Method for detecting 18 kinds of organic chloride pesticide residues in Chinese medicinal material

[0012] The following embodiments help those skilled in the art to better understand the present invention, but do not limit the present invention in any way. Example 1: Multi-residue analysis of 18 organochlorine pesticides in chrysanthemum

[0013] The chrysanthemum samples were dried in the shade, crushed, and passed through a 60-mesh sieve. Accurately weigh 2.0g sample, add 2.0g anhydrous Na 2 SO 4 , Grind thoroughly, and transfer to a 100mL Erlenmeyer flask with stopper. Add 30 mL of acetone: petroleum ether (1:1) and ultrasonically extract for 15 min, let it stand, and filter the supernatant into a 100 mL pear-shaped bottle. The extraction was repeated twice with 20 mL of acetone: petroleum ether (1:1), and the operation was the same as above. The collected filtrate was concentrated in a 40°C water bath to nearly dryness. Quantitatively transfer the concentrated residue with petroleum ether to a 10 mL graduated test tube with a stopper to make the volume to 5 mL, carefully add 1 mL of concentrated sulfuric acid containing 10% water, shake for 1 min, centrifuge at 3000 rpm for 10 minutes, and take the supernatant Measured by liquid gas chromatograph.

[0014] Results: The average yields of the three levels of this method were 93.2%, 93.4%, 90.7%, and the RSD values ​​were 11.0%, 7.5%, and 6.9%. Conclusion: The method is quick, simple, low cost, and accurate.

[0015] Example 2 Multi-residue analysis of 18 organochlorine pesticides in ginkgo leaves

[0016] The ginkgo biloba samples were dried in the shade, crushed, and sieved. Accurately weigh 2.0g sample, add 2.0g anhydrous Na 2 SO 4 , Grind thoroughly, and transfer to a 100mL Erlenmeyer flask with stopper. Add 30 mL of acetone: petroleum ether (1:1) to ultrasonically extract for 15 min, let it stand, and filter the supernatant into a 100 mL pear-shaped bottle. The extraction was repeated twice with 20 mL of acetone: petroleum ether (1:1), and the operation was the same as above. All the collected filtrate was concentrated in a water bath at 40°C to nearly dryness. Quantitatively transfer the concentrated residue with petroleum ether to a 10 mL graduated test tube with a stopper to make the volume to 5 mL, carefully add 1 mL of concentrated sulfuric acid containing 10% water, shake for 1 min, separate the center at 3000 rpm for 10 min, and take the supernatant into Gas chromatography determination.

[0017] Results: The recoveries of the three levels of this method ranged from 71.6% to 130.3%, and the RSD was from 2.2% to 15.8%. Conclusion: The method is simple and quick, and the result is reliable.