GB 23200.100-2016Food safety national standard -- Determination of permethrin residues in royal jelly -- Gas chromatography (English PDF)

4.1 Reagents

4.1.1 ether (C4H10O). pure chromatography.

4.1.2 n-hexane (C6H14). pure chromatography.

4.1.3 Acetone (C3H6O). Chromatographic pure.

4.1.4 Sodium chloride (NaCl).

4.1.5 anhydrous sodium sulfate (Na2SO4). 650 °C burning 4h, in the dryer to cool to room temperature, stored in a sealed bottle in reserve.

4.2 Standards

4.2.1 Bifenthrin, fenpropathrin, cyhalothrin, permethrin, cypermethrin,, fenpropathrin, fenvalerate, Deltamethrin standard substance. purity >=99%, see Appendix A.

4.3 Standard solution preparation

4.3.1 Bifenthrin, fenpropathrin, cyhalothrin, permethrin, cypermethrin,, fenpropathrin, Pyrethrin, deltamethrin standard solution. accurately weighed the appropriate amount of standard material, with n-hexane dubbed the concentration of 100 g/mL standard stock solution.

According to the need to use n-hexane diluted to the appropriate concentration of mixed standard working solution. Store in 4 °C refrigerator.

4.4 Materials

4.4.1 Florisil Solid Phase Extraction Column. (6 mL, 1 g) or equivalent. Use a 10 mm high anhydrous sodium sulphate layer in the front column 5 mL n-hexane elution activated solid phase extraction column.

7.1 Extraction

Weigh 2 g sample (accurate to 0.01 g) in 50 mL centrifuge tube, add 10 mL water vortex mixed 1 min, standing 5 min. Add 20 ML n-hexane acetone (1 1, volume ratio) mixed solvent, vortex mixed for 1 min, centrifuged at 4000 r/min for 3 min, the upper organic phase Transferred into the concentrated bottle. Add 10 mL of n-hexane acetone (1 1, volume ratio v/v) mixed solvent, repeated extraction time, Combined with the upper organic phase, below 45 °C in the water bath under reduced pressure to near dry, to be purified.

7.2 Purification

The residue in the concentrated flask was washed twice with 3 mL of n-hexane and transferred to a Florisil solid phase extraction column. With 5 mL of n-hexane the eluate was discarded and eluted with 10 mL of n-hexane + diethyl ether (9 + 1, v/v) mixed solvent. The eluate was collected in 10 mL of glass Centrifuge tube, in the 45 °C water bath with nitrogen blowing slowly blown to dry, with n-hexane dissolved and set to 0.5 mL, for gas chromatography.

7.3 Determination

7.3.1 Gas Chromatographic Reference Conditions

A) Column. HP-50 quartz capillary column, 30 m x 0.32 mm (inner diameter) x 0.25 µm (film thickness), or equivalent;

B) column temperature. 70 °C for 1 min, at 20 °C/min heating rate rose to 270 °C, keep 1 min, at 2 °C / Min heating rate rose to 280 °C, keep 10 min;

C) Inlet temperature. 270 ° C;

D) Tester temperature. 325 ° C;

E) Carrier gas. nitrogen, purity 99.999%, flow rate 2.0 mL/min, tail blow 60 mL/min;

F) Injection volume. 2 µL;

G) Injection method. splitless injection, open valve time 0.75 min.

7.3.2 Chromatographic determination

Depending on the amount of various pyrethrins in the sample solution, a standard working solution with similar levels is selected. Standard working solution and sample in a variety of pyrethroids should be within the linear range of the instrument. Standard working solution and sample volume and other volume interspersed injection determination. Under the above chromatographic conditions the retention time of bifenthrin was about 12.9 min; the retention time of fenpropathrin was about 13.6 min; the retention time of cyhalothrin was 14.0 min; the retention time of the isomers of permethrin was about 16.0, 16.2 min; the retention time of the cyfluthrin was about 16.6 Min, 16.7 min, 16.9 min; the retention time of cypermethrin is about 17.5 min, 17.6 min, 17.8 min;

The retention time of the isomers of cypermethrin was about 18.6 min and 18.8 min. The retention time of the fenvalerate was about 19.9 min, 20.5 min; deltamethrin retention time is about 23.0 min. The chromatogram of the standard is shown in Appendix B, Figure B.1.

