氯氟吡氧乙酸在小麦及土壤中残留的分析方法

采用氢氧化钠-甲醇溶液提取,二氯甲烷萃取,定量甲醇、浓H2SO4条件下酯化,气相色谱法测定小麦及土壤中的氯氟吡氧乙酸。氯氟吡氧乙酸质量浓度在0.01~1.0 mg.L-1之间线性关系良好。在添加浓度0.01~0.8 mg.kg-1下,植株、土壤和籽粒中氯氟吡氧乙酸的平均回收率分别为72.3%~86.7%、83.6%~95.8%和77.7%~87.3%,变异系数分别为3.02%~8.59%、2.87%~8.46%和2.75%~7.61%。氯氟吡氧乙酸的最小检测量为1.0×10-11g,在植株、土壤和籽粒中最低检出浓度均为0.01 mg.kg-1。该方法的准确性、精确性和灵敏度均满足农药残留分析的要求。

Analytical method for fluroxypyr residues in wheat and soil

Gas chromatography was used to analyse fluroxypyr residues in wheat and soil.Residues of fluroxypyr were extracted from wheat and soil with a solution of sodium hydroxide-methanol,cleaned up by liquid-liquid partitioning, esterified with quantitative methanol and 98% H_2SO_4,and detected by gas chromatography with ECD.The calibration curve had good linearity in the range of 0.01～1.0 mg·L~(-1).The average recoveries of wheat plant,soil and wheat seed at the spiked amounts of 0.01～0.8 mg·L~(-1) were 72.3%～86.7%,83.6%～95.8% and 77.7%～87.3%,and the coefficients of variation were 3.02%～8.59%,2.87%～8.46% and 2.75%～7.61%, respectively.The minimum detectable amount of fluroxypyr was 1.0×10~(－11) g,the minimum detectable concentration of fluroxypyr in the samples of wheat plant, wheat seed and soil was 0.01 mg·kg~(-1).The results showed that the method meet with demands of residue analysis of pesticide.