Huang L Q, Pignatello J J
Connecticut Agricultural Experiment Station, New Haven 06504.
J Assoc Off Anal Chem. 1990 May-Jun;73(3):443-6.
A method was developed for extraction of weathered residues of atrazine and metolachlor from field soils; soils had last been treated with commercial formulations of the herbicides 8-15 months prior to sample collection. Maximum yields were obtained by batch extraction at 75 degrees C for 2-16 h with methanol-water (80 + 20) in a sealed vial. Hydrolysis or other decomposition reactions were minor or negligible, depending on the extraction time. This method is an improvement over published methods that are validated by spike recoveries; the proposed method gives 1.7-1.8 times higher yields compared to shaking for 2 h at room temperature, and 1.3-1.8 times higher yields compared to Soxhiet extraction. The reproducibility of the method was better than 12%. The results underscore the impact of nonequilibrium sorption of organic compounds on analytical methodology and emphasize the need to validate extraction methods with field samples.
开发了一种从田间土壤中提取莠去津和异丙甲草胺风化残留物的方法；在采集样品前8 - 15个月，土壤最后一次用除草剂商业制剂处理。通过在密封小瓶中用甲醇 - 水（80 + 20）在75℃下分批萃取2 - 16小时可获得最大产量。根据萃取时间，水解或其他分解反应较小或可忽略不计。该方法是对通过加标回收率验证的已发表方法的改进；与在室温下振荡2小时相比，该方法的产量高出1.7 - 1.8倍，与索氏提取相比，产量高出1.3 - 1.8倍。该方法的重现性优于12%。结果强调了有机化合物非平衡吸附对分析方法的影响，并强调了用田间样品验证提取方法的必要性。
