Determination on Pyrethroids Residues in Tea with Gas Chromatography

The purpose aimed to study the optimum experiment of determining and analyfing pyrethroid pesticides in tea.The paper discussed the extracted and purified method from tea samples,and the determination condition of gas chromatography by external standard method.The results were as follows:the opitimal chromatography condition was gained,the starting temperature was 180 ℃,the final temperature was 270 ℃ and kept 15 minutes;The extracted and purified condition was took petroleum ether-acetone(V/V,3:1)as extracting solution,cleaned up with the Florisil column,eluted with petroleum ether-ethylacetate(V/V,9:1).The test of recovery and precision showed a good linearity on linear equation in the concentration range 0.008~0.800 mg/L,r(correlation coefficient)≥0.997 3,the recovery were in the ranges of 80.7%~105.8%,the relative standard deviation were in the ranges of 2.5%~8.9%,the detection limits were in the ranges of 0.000 3~0.004 2 mg/kg.