Simplified cloud point extraction-inductively coupled plasma mass spectrometry for the preconcentration/analysis of ultra-trace gold

A new cloud point extraction method for the preconcentration of ultra-trace gold as a prior step to its determination by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. The method is based on the cloud point extraction (CPE) of gold in the non-ionic surfactant Triton X-114 without a chelating agent. The parameters of CPE were investigated in detail. At optimum conditions, the linear range of 5.0-200.0 ng L-1 of Au(III) and the detection limits of 1.1 ng L-1 for Au(III) along with enrichment factors of 7.5, were obtained. The proposed method was applied to determination of ultra-trace amounts of gold in water samples with satisfactory results. (C) 2010 Elsevier Ltd. All rights reserved.