The Analytical Study Of Pyrethroids And Organophosphorus Pesticide Residues In Tobacco

The issue of pesticide residues in tobacco has been noticed widely, which makes smoking to be a security risk, and also affects the smooth of tobacco trade to a certain degree, thus we need to increase financial and technical input, strengthen research and development, improve the level of detection on pesticide residues urgently. This paper is based on the sheet of pesticide residue limits in tobacco which was published by CORESTA. Considering our laboratory having done some research work, The content is to have a further study on analytical method of flumetralin, pyrethroids and organophosphorus pesticide residues in tobacco.The dissertation contains four parts:In chaper one, a general overview of the treatment and detection methods about pesticide residues was given.In chaper two, a determination method of pyrethroids and flumetralin pesticide residues in tobacco had been developed. Samples were extracted by ultrasonic and cleaned up with Florisil solid phase extract column. Eight pyrethroids and flumetralin quantification were achieved by gas chromatography with electron capture detection (GC-ECD). Compared with the available standard method of GB/T 13595-2004, the pretreatment of the new method was easy, rapid, cheap and less solvent consumption. The recoveries of eight pyrethroids and flumetralin pesticides ranged from 86.7% to 110.9% at the spiking levels of 0.1,0.5 and 1μg/g, with relative standard deviation from 0.20% to 4.1%. This method could meet present requirements on multiresidue determination in tobacco well.In chaper three, a determination method of organophosphorous pesticide residues in tobacco had been developed. Samples were extracted by acetonitrile, cleaned up with PSA and detected by Gas chromatogaphy-mass spectrometry. The method was easy, rapid, cheap and with high accuracy. The recoveries of twenty organophosphorous pesticides ranged from 70.0% to 118.4% at the spiking levels of 0.1,0.5 and 1μg/g, with relative standard deviation from 0.50% to 12%. This method could meet present requirements on multiresidue determination in tobacco well. In chaper four, analytical conditions of organophosphorous pesticide residues in tobacco were studied by ion-trap GC/MS/MS. Organophosphorous pesticide residues were separately detected by full scan mode, selected ion mode and MS/MS mode. The results showed twenty peaks of organophosphorous pesticides could not be separated completely in full scan mode, however, MS/MS and SIM mode had its own respective advantage on qualification and quantification, thus samples could be analysed by both at the same time in order to achieve the best analytical conditions.