steamed.

10 Instruments

10.1 Gas Chromatograph: It is equipped with electron capture detector, capillary column.

10.2 Rotary evaporator.

11 Analytical procedures