Cold induced aggregation microextraction with an ionic liquid for trace determination of cadmium and lead in water samples

Abstract

Cold induced aggregation microextraction (CIAME) with an ionic liquid has been used as a rapid and simple method for determination of trace amounts of cadmium and lead by sequential analysis with flame atomic absorption spectrometry. In this study, cadmium and lead have been complexed with O, O-diethyldithiophosphate as chelating agent in a solution containing Triton X-114 and sodium hexafluorophosphate, and then extracted into an ionic liquid. The effect of various parameters on extraction efficiency such as amounts of [C₆MIM][PF₆] and NaPF₆, <i style="">p</i>H of solution, extraction time, temperature and complexing agent concentration have been optimized. Under the optimized conditions, the detection limits are 0.12 µg L^-1 and 1.61µg L^-1, relative standard deviation 2.4 % and 2.7 % and enrichment factor 70 and 67 for cadmium and lead, respectively. The proposed method has been successfully applied for analysis of cadmium and lead in certified reference material and various water samples.