Rai M K, Das J V, Gupta V K
Department of Chemistry, Government College of Khairagarh, Distt. Rajnandgaon, M.P. 492881, India.
Talanta. 1997 Dec 19;45(2):343-8. doi: 10.1016/s0039-9140(97)00136-7.
A sensitive spectrophotometric method for the determination of a widely used herbicide, paraquat using a versatile reducing agent sodium borohydride is described. Paraquat is reduced with sodium borohydride in an alkaline medium to give a blue radical ion with an absorbance maxima at 600 nm. Beer's law is obeyed in the range of 0.05-0.5 mug ml(-1) of paraquat. The molar absorptivity and Sandell's sensitivity are found to be 2.9 x 10(5) l mol(-1) cm(-1) and 0.0006 mug cm(-2) respectively. The important analytical parameters and the optimum reaction conditions were evaluated. The method is free from the interference of other commonly used pesticides and metal ions. The method was applied successfully to the determination of paraquat in human samples, such as blood, urine and mother's milk compared to food and environmental samples.
描述了一种灵敏的分光光度法，该方法使用通用还原剂硼氢化钠来测定一种广泛使用的除草剂百草枯。在碱性介质中，百草枯与硼氢化钠反应被还原，生成一种在600nm处有最大吸收的蓝色自由基离子。百草枯浓度在0.05 - 0.5μg ml⁻¹范围内符合比尔定律。摩尔吸光系数和桑德尔灵敏度分别为2.9×10⁵ l mol⁻¹ cm⁻¹和0.0006μg cm⁻²。评估了重要的分析参数和最佳反应条件。该方法不受其他常用农药和金属离子的干扰。与食品和环境样品相比，该方法已成功应用于人体样品（如血液、尿液和母乳）中百草枯的测定。
