Determination of As, Hg, Se and Sn in sediment slurries by CVG-ETV-ICP-MS with trapping in an Ir treated graphite tube and calibration against aqueous standards

A method for the simultaneous determination of As, Hg, Se and Sri in sediment slurries using chemical vapor generation (CVG), in situ trapping electrothermal vaporization inductively coupled plasma mass spectrometry, is proposed. The vapors produced by the reaction of the sample slurry with the reducing agent are transported to the vaporizer and trapped at 150 degreesC in a graphite tube, treated with Ir as a permanent modifier, before vdporization at 2000 degreesC and transport to. the plasma. The accuracy of the method was assured by the analysis of certified reference sediment samples, using external calibration with aqueous solutions, prepared in the same medium and subject to the same, CVG and trapping procedure as the slurries. The obtained concentrations were in agreement with the certified values, using the t-Student test for a confidence level of 95%. The detection limits, in ng g(-1), were: 0.8 for Hg, 0.04 for As, 0.01 for Se and 0.30 for Sn.