【摘要】 <正> 我们在上文已报导,生产乐果和敌敌畏的某农药厂附近的自来水井中,在我们所用的二根色谱柱上,都各自出现了三个主要的有机磷色谱峰。而这三个主要色谱峰没有一个是农药敌敌畏或乐果。经过鉴定,其中一个色谱峰是乐果生产的付产品,所谓中性油的主要组份O,O,S-三甲基二硫代磷酸酯[2953—29—9]。另一个色谱峰也是中性油的一个组份O,O,O-三甲基—硫代磷酸酯[152—18—1]。还有一个色谱峰则至今仍是未知。对此二已知化合物的气相色谱测定,我们还未发现文献上有过报导。因此,我们拟定了下列的测定方法,并进行了萃取率和浓缩回收率的测定。更多还原

【Abstract】 Based on previous studies, a GC method for the determination of the main pol-lutants, i. e. O,O, S-trimethyldithiophosphate and O,O, O-trimethylthiophosphate, has been worked out with preliminary solvent extraction of the well water sample with either benzene or chloroform, followed by the concentration of the extract in a Kuderna-Danish evaporator under partial vacuum. The GC determination of the two pollutants was carried out on either one of the following two columns. 3% DEGA/ Shanghai Chemical Co. 101 AW DMCS, 60-80 mesh, 1m×2.5 mm and 5% PEG 20M/Celite 545 AW DMCS, 60-80 mesh, 1m×3 mm. Flame photometric detector with a 525 nm P-filter was used. The recovery rate of solvent extraction with benzene or chloroform and the concentration recovery rate in Kuderna-Danish evaporator were also determined at several fortification levels. If a well water sample of 3 L was taken and extracted with 30 ml benzene, and one half of it was reduced to a volume of 0.5 ml, then the lower limit of determination reached to 0.07 ppb when 1/μl of the concentrated extract was injected. The total recoveries of O,O, S-trimethyldi-thiophosphate and O, O, O-trimethylthiophosphate were 97% and 78% respectively. The method recommended was quite sensitive and easily reproducible.更多还原