HPLC法检测咪鲜胺及其主要代谢物在稻田水土中的残留

Residue Determination of Prochloraz and Its Major Metabolites by HPLC in Paddy Water and Soil

采用HPLC法对稻田水土样品中咪鲜胺及其主要代谢物BTS44595、BTS44596和BTS45186的残留进行了分析与检测。将土壤样品用丙酮提取并浓缩至干后,加入NaCl饱和溶液和pH为9.0的NaHCO3-Na2CO3缓冲液(水样直接加混合溶液),再用石油醚∶丙酮(9∶1,V/V)萃取后检测咪鲜胺母体的残留量,将萃取后的水相调节至pH为2～3,再用石油醚萃取后检测BTS44595、BTS44596和BTS45186的残留量。结果表明,在选定的HPLC检测条件下,咪鲜胺的保留时间为5.384min,最小检出量为3.5×10-10g;BTS44595、BTS44596和BTS45186的保留时间分别为12.365、10.678和8.074min,它们的最小检出量分别为5.0×10-10、3.0×10-10和6.0×10-10g。当添加浓度为0.1、0.5、5.0mg·kg-1时,供试的4种化合物在稻田水和土壤中的添加回收率为76.74%～105.72%,变异系数为2.08%～12.35%。这说明该方法的准确度、重现性和精确度都符合农药残留量分析与检测的要求,适用于对实际样品中咪鲜胺及其主要代谢物残留量的分析与检测。

Prochloraz （1-[N-propyl-N-2-（2,4,6-trichlorophenoxy） ethyl carbamoyl] imidazole ） is a new broad-spectrum imidazole fungicide applied in many crops. There are three major metabolites （BTS44595, BTS44596 and BTS45186） when it is used in the environment. In this study, a high-performance liquid chromatography （HPLC） method for the quantitative determination of the residues of prochloraz and its metabolites in paddy water and soil was developed. Soil sample was extracted with acetone and condensed to dry, and then the extracted soil sample and paddy water sample were adjusted pH approximate to 9.0 with NaHCO3-Na2CO3 buffer solution, respectively. Prochloraz was extracted from the two solutions with petroleum ether：acetone （9：1, V/V） and its metabolites were extracted by petroleum ether from aqueous phases which pH were adjusted to 2-3 using HCl solution. Determinations of analytes were completed using HPLC with UV detection at 210 nm. Under HPLC conditions, prochloraz retain time was 5.384 min and the detection limit was 3.5×10^-10g. BTS44595, BTS44596 and BTS45186 retain time were 12.365, 10.678 and 8.074 min, respectively, and their detection limits were 5.0×10^-10, 3.0×10^-10 and 6.0×10^-10g, respectively. The average recoveries from untreated control samples fortified with these four compounds at rates of 0.1, 0.5 and 5.0 mg·kg^-1 ranged from 76.74 % to 105.72 %, and relative standard deviations were 2.08%-12.35 %. Sensitivity, accuracy and repeatability of the method were fitted for the demand of pesticide residue analysis and detection, and it was easy to perform in practice.