Article ID Journal Published Year Pages File Type
1245555 Talanta 2008 5 Pages PDF
Abstract

Cloud point extraction (CPE) has been used for the pre-concentration of mercury, after the formation of a complex with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (5-Br-PADAP), and later analysis by electrothermal atomic absorption spectrometry (ETAAS) using polyethyleneglycolmono-p-nonyphenylether (PONPE 7.5) as surfactant. The chemical variables affecting the separation step were optimized. Under the optimum conditions, i.e, pH 8.5, cloud point temperature 80 °C, 5-Br-PADAP = 4 × 10−5 mol L−1, PONPE 7.5 = 0.2%, sample volume = 1.0 mL, an enhancement factor of 22-fold was reached. The lower limit of detection (LOD) obtained under the optimal conditions was 0.01 μg L−1. The precision for 10 replicate determinations at 2.0 μg L−1 Hg was 4.0% relative standard deviation (R.S.D.). The calibration graph using the pre-concentration system for mercury was linear with a correlation coefficient of 0.9994 at levels near the detection limits up to at least 16 μg L−1. The method was successfully applied to the determination of mercury in biological samples and in certified reference material (QC METAL LL3).

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
Authors
, , , , ,