【摘要】 <正> 一、前言 某生产乐果与敌敌畏的农药厂多年来对车间排放废水采取了碱化与生化曝气相结合的方法进行了治理,但其周围地下水仍有明显臭味。为了确定地下水是否被此农药厂污染,开展了本项研究工作。 关于有机磷农药的分析,前人已经进行过大量工作,但几乎都是针对农药在农作物上残留量的测定。对水中有机磷农药含量的气相色谱分析则报导甚少。上述这些研究无例外地更多还原

【Abstract】 The well water near an organic phosphorus pesticide plant manufacturing Rogor (Dimethoate) and DDVP,has long been suspected to be polluted by the plant effluent. For characterization of the main pollutants in the well water, a dual column GC method of identification was applied, using two GC columns with different polarity. One glass column, with dimension of 0.8m× 2.5mm, was packed with 3% DEGA on Celite 545 (AW DMCS, 60-80 mesh) and the other, with dimension of 1m ×3mm, was packed with 5% DC-710 on the same support. A FPD with a 525 nm P-filter and a 394 nm S-filter was employed. Water sample, taken from different polluted well around the plant at all seasons during a two years’ period, were extracted with 1/100 its volume of benzene, and the benzene extracts then concentrated in a Kuderna-Danish evaporator. After enrichment of the samples to a factor of 2 x 10% the benz-ene extracts were injected into the gas chromatograph. It was constantly found that 7-8 peaks appeared in the chromatograms, three of them being predominant. By com-parison of the retention time of the three main unknowns with those of the known standards, two peaks were successfully identified to be O,O, S-trimethyldithiophos-phate (2053-29-9) and O,O, O-trimethylthiophosphate (152-18-1). Both were the first stage by-products in the synthesis of Dimethoate, as P2S5 reacted with methanol to yield O, O-dimethyldithiophosphoric acid. The third main pollutant failed to be id-entified, but it was also a P-and S-containing organic compound, emerging from the Dimethoate workshop in the Pesticide Plant. The pollutants in the well water were at a ppb level, but the contamination already caused unpleasant taste and odour.更多还原