Study On The Determination Of Pesticide Residues In The Environmental Water Samples And Agricultural Products

Environmental issues are very concerned problems in the world, and the pollution of pesticide residues is a serious threat to human food safety.Governments established more and more rigorous evaluation standard on pesticide residues. Therefore, to guarantee food security the rapid detection methods of pesticide residue are very significant and important.In this study, single drop liquid-phase microextraction(SD-LPME) and dynamic liquid-phase microextraction (D-LPME) combined with high performance liquid chromatography(HPLC) have been developed for the determination of Diafenthiuron and Pendimethalin pesticide residues in water and fruit juice. This thesis mainly included four aspects:1. A novel method for the determination of diafenthiuron in water by pretreatment technology of sample, which is based on ionic liquid single drop liquid-phase microextraction(SD-LPME), and high performance liquid chromatography(HPLC) has been developed. Under the optimum conditions, the enrichment factors of the diafenthiuron was about 91,the detection limits was 0.03mg/L, the relative standard deviations (RSD) was 2.1% (n=6), the recoveries of added diafenthiuron fe1l in the range from 88.0%～106%.2. A novel method was developed for the determination of diafenthiuron in water and fruit juice by dynamic liquid-phase microextraction (D-LPME) with high performance liquid chromatography (HPLC). Under the optimum conditions, the enrichment factors of the diafenthiuron was about 117,the detection limits was 0.088 mg/L, the relative standard deviations (RSD) was 2.93%, the recoveries of added diafenthiuron fe1l in the range from 81.0%～110% .3. A methods for simultaneous determination of diafenthiuron and pendimethalin in water and fruit juice by dynamic liquid-phase microextraction (D-LPME) coupled with high performance liquid chromatography(HPLC) have been developed. The variable experimental conditions for dynamic liquid-phase microextraction process were optimized. Under the optimum conditions, the enrichment factors of the diafenthiuron was about 94,the detection limits was0.039mg/L, the relative standard deviations (RSD) was 1.29%, the recoveries of added diafenthiuron fe1l in the range from 89.0%～113%; the enrichment factors of the pendimethalin was about 113,the detection limits was0.043mg/L, the relative standard deviations (RSD) was 1.43%, the recoveries of added diafenthiuron fe1l in the range from 83.0%～109%.The results are satisfactory.