Cloud Point Extraction: Application to Heavy Metals Analysis

Abstract

The applications of extraction method based on cloud point extraction for the analysis of heavy metals in environmental and various types of sample matrices have been receiving more attention at present. The main advantages of cloud point extraction as compared to the liquid-liquid extraction are that it can improve the limit of detection, the enrichment factor and the sensitivity of the analysis. The sample preparation provides low cost, simple and rapid procedures, and avoids using large amount of toxic organic solvents. The extraction procedure consists of three steps: 1) the solubilization of interested analytes in the micelle aggregates of surfactant, 2) clouding stage of surfactant at cloud point temperature and 3) the phase separation of surfactant from the solution phase prior to analysis. In this article, the principle of cloud point extraction using surfactants is presented. Factors affecting cloud point extraction and applications for trace heavy metal analysis in various types of sample matrices e.g. environmental and clinical samples, including the speciation of some heavy metals are reviewed.