7.4 Blank test

In addition to the sample, according to the above determination steps.

10.1 Quantitation limits

The quantification limit of this method is. 0.01 mg/kg.

10.2 Recovery rate

The experimental data on the concentration and recovery of the sample are given in Appendix C.

Appendix A

(Informative)

9 kinds of pyrethroid pesticides in English common name, chemical formula, CAS No. information

Table A.1 9 kinds of pyrethroid pesticides in English common name, chemical formula, CAS No. information

Chinese generic name English generic name chemical formula CAS number Bifenthrin C23H22ClF3O2 82657-04-3 Fenpropathrin C22H23NO3 39515-41-8 Enriched cyhalothrin Lambda-Cyhalothrin C23H19ClF3NO3 91465-08-6 Permethrin C21H20Cl2O3 52645-53-1 Cyfluthrin C22H18Cl2FNO3 68359-37-5 Cypermethrin C22H19Cl2NO3 97955-44-7 Fenpropathrin tau-fluvalerate C26H22ClF3N2O3 69409-94-5 Fenvalerate C25H22ClNO3 51630-58-1 Deltamethrin C22H19Br2NO3 52918-63-5 Appendix B (Informative) Chromatogram of standard substance

Figure B.1 Chromatogram of 9 Pyrethroid Pesticide Standards

1. Bifenthrin 2. Fenpropathrin 3. Highly effective cyhalothrin 4. Permethrin I 5. Permethrin II 6. Cyfluthrin I 7. Cyfluthrin II 8. Cyfluthrin III 9. Cypermethrin I 10. Cypermethrin II Cypermethrin III 12. Fenpropathrin I 13. Fenpropathrin II 14. Fenvalerate I 15. Fenvalerate II 16 deltamethrin Appendix C (Informative) Sample concentration and recovery of the experimental data

Table C.1 Experimental data on the concentration and recovery of the sample

Pesticide name Add concentration (mg/kg) Recovery rate range% Precision range Pesticide name Add concentration (mg/kg) Recovery rate range% Precision range% Bifenthrin 0.01 76.0 to 91.0 10.6 Cypermethrin 0.01 77.2 to 109 9.6 0.02 70.0 to 97.5 8.7 0.02 77.5 to 110 8.4 0.05 77.8 ~ 103 8.1 0.05 73.6 ~ 106 12.3 Fenpropathrin 0.01 78.4 to 101 11.6 Fenpropathrin 0.01 72.4 to 99.8 7.4 0.02 79.5 to 107 10.8 0.02 77.5 to 109 6.9 0..05 80.4 to 109 7.2 0.05 73.0 to 106 11.3 Cyhalothrin 0.01 78.8 to 108 13.4 fenvalerate 0.01 71.5 to 104 8.2 0.02 78.0 to 104 8.9 0.02 78.5 to 106 9.6 0.05 77.6 to 104 7.6 0.05 76.8 to 103 7.2 Permethrin 0.01 78.3 ~ 97.4

12.1 Deltamethrin 0.01 72.4 ~ 110 11.6

0.02 80.8 ~

13.2 0.02 77.5 to 112 10.0 0.05 76.4 ~ 9.5 0.05 78.8 to 108 8.9 Cyfluthrin 0.01 71.3 ~ 14.0 0.02 78.5 ~ 13.1 0.05 73.2 ~ 8.9 Appendix D (Normative appendix) Laboratory repeatability requirements

Table D.1 Laboratory repeatability requirements

Measured component content Mg/kg Precision <=0.001 36 > 0.01 > 1 14 Appendix E (Normative appendix) Inter-laboratory reproducibility requirements

Table E.1 Inter-laboratory reproducibility requirements

Measured component content Mg/kg Precision <=0.001 54 > 0.01 > 1 19