PAR分光光度法测定汽油中的痕量铅

PAR Spectrophotometric Determination of Trace Pb in Gasoline

研究了快速测定汽油中痕量铅的方法。测定经盐酸处理过的汽油与 PAR反应生成的络合物。该显色体系最大的优点是可在水相中直接用光度法测定样品中铅的含量。该配合物最大的吸收波长为 5 2 0 nm,ε52 0 =2 .2× 10 4 L· (m ol· cm ) - 1 ,Pb浓度在 0～ 2 5 .2μg· m L- 1 范围内线性关系良好 ,回归方程 A=0 .12 711C- 0 .0 6 2 93,相关系数为 0 .9992 ,检出限为 0 .4 1μg· m L- 1 。本方法显色迅速 ,稳定 ,操作简便 ,避免了使用氰化钾剧毒试剂 ,以及萃取等烦琐操作 ,可在 35 min内完成

A new method for rapid determination of trace Ph in ga so line was investigated. In ammonium chloride buffer solution of pH 6.5, Pb in gas oline was reacted with 4-(2-pyridylazo) resorcinol (PAR) to form a complex. Th e maximum absorption wavelength was at 520nm. The molar absorptive coefficient w as 2.2×10~4 L/(mol·cm). Beer's law was obeyed in the concentration range of 0 ~25.2 μg/mL Pb, and the correlation coefficient was 0.9992.