Optical emission spectrometry with microwave induced plasmas in structures based on microstrip technology for the determination of Hg, As, Sb, Cl, Br and S with the aid of cold vapour generation techniques

Abstract

The use of two types of microstrip plasmas (MSP) inside and exiting the sapphire wafer with Ar and He as working gases at a forward power of 40 W for the determination of metals and non-metals, such as Hg, As, Sb, Cl, Br, S and C in their volatile form using cold vapour generation techniques with SnCl2 as reducing agent, chemical and electrochemical hydride generation as well as redox reactions coupled to optical emission spectrometry is investigated in the present work. The vapour generation systems were determined with a univariant procedure for the different parameters such as stabilizing reagent substances, reagent concentrations as well as reagent and gas flow rates for an efficient production and separation of the volatile analyte species to be introduced into the MSP source. The use of a miniaturized spectrometer, USB2000 Ocean Optics, is shown to be advantageous due to the affordance of the systems developed for micrototal analysis systems (µ-TAS), to portability, to lower working costs, to less use of reagents and to fast chemical analyses. Studies for the removal of the water vapours were performed. The use of a tank filled with H2SO4 was found to be the most reliable way to separate the analyte from the moisture due to its long-term life ad effectiveness