摘要
采用气相色谱法对肯尼亚沿Nzoia河9个地点的水样和沉积物样中草不绿(也称杂草锁)(α’-氯-N-(2,6-二乙基苯基)-N-(甲氧基甲基)乙酰胺)、甲氧毒草安(α-氯6’-乙基-N-(2甲氧基-1-甲基乙基)乙酰邻甲苯胺)及它们各自环境稳定的苯胺类降解物2,6-二乙基苯胺、2-乙基-6-甲基苯胺进行分析。降解物在90%以上的沉积物样和水样中检出,而母体化合物只在不到14%的水样中检出。沉积物中的杀虫剂和它们的降解物比在水中浓度高很多(1.4～10 800倍),显示出化合物在沉积物中的积累。在研究时间内沉积物中降解物的普遍存在意味着这些化合物的持续性。可以假定在热带气候为主的条件下,促使杀虫剂快速分解为环境稳定的降解物,从而在研究区域内使后者成为比其母体更重要的污染物。
Alachlor, metolachlor and their respective environmentally stable aniline degradation products, 2,6-diethylaniline and 2-ethyl-6-methylaniline were analyzed in water and sediment samples from 9 sites along River Nzoia, Kenya using gas chromatography. The degradation products were detected in > 90% of the sediment and water samples, while the parent compounds occurred in < 14% of the water samples. Much higher concentrations of the pesticides and their degradation products occurred in the sediment than in the water (1.4 up to 10 800-fold), indicating an accumulation of the compounds in the sediment. The constant occurrence of the degradation products in the sediment during the study period infers a persistence of these compounds. It is hypothesized that the prevailing tropical climatic conditions favor a quick breakdown of the pesticides to their environmentally stable degradation products, thereby making the latter more important pollutants than their parent products in the study area.
