Study On The Determination Methods Of Organophosphorus Pesticides Multiresidues In Tobacco

Pesticide residue is not only an important factor in quality evaluation of tobacco, but also a main measurement target in global trading. And because of its merits such as higher activity, organophosphorus pesticides are widely used in Chinese agricultural production. Therefore this research is keen on the determination methods of organophosphorus pesticides multi-residues in tobacco. The objective is to extend the coverage of current determination method system of our country's pesticides residues in tobacco. The essay describes the determination methods of pesticide residues in detail. And two different determination methods were developed for the analysis of organophosphorus pesticides multi-residues in tobacco. Details are as follows:1. The extract of pesticide residues from tobacco with acetone, was cleaned by liquid-liquid partition with ethyl acetate and cyclohexane, and following purified by gel permeation chromatography (GPC). The organophosphorus pesticide residues were determined by gas chromatography with FPD. The method was developed for the analysis of ten organophosphorus pesticide residues in tobacco. The method featured with recoveries 72.8%~108.1% and RSD 1.09%~5.81%.This method is accurate and credible.2. Extract multi-residues of organophosphorus pesticides in tobacco with dichloromethane. Filter the extract and concentrate to nearly dry. Then dissolve residues with ethyl acetate and cyclohexane solution. Then the organophosphorus pesticide residues were determined by gas chromatography with FPD. The method was developed for the analysis of fourteen organophosphorus pesticide residues in tobacco. The method featured with recoveries 83.1% —110.5% and RSD 3.83%~ 12.63%. It indicates that the recovery of this method is higher, and repeatability is good. It meets the requirements of pesticides determination. This method is accurate and credible.3. The effect of different matrixes to the response of pesticide residues has been studied. It indicates that the same concentration standard solution in different matrix has obvious different response of gas chromatography. So the effect of matrix should be considered when...