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 2 × 150 μL) was used.A limit of detection of 1.1 ng·mL− 1 (peak height, 3σ 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 ± 0.37 μg·g− 1 and 2.80 ± 0.25 μg·g− 1 was obtained.The repeatability at the 50 ng·mL− 1 level was better than 2.7% (RSD).

► A novel flow-through electrochemical mercury cold vapor generation was developed.
► The coupled technique was optimized for maximum sensitivity for Hg determination.
► A laboratory constructed thin-layer flow-through hydrogen remover was used.
► The results obtained with spiked SRMs were verified by ICP–OES.