Eskilsson C S, Mathiasson L
Department of Analytical Chemistry, Lund University, P.O. Box 124, S-221 00 Lund, Sweden.
J Agric Food Chem. 2000 Nov;48(11):5159-64. doi: 10.1021/jf000275y.
Large amounts of contaminated process dust remain from the procedure of pesticide treatments applied to seed pellets. A pilot study in analytical-scale supercritical fluid extraction (SFE) was performed to determine the possibility of using supercritical carbon dioxide for the extraction of the nonpolar insecticide carbosulfan and the more polar insecticide imidacloprid present in contaminated dust waste, at concentrations of up to 20% (w/w). The effects of various experimental conditions, such as temperature, flow rate, and addition of modifier, on the recovery of the analytes were evaluated by extracting the pesticides both from spiked support material and from real dust samples. It was found that carbosulfan could easily be extracted from the dust waste within 30 min at 138 bar and 40 degrees C with a recovery of 98.9% (RSD = 2.3%, n = 10), compared to values obtained with a validated liquid extraction method. A sufficient removal of the more polar substance imidacloprid required the addition of a modifier, and the results showed a strong dependence of the extraction efficiency on the choice of modifier. Extractions at 276 bar and 80 degrees C with a solvent consisting of supercritical carbon dioxide modified with methanol (5%) gave a recovery of 97.0% (RSD = 3.6%, n = 10) using a 40 min extraction time. The results indicate that it seems to be possible to use process-scale SFE for the decontamination of pesticides from dust waste. The conditions outlined also permit analytical determinations of the two insecticides based on a combination of SFE and liquid chromatography.
在种子颗粒农药处理过程中会残留大量受污染的工艺粉尘。进行了一项分析规模超临界流体萃取（SFE）的初步研究，以确定使用超临界二氧化碳从受污染粉尘废物中萃取非极性杀虫剂丁硫克百威和极性更强的杀虫剂吡虫啉的可能性，这些粉尘废物中杀虫剂的浓度高达20%（w/w）。通过从加标载体材料和实际粉尘样品中萃取农药，评估了温度、流速和改性剂添加等各种实验条件对分析物回收率的影响。结果发现，在138巴和40℃下，30分钟内即可轻松从粉尘废物中萃取出丁硫克百威，回收率为98.9%（RSD = 2.3%，n = 10），与经过验证的液体萃取方法得到的值相比。对于极性更强的物质吡虫啉，要实现充分去除需要添加改性剂，结果表明萃取效率强烈依赖于改性剂的选择。在276巴和80℃下，使用由5%甲醇改性的超临界二氧化碳组成的溶剂进行萃取，萃取时间为40分钟，回收率为97.0%（RSD = 3.6%，n = 10）。结果表明，使用工艺规模的SFE从粉尘废物中去除农药似乎是可行的。所述条件还允许基于SFE和液相色谱联用对这两种杀虫剂进行分析测定。
