School of Applied Science, University of Science and Technology, 100083 Beijing, China.
Bull Environ Contam Toxicol. 2011 Jan;86(1):95-100. doi: 10.1007/s00128-010-0130-x. Epub 2010 Nov 17.
A sensitive and simple method for simultaneous analysis of acetochlor and propisochlor in corn and soil has been developed. Two herbicides were extracted from soil and corn matrices with methanol/water and acetone, respectively, followed by solid phase extraction (SPE) to remove co extractives, prior to analysis by gas chromatography with electron capture detection (GC-ECD). Primary secondary amine (PSA) SPE cartridges (500 mg, 3 mL) were used for sample preparation. The analytes from corn and soil matrices were eluted with 5 mL petroleum ether-acetic ether (95/5, v/v) and 3 mL petroleum ether-acetic ether (95/5, v/v), respectively. The recoveries of two pesticides ranged from 73.8% to 115.5% with relative standard deviations (RSD) less than 11.1% and sensitivity of 0.01 mg/kg, in agreement with directives for method validation in residue analysis. The method was successfully applied to determine the fate of acetochlor and propisochlor in real corn and soil samples. For acetochlor and propisochlor, the half-life times (t1/2) in soil was 5.541 and 6.074 days, respectively. No acetochlor and propisochlor residues (<0.01 mg/kg) were detected in corn at harvest time withholding period of 2.5 months after treatments of the pesticides. Direct confirmation of the analytes in samples was achieved by gas chromatography-mass spectrometry (GC-MS).
已开发出一种灵敏、简单的方法，可同时分析玉米和土壤中的乙草胺和异丙甲草胺。两种除草剂分别用甲醇/水和丙酮从土壤和玉米基质中提取，然后用固相萃取（SPE）去除共提取物，再用电子捕获检测气相色谱（GC-ECD）进行分析。采用初级二级胺（PSA）SPE 小柱（500mg，3mL）进行样品制备。玉米和土壤基质中的分析物分别用 5mL 石油醚-乙酸乙酯（95/5，v/v）和 3mL 石油醚-乙酸乙酯（95/5，v/v）洗脱。两种农药的回收率在 73.8%至 115.5%之间，相对标准偏差（RSD）小于 11.1%，灵敏度为 0.01mg/kg，符合残留分析方法验证的指令。该方法成功应用于测定真实玉米和土壤样品中乙草胺和异丙甲草胺的命运。对于乙草胺和异丙甲草胺，其在土壤中的半衰期（t1/2）分别为 5.541 和 6.074 天。在施药后 2.5 个月的收获期保留期内，玉米中未检测到乙草胺和异丙甲草胺残留（<0.01mg/kg）。通过气相色谱-质谱联用（GC-MS）直接确证了样品中的分析物。
