Flow injection hydride generation and on-line W-coil trapping for electrothermal vaporization dielectric barrier discharge atomic emission spectrometric determination of trace cadmium.

A fast, low-cost and sensitive method for the determination of trace cadmium was developed by using a miniaturized dielectric barrier discharge microplasma atomic emission spectrometer coupled with a tungsten coil (W-coil) for on-line hydride generation trapping-electrothermal vaporization. Total sample throughput can be greatly improved through the adoption of a horizontally fixed W-coil and the flow injection mode. In addition, the horizontally fixed W-coil and an inserted quartz capillary for on-line trapping contributed to stable and good signal even at a high gas flow rate when volatile cadmium species were trapped, and less sample-consuming and time-saving can be realized in this work. Compared to direct injection, the sensitivity and the LOD were improved by 29- and 38-fold, respectively. The proposed method provides a promising approach to develop a miniaturized instrumentation for highly sensitive detection of trace elements.