GB/T 5009.19-2008Determination of organochlorine pesticide multiresidues in foods (English PDF)

1 Scope

Method One of this Standard specifies the determination of hexachlorocyclohexane (HCH), dichloro-diphenyl-dichloroethane (DDD), hexachlorobenzene, mirex, heptachlor, chlordane, aldrin, dieldrin, endrin, endosulfan, pentachloronitrobenzene in foods. Method Two specified the determination of residues of hexachlorocyclohexane, dichloro-diphenyl-trichloroethane (DDT) in foods.

Method One of this Standard is applicable to the analysis on alpha-HCH, hexachlorobenzene, beta-HCH, gamma-HCH, pentachloronitrobenzene, delta-HCH, pentachloroaniline, heptachlor, pentachlorophenyl sulfide, aldrin, oxychlorohydrin, epoxy heptachlor, 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 in meat, eggs, dairy foods and plants (including fats). Method Two is applicable to the determination of HCH, DDT residues in various foods.

The detection limit determined by Method One varies with the specimen matrix, see Annex A. Detection limit of Method Two. when the sampling amount is 2g, the final volume is 5mL, and the injection volume is 10µL, the detection limits for alpha-HCH, beta-HCH, gamma-HCH, and delta-HCH are sequentially as 0.038 µg/kg, 0.16 µg/kg, 0.047 µg/kg, and 0.070 µg/kg; the detection limits for p,p'-DDE, o,p'-DDT, p,p'-DDD, p,p'-DDT are sequentially as 0.23 µg/kg, 0.50 µg/kg, 1.8 µg/kg, 2.1 µg/kg. Method One -- Gas chromatography - Electron capture detector method

2 Principle

The organochlorine pesticide component in the specimen is extracted by organic solvent and purified by gel chromatography. Separate by capillary column gas chromatography. Detect by electron capture detector. Determine the chemical composition by retention time. Quantify by external standard method.

3 Reagents

3.1 Acetone (CH3COCH3). analytically pure, re-distilled.

3.2 Petroleum ether. boiling range of 30°C~60°C, analytically pure, re-distilled.

3.3 Ethyl acetate (CH3COOC2H5). analytically pure, re-distilled.

3.4 Cyclohexane (C6H12). analytically pure, re-distilled.

3.9 Pesticide standard products. alpha-HCH, HCB, beta-HCH, gamma-HCH, PCNB, delta-HCH, PCA, Heptachlor, PCPs, Aldrin, Oxychlordane, Heptachlorepoxide, trans-chlordane, alpha-endosulfan, cis-chlordane, p,p'-DDE, Dieldrin, Endrin, beta-endosulfan, p,p'-DDD, o,p'-DDT, Endrinaldehyde, Endosulfansulfate, p,p'-DDT, Endrinketone, Mirex, with a purity not less than 98%.

3.10 Preparation of standard solution. Accurately weigh or measure the appropriate amount of the above pesticide standard products. Dissolve with a small amount.

4 Apparatus

4.1 Gas chromatograph (GC). equipped with electronic capture detector (ECD).

4.3 Automatic gel chromatography system. with a fixed wavelength (254nm) UV detector for optional use.

4.4 Rotary evaporator.

4.5 Tissue homogenizer.

4.6 Oscillator.

4.7 Nitrogen concentrator.

5 Analysis steps

6 Result calculation

The content of each pesticide in the specimen is calculated according to formula (1).

7 Precision

The absolute difference between two independent determinations obtained under repeatability conditions shall not exceed 20% of the arithmetic mean. See Annex C for the method to determine the uncertainty.

8 Principle

After HCH, DDT in the specimen are extracted and purified, use gas chromatography to determine. Compare with the standard and quantify.

Electron capture detector is extremely sensitive to compounds with strong negative electrodes.

9 Reagents

9.1 Acetone (CH3COCH3). analytically pure, re-distilled.

9.2 N-hexane (n-C6H14). analytically pure, re-distilled.

9.3 Petroleum ether. boiling range of 30°C~60°C, analytically pure, re-distilled.

9.6 Anhydrous sodium sulfate (Na2SO4). analytically pure.

9.7 Sodium sulfate solution (20 g/L).

10 Apparatus

10.1 Gas chromatograph. with electron capture detector.

10.2 Rotary evaporator.

10.6 Centrifuge.

10.7 Plant sample crusher. […]