高效液相色谱法同时测定棉花及土壤中丁草胺和异噁草酮的残留

建立了同时测定丁草胺和异噁草酮棉花及土壤中的残留的高效液相色谱分析方法。样品经乙腈提取,中性氧化铝柱净化,紫外检测器检测。丁草胺和异噁草酮的最小检出量分别为5.0×10-10和1.0×10-9 g,样品的最低检出浓度均为005 mg·kg-1。棉叶、棉籽和土壤中添加浓度为0.05～1.0 mg·kg-1 时,丁草胺的平均回收率为88.78%～99.52%,相对标准偏差(RSD)为0.49%～2.09%；异噁草酮的平均回收率为85.57%～101.82%,相对标准偏差(RSD)为0.97%～2.44%。该方法的准确度、精密度及灵敏度均达到农药残留分析的要求。将该方法应用于丁草胺和异噁草酮在棉花及土壤中的残留试验中,测得丁草胺在棉叶和土壤中的残留消解半衰期分别为2.14和2.53 d, 异噁草酮在棉叶和土壤中的残留消解半衰期分别为2.80和2.82 d,收获时土壤和棉籽中丁草胺和异噁草酮的最终残留量均小于0.05 mg·kg-1。

Simultaneous determination of butachlor and clomazone in cotton and soil by high performance liquid chromatography

An analytical method was established for simultaneous determining butachlor and clomazone residues in cotton and soil. Samples were extracted with acetonitrile, cleaned up by passing through an aluminum oxide (neutral) column, determined by reversed phase HPLC with an ultraviolet detector. When the sample was spiked at 0.05-1.0 mg·kg-1, the average recovery varied from 88.78% to 99.52% (RSD 0.49%-2.09%) for butachlor and 85.57% to 101.2% (RSD 0.7%-2.4%) for clomazone. The lowest detection limit for butachlor and clomazone was 5.×10-10 and 1.×10-9 g, respectively. The lowest detectable concentration was 0.5 mg·kg-1 in cotton seeds and soil. The proposed method met the demands of pesticide residue analysis. The degraded dynamic in cotton leaves and soil indicated that the half lives of butachlor were 2.4 and 2.3 days, and the half lives of clomazone were 2.4 and 2.3 days. The final residues of butachlor and clomazone in soil and cotton seeds were less than 0.5 mg·kg-1．