Tsiropoulos NG, Miliadis GE
Department of Theoretical and Applied Sciences, University of Thessaly, Pedion Areos, Volos 38334, Greece, and Benaki Phytopathological Institute, 7 Ekalis Street, Kifissia 14561, Greece.
J Agric Food Chem. 1998 Jan 19;46(1):291-295. doi: 10.1021/jf970712h.
Field studies were undertaken to evaluate the fate of pendimethalin residues in spring and dry onions, after postemergence application of the herbicide in a clay soil onion planting in central Greece, at rates of 1.32 and 2.0 kg of active ingredient (ai)/ha. Residues were determined with capillary GC-ECD after onion extraction with 2-propanol/toluene and extract cleanup in a AgNO(3-)coated alumina column; the recovery of pendimethalin from spiked onions was found to be 82-99% and the limit of determination 0.007 mg/kg. Pendimethalin residues were found to decline rapidly, and it was estimated that 7 days after the treatment only half of the initial concentrations remained for both the low recommended dose (LRD) and the high recommended dose (HRD) experiments. In all cases the residues in dry bulb onion were well below the lowest maximum residue limit (MRL) set by European countries, which is 0.05 mg/kg. Residues in spring onions at harvest time were also below this level when treated at the LRD and were only slightly above in case of the HRD. The pendimethalin concentration in planting soil for the investigated period declined with half-lives of 37 and 39 days for the LRD and the HRD experiments, respectively.
在希腊中部种植于黏土土壤中的洋葱田中，于苗后以1.32和2.0千克活性成分（ai）/公顷的用量施用除草剂二甲戊灵后，开展了田间研究以评估其在春洋葱和干洋葱中的残留情况。用2-丙醇/甲苯提取洋葱后，通过涂覆硝酸银的氧化铝柱对提取物进行净化，然后用毛细管气相色谱-电子捕获检测器测定残留量；发现加标洋葱中二甲戊灵的回收率为82%-99%，测定限为0.007毫克/千克。发现二甲戊灵残留迅速下降，据估计，处理7天后，低推荐剂量（LRD）和高推荐剂量（HRD）试验的初始浓度均仅剩余一半。在所有情况下，干葱中的残留量均远低于欧洲国家设定的最低最大残留限量（MRL），即0.05毫克/千克。以低推荐剂量处理时，收获时春葱中的残留量也低于该水平，而在高推荐剂量处理的情况下仅略高于该水平。在研究期间，低推荐剂量和高推荐剂量试验种植土壤中二甲戊灵的浓度分别以37天和39天的半衰期下降。
