Determination of mercury in water samples by electrochemical cold vapor generation coupled to microstrip microwave induced helium plasma optical emission spectrometry

A new combination of flow-through electrochemical mercury cold vapor generation using a microstrip microwave plasma optical emission spectrometry is described in this work. This coupled technique has been optimized to attain the maximum sensitivity for Hg determinations in aqueous solutions and the lower limits of detection. A laboratory constructed thin-layer flow-through hydrogen remover (inner volume of 2x150 mu L) was used. A limit of detection of 1.1 ng.mL(-1) (peak height, 3 sigma criterion) for mercury was obtained with the proposed method when using electrochemical mercury cold vapor generation. Further, the results obtained with spiked SRM NIST 1640 and SRM NIST 2781 were verified by ICP-OES and a good agreement at the concentration levels of 2.72 +/- 037 mu g.g(-1) and 2.80 +/- 025 mu g-g(-1) was obtained. The repeatability at the 50 ng-mL(-1) level was better than 2.7% (RSD). (C) 2012 Elsevier B.V. All rights reserved.