GB 23200.106-2016Food safety national standard -- Determination of residual residues in meat and meat products -- Gas chromatographic method (English PDF)

4.1 Reagents

4.1.1 Cyclohexane (C6H12). Chromatographic Purification.

4.1.2 Ethyl acetate (C4H8O2). Chromatographic purity.

4.1.3 n-hexane (C6H14). chromatographic purity.

4.1.4 Toluene (C7H8). Chromatographic pure.

4.1.5 anhydrous sodium sulfate (Na2SO4). before burning at 650 °C for 4 h, stored in a dryer, cooling and standby.

4.2 Reagent preparation

4.2.1 Cyclohexane-ethyl acetate mixed solvent (1 +1, volume ratio). take 100mL cyclohexane, add 100mL ethyl acetate, shake spare.

4.3 Standards

4.3.1 Propoxur; C11H15NO3; CAS No.114-26-1). purity >=99%.

4.4 Standard solution preparation

4.4.1 Residue Granville standard reserve solution. accurately weighed the amount of the standard material (accurate to 0.1 mg), with toluene concentration of 1.0 mg/mL of standard stock solution. Store in 4 °C refrigerator.

4.4.2 Propoxurized standard working solution. According to the testing requirements, respectively, the above standard stock solution with n-hexane diluted to the appropriate concentration of the standard Quasi-working solution. Store in 4 °C refrigerator.

4.5 Materials

4.5.1 Filtration. 0.45 µm, organic.

4.5.2 anhydrous sodium sulfate column. in the cylindrical funnel (diameter 1.5 cm), containing about 5 cm high anhydrous sodium sulfate.

6.1 Preparation of the sample

Samples were minced with a meat grinder, and the sample samples were carried out in accordance with GB 2763 Appendix A, mixed thoroughly, dashed to a ratio of not less than 500 g, Into the cleaning container, sealed, marked mark.

6.2 Storage of samples

The sample was stored at -18 ° C or lower.

7.1 Extraction

Weigh 10 g of sample (accurate to 0.01 g) in a 100 mL centrifuge tube containing 20 g of anhydrous sodium sulfate, add 30 mL of cyclohexane-acetic acid Ethyl ester mixed solvent, homogenized at 15 000 r/min homogeneous extraction 1.5 min, centrifuged at 3000 r/min for 3 min. Supernatant is filled with an anhydrous sodium sulfate canister was collected in 100 mL pear bottles. The residue was extracted with 30 mL of cyclohexane-ethyl acetate mixed solvent the combined extracts were washed twice and the anhydrous sodium sulphate column was washed with a small amount of cyclohexane-ethyl acetate mixed solvent. The extract was washed with water at 40 ° C Turn to about 2 mL, to be purified.

7.2 Purification

7.2.1 Gel Permeation Chromatography Instrument Conditions

A) Purification column. 400 mm × 25 mm, built with BIO-Beads S-X3 packing or equivalent.

B) Mobile phase. cyclohexane-ethyl acetate (1 + 1, volume ratio).

C) Flow rate. 5 mL/min.

D) Injection volume. 5 mL.

E) Start collection time. 1.200 s.

F) End of collection time. 1 800 s.

7.2.2 Purification

The concentrated extract (7.1) was transferred to a 10 mL graduated centrifuge tube and washed several times with a cyclohexane-ethyl acetate mixed solvent Shaped bottles, combined lotion and constant volume to the scale. After centrifugation at 4 000 r/min for 5 min, the supernatant was filtered through a 0.45 µm organic phase filter into gel permeation in the chromatograph of the chromatograph. Purified with a gel permeation chromatograph and collected effluent from 1.200 s to 1 800 s. The effluent was blown with a nitrogen blower Dry, add 1.0 mL n-hexane dissolved, mixed, gas chromatographic determination.

7.3 Determination

7.3.1 Chromatographic determination of reference conditions

A) Column. HP-5, 30 m x 0.32 mm (id), film thickness 0.25 µm, or equivalent.

B) column temperature. the initial temperature of 100 °C, keep 0.5min; at 10 °C/min speed up to 280 °C, keep 10min.

C) Carrier gas (N2). 1.5 mL/min.

D) Hydrogen (H2). 3.0 mL/min.

E) Air. 60 mL/min.

F) Detector temperature. 280 ° C.

G) Inlet temperature. 250 ° C.

H) Injection volume. 1 µL.

I) Injection method. no split injection, 1.5 min after opening the diverter valve.

GB/T 23200.106-2016

7.3.2 Chromatographic determination

According to the content of the product in the sample, select the appropriate concentration of the standard working solution and the sample to be measured volume of the sample. Standard working fluid and pending the response value of the killer in the sample solution should be within the linear range of the instrument response. Under the above chromatographic conditions, the retention time of propoxur was about 11.1 Min, according to the peak area external standard method. See Appendix A for standard chromatograms.

7.4 Blank test

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

10.1 Quantitation limits

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

10.2 Recovery rate

The recoveries of the spikes at the level of 0.01 mg/kg, 0.02 mg/kg, 0.05 mg/kg are shown in Appendix B.

GB/T 23200.106-2016

Appendix A

(Informative)

Standard of Gas Chromatography

Figure A.1 Halogen Granite Standard Gas Chromatogram

GB/T 23200.106-2016

Appendix B

(Informative)

Table B.1 Recovery of the three matrix samples

Substrate Name Added Level/(mg/kg) Recovery Range/(%) pork 0.01 80.2 to 107.8 0.02 85.3 ~ 98.7 0.05 88.8 to 96.5 chicken 0.01 83.6 to 102.6 0.02 82.3 ~ 97.0 0.05 87.4 to 97.4 beef 0.01 83.6 to 99.1 0.02 86.6 ~ 99.1 0.05 86.3 ~ 98.8 GB/T 23200.106-2016 Appendix C (Normative appendix) Laboratory repeatability requirements

Table C.1 Laboratory repeatability requirements

Measured component content Mg/kg Precision <=0.001 36 > 0.01 > 1 14 GB/T 23200.106-2016 Appendix D (Normative appendix) Inter-laboratory reproducibility requirements

Table D.1 Inter-laboratory reproducibility requirements

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