The use of a modified Multimode Sample Introduction System for the simple and rapid determination of cadmium by chemical vapour generation atomic absorption spectrometry

Abstract

A cold vapour (CV) generation system incorporating a modified version of a Multimode Sample Introduction System (MSIS™) was investigated for the determination of cadmium by atomic absorption spectrometry (AAS). The system allowed for the use of the relatively high concentrations of reagents required for efficient production of volatile cadmium without the significant bubbling, frothing, and associated liquid transport problems common to conventional gas–liquid separators while maintaining a low volume. The low volume produced narrow peaks (approximately 5 s base peak width). A detection limit of 0.026 μg L −1 (3s) was found with a precision of 2.5% for a 0.5 μg L −1 standard ( n=4) and a linear dynamic range up to approximately 10 μg L −1. The addition of thiourea, cobalt, and nickel was found to overcome interferences and produce good agreement between experimental and certified values for Natural Water and Mussel Tissue standard reference materials (SRM).