Evaluation of the capacitively coupled helium microwave plasma as an excitation source for the determination of inorganic and organic tin

Abstract

A capacitively coupled He microwave plasma (He CMP) with a tubular Ta electrode was investigated as an excitation source for atomic emission spