GB 23200.98-2016Food safety national standard -- Determination of Eleven Organophosphorus Pesticide Residues in Royal Jelly by Gas Chromatography (English PDF)

4.1 Reagents

4.1.1 Ethyl acetate (C4H8O2). Chromatographic purity.

4.1.2 acetonitrile (CH3CN). pure chromatography.

4.1.3 Cyclohexane (C6H12). Chromatographic Purification.

4.1.4 Acetone (C3H6O). Chromatographic pure.

4.1.5 Sodium chloride (NaCl)

4.1.6 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 Solution preparation

4.2.1 GPC eluent, ethyl acetate cyclohexane (1 1, volume ratio). take 100 mL of ethyl acetate, add 100 mL of cyclohexane, shake Evenly used. The

4.3 Standards

4.3.1 dichlorvos, methamidophos, methotrexate, phorate, dimethoate, methyl parathion, malathion, parathion, quinophos, triazophos, Flies poison phosphorus standard. purity >= 99%, see Appendix A Table A.1.

4.4 Standard solution preparation

4.4.1 11 kinds of organic phosphorus standard stock solution. Weigh the appropriate standard, respectively, with acetone dissolved to 100 mL, the solution concentration 100 g/mL, 1 °C ~ 4 °C refrigerator. Valid for 3 months.

4.4.2 11 kinds of organic phosphorus mixed standard working solution. before use as necessary with acetone diluted to the appropriate concentration, as a mixed standard working fluid.

1 °C ~ 4 °C refrigerator to save. Valid for 3 months.

4.4.3 Standard working solution concentration. 0.008 g/mL, 0.01 g/mL, 0.05 g/mL, 0.1 g/mL, 0.5 g/mL, Stored in the refrigerator at 4 °C.

4.5 Materials

4.5.1 Gel Purification Product Line (GPC). 400 mm x 15 mm (inner diameter); Filler. Bio-Beads, S-X3, 38 m-75 m Before the need to use the standard solution to do the first leaching curve).

4.5.2 anhydrous sodium sulfate column. 80 mm × 40 mm (diameter) cylindrical funnel, the bottom pad 5 mm absorbent cotton, then install 50 mm anhydrous sodium sulfate.

4.5.3 N-propyl ethylenediamine bonded silica gel (PSA)

5.3 Rotary Evaporator

5.4 vortex mixer.

5.5 Centrifuge >=6 000 r/min.

7.1 Extraction

Weigh 5 g sample (accurate to 0.01 g) in a 50 mL plastic centrifuge tube, add 15 mL of water, mix for 5 min, add B Nitrile to 50 mL on a vortex mixer at 2 000 r/min, mix for 1 min, centrifuge at 6 000 r/min for 5 min, remove the supernatant the solution was placed in another 50 mL plastic centrifuge tube and 4 g of sodium chloride was added to the vortex mixer at 2 000 r/min for 1 min, Centrifuge at 6 000 r/min for 5 min. The upper layer of acetonitrile was passed through an anhydrous sodium sulphate column, collected in a concentrated flask, and then 5 mL of water and 20 ML of acetonitrile to the residue, repeat the above operation, combined acetonitrile extract, 40 °C in the following water bath concentrated to near dry, to be purified.

7.2 Purification

Residue with a solvent volume to 5 mL, mix, take 1.0 mL supernatant GPC column, flow rate 1 mL/min, with solvent elution, before abandoning 15 mL of eluent, collected 15 mL to 30 mL of the eluent, below 40 ° C in the water bath under reduced pressure to near dry, add 8 mL of acetone dissolved, in 40 °C below the water bath with a gentle nitrogen flow to dry, accurately add 1.0 mL of acetone, mix, add 0.05-0.1gPSA mix, over 0.45 m filter for gas chromatography.

7.3 Determination

7.3.1 Chromatographic reference conditions

A) Column. quartz capillary column, DB-1701, 30 m x 0.53 mm (inner diameter) x 1.0 µm (film thickness), or equivalent;

B) Carrier gas. nitrogen (purity greater than 99.999%); constant pressure mode. 89.635 kPa (13 psi); tail gas flow rate. 30 mL/min;

Hydrogen flow rate. 75 mL/min, air flow rate. 90 mL/min;

C) Column temperature. initial temperature 120 ° C for 1 min, rise to 230 ° C at 10 ° C/min, rise to 270 ° C at 20 ° C/min Min;

D) Inlet temperature. 250 ° C;

E) Detector temperature. 250 ° C;

