Sensitive determination of Hg together with Mn, Fe, Cu by combined photochemical vapor generation and pneumatic nebulization in the programmable temperature spray chamber and inductively coupled plasma optical emission spectrometry

Publication date: 15 May 2017
Source:Talanta, Volume 167
Author(s): Jacek Giersz, Magdalena Bartosiak, Krzysztof Jankowski
Continuous photo-induced generation of mercury cold vapor has been successfully coupled with conventional pneumatic nebulization in programmable temperature spray chamber (PCVG–PN–PTSC) allowing fast, sensitive and easy multi-element analysis. The applied technique enabled simultaneous determination of non-volatile forming elements (Fe, Cu, Mn) and volatile Hg, while 15%v/v formic acid is present in the sample. PTSC elevated temperature (40°C) causes partial conversion of sample matrix into vapor form, thus improving plasma robustness. The efficiency of Hg vapor generation and its transport to the plasma is close to 100%. Moreover, spray chamber temperature stabilization improved the precision of the measurements (Hg signal RSD below 0.5%). The achieved limit of detection for Hg (90pgmL⁻¹) at 194.23nm with no monochromator purge is better by almost two orders of magnitude than that obtained by conventional PN-ICP-OES. On the other hand, LODs for non-vapor forming elements are comparable to those obtained with pneumatic nebulization. The linear dynamic ranges for all examined elements are at least three orders of magnitude up to 1000ngmL⁻¹. None mutual interference between examined analytes (Hg, Fe, Cu, Mn) has been observed. The method was validated by the analysis of two CRM materials of different matrix composition (waste water ERM CA713 and estuarine sediment ERM CC580) giving satisfactory results. As low as 2 ppb of Hg can he directly determined in waste water. The proposed procedure uses mild reagents and allows for fast multi-element analysis, and matches green chemistry requirements.

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