【摘要】 植物水解酶催化α-乙酸萘酯水解生成α-萘酚,α-萘酚与三氯化铁溶液发生显色反应生成紫色络合物,该络合物最大吸光度位于516nm波长处。而此显色反应因有机膦农药的存在而受到抑制,有机膦农药的质量浓度与吸光度的下降程度(ΔA)呈线性关系,据此建立了植物水解酶催化-分光光度法快速测定痕量有机膦农药的方法。对反应的温度、反应时间和缓冲溶液的pH值等因素进行了试验并予以优化。敌敌畏、敌百虫、甲胺膦、乐果和水胺硫膦等有机膦农药的检出限(3S/N)在0.001~0.25 mg.L-1范围内,相对标准偏差(n=6)均小于5.5%。所提出的方法应用于蔬菜中有机膦农药的测定,加标回收率在87.0%~93.0%之间。更多还原

【Abstract】 The hydrolysis of α-naphthyl acetate was catalyzed with plant-esterase,and α-naphthol was obtained.A purple complex was formed by the color reaction of α-naphthol with FeCl3,with its absorption maximum at the wavelength of 516 nm.The color reaction was inhibitated by the presence of organo-phosphorus pesticides,and linear relationship between mass concentration of organo-phosphorus pesticides and decrease of absorbance(ΔA) was obtained.Based on these facts,a method for rapid determination of organo-phosphorus pesticides was proposed.Experimental conditions,including reaction temperature,reaction time,pH of buffer solution and interference of co-existing ions,were studied and optimized.Detection limits(3S/N) of dichlorophos,dipterex,methamidophos,dimethoate and isocarbophos were in the range of 0.001-0.25 mg·L-1,and RSD′s(n=6) found for these pesticides were less than 5.5%.The method was used in the analysis of vegetables,values of recovery found by standard addition method were in the range of 87.0%-93.0%.更多还原