论文部分内容阅读
一般有机磷杀虫剂的测定,可经过硝化后用钼蓝法进行比色,或用胆硷酯酶活性被抑制的程度进行测定。但是,敌敌畏(DDVP)在空气中很易分解,分解后的磷酸二甲酯也可与钼酸铵生成蓝色反应,故不宜用此法进行测定。而胆硷酯酶法需要的器材比较难得,操作也较麻烦。目前测定敌敌畏比较具有特异性的方法有:(1)间苯二酚法、(2)2,4-二硝基苯肼法、(3)氢氧化钾的醇溶液法、(4)极谱法、(5)联苯胺-过硼酸钠法。第(1)(2)法系根据敌敌畏的分解产物与试剂呈色反应而进行测定,因此失去生物效用的分解产物也具有阳性反应。为了要测出未分解的敌敌畏,在第(2)法中提出两步操作——先测出空气中总的二氯乙醛,再减去游离的二氯乙醛;第(3)法需要用丙酮作为介质,若用丙酮作吸收液,自空气中取样
General organophosphorus insecticide determination, after nitrification by molybdenum blue colorimetric, or cholinesterase activity is inhibited to determine the degree. However, DDVP is easily decomposed in the air, and the decomposed dimethyl phosphate can also generate a blue reaction with ammonium molybdate. Therefore, it is not suitable for the determination of this method. The cholinesterase method requires more rare equipment, the operation is more troublesome. Currently measured dichlorvos more specific methods are: (1) resorcinol method, (2) 2,4 - dinitrophenylhydrazine method, (3) potassium hydroxide alcohol solution, (4) polarographic Method, (5) benzidine - sodium perborate method. Law (1) (2) is based on the color reaction of the products of decomposition of dichlorvos with reagents, and therefore also has a positive reaction with decomposition products that lose their biological usefulness. In order to determine the undecomposed dichlorvos, a two-step procedure is proposed in item (2) - first to determine the total amount of dichloroacetaldehyde in the air, and then subtract the free dichloroacetaldehyde; and (3) Acetone as a medium, if acetone as absorbent, sampling from the air