液膜分离与火焰原子吸收法结合测定镉、铜

Determination of Cadmium and Copper by the Co-operation Method of Flame Atomic Absorption Pectrometry and Liquid Membrane Separation

液膜分离是一种高效低成本的金属离子预富集手段,本文采用组成为载体P-204(8%),表面活性剂Span-80(3%),膜稳定剂液体石蜡(0.5%),膜溶剂煤油(88.5%),内相HCl的浓度2.0mol/L的液膜萃取体系,考察了萃取时间、外水相酸度、转速、乳水比的分离条件对镉萃取率的影响。实验优化后的萃取条件为萃取时间10min、外水相pH=4.50、乳水比1:4、搅拌速度200r/min;将液膜分离与火焰原子吸收相结合检测镉、铜离子,结果表明,此法灵敏度高、检测限低、检测范围宽。

The liquid membrane separation technique was regarded as an advanced and efficient means for the simultaneous extraction and pre-concentration of trace metal elements from aqueous solution. In this thesis,a water-in-oil type emulsion system consisting of 8% P-204,3% Span-80,0.5% paraffin and 88.5% kerosene vigorously mixed with 2.0 mol/L HC1 as internal aqueous phase has been studied. The important parameters such as extracting time, stirring speed, feed phase pH, and the treatment ratio were considered. The results showed that the higher extraction effect could be obtained by using feed phase pH at 4.50, 1：4 of treatment ratio, 200 r/min stilting speed and extracting for 10 min. The research result proved that this method is of higher sensitivity, lower detection limit and wider working range.