F) Injection mode. pulse splitless injection, pulse pressure 172.375 kPa (25 psi), pulse time 0.75 min;

G) Injection volume. 4 µL;

H) Opening time. 0.75 min;

7.3.2 Chromatographic determination

According to the content of organophosphorus pesticides in the sample, the standard working solution with similar peak area is selected. Standard working solution and sample solution the response value of organophosphorus should be within the linear range of the instrument. Standard working solution and sample volume and other volume interspersed injection determination. In the above chromatographic conditions Dichlorvos, methamidophos, methicillin, chlorophosphate, phorate, dimethoate, methyl parathion, malathion, parathion, quinophos, triazophos, and the reference retention time was about 2.9 min, 3.9 min, 7.3 min, 7.9 min, 10 min, 11.0 min, 11.3 min, 11.9 Min, 12.2 min, 14.5 min, 19.2 min. The chromatogram of the standard is shown in Figure B.1 in Appendix B.

7.4 Blank test

In addition to no sample, according to the above steps.

10.1 Quantitation limits

The limit of 11 kinds of organophosphorus residues was 0.01 mg/kg.

10.2 Recovery rate

The experimental data of the recoveries (within the range of different additive concentrations) are given in Appendix C.

Appendix A

(Normative appendix)

Table A.1 Eleven organophosphate standards information

Standard substance English name CAS NO. Molecular formula Molecular weight Dichlorvos Dichlirvos 52-68-6 C4H7O4CL2P 220.98 Methamidophos 10265-92-6 C2H8NO2PS 141.0 Phenanthroline Ethoprophos 13194-48-4 C8H19O2PS2 242.33 Phorate Phorate 298-02-2 C7H17O2PS3 260.38 Dimethoate 60-51-5 C5H12NO3PS2 229.12 Parathion-methyl 298-00-0 C8H10NO5PS 263.20 Malathion 121-75-5 C10H19O6PS2 330.36 Parathion 56-38-2 C10H14NO5PS 291.26 Quetiapine Quinalphos 13593-03-8 C12H15N2O3PS 298.29 Triazophos 24017-47-8 C12H16N3O3PS 313.31 Flies Phosphorus Coumaphos 56-72-4 C14H16CLO5PS 362.78 Appendix B (Informative) Standard chromatogram 1 - dichlorvos (2.9 min) 2 - methamidophos (3.9 min) 3 - off line phosphorus (7.3 min) 4 - Phorate (7.9 min) 5 - dimethoate (10 min) 6 - methyl parathion (11.0 min) 7 - malathion (11.3 min) 8 - parathion (11.9 min) 9 - quetiophosphate (12.2 min) 10 - triazophos (14.5 min) 11 - fly poison phosphorus (19.2 min)

Figure B.1 Gas chromatograms of 11 organic phosphorus mixed standard solutions (0.05 g/mL)

Appendix C

(Informative)

Sample concentration and recovery of the experimental data

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

Compound Concentration/(mg/kg) Recovery Range /% Precision Range /% Dichlorvos 0.01 82.6 97.2 5.3 0.05 92.4 101.4 3.5 0.1 88.598.6 4.4 Methamidophos 0.01 70.6 80.7 6.2 0.05 72.8 97.6 10.6 0.1 75.1 99.7 11.7 Off line phosphorus 0.01 106.5 110.0 1.5 0.05 93.6 100.0 2.5 0.1 90.9 99.9 4.0 Phorate 0.01 93.8 99.3 2.4 0.05 85.8 99.8 5.6 0.1 81.8 97.0 7.0 Dimethoate 0.01 97.5 110.0 4.1 0.05 71.2 78.6 3.4 0.1 80.6 89.7 3.8 Methyl parathion 0.01 96.0 109.5 4.7 0.05 95.0 105.5 4.1 0.1 91.9 106.6 6.5 Malathion 0.01 96.1 110.0 4.9 0.05 82.4 91.6 4.0 0.1 80.4 97.1 7.4 Parathion 0.01 97.0 109.1 3.9 0.05 84.8 102.2 6.9 0.1 80.7 90.8 5.0 Quetiapine 0.01 95.3 106.1 3.6 0.05 73.2 95.8 10.2 0.1 70.8 78.6 4.2 Triazophos 0.01 78.2 98.5 7.9 0.05 89.0 106.2 5.9 0.1 82.6 100.2 8.8 Flies phosphorus 0.01 100.1 109.8 3.3 0.05 86.6 106.2 7.0 0.1 88.0 110.0 10.0 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