A quartz tube atomizer with tungsten coil: a new system for vapor atomization in atomic absorption spectrometry

Abstract

A quartz tube atomizer with a tungsten coil (QTAW) is described for the determination of arsenic in a flow injection hydride generation system. The flow injection system includes a Nafion^® membrane that continuously dries the gaseous species, allowing removal of 4.2 mg min⁻¹ of water, corresponding to an efficiency of 92.7%. The application of this system to the determination of arsenic, using the optimized conditions, shows considerable stability with time, without loss of sensitivity, and it was possible to obtain a calibration curve with a wide range (up to 500 µg l⁻¹), with R² = 0.9998, a limit of detection of 1.5 µg l⁻¹ and an analytical frequency of 60 determinations per hour. The determination of arsenic in samples of mineral and sea-waters, sediment and biological materials, shows good accuracy and precision between the results obtained and the certified values for the recovery of arsenic, with RSD values less than 6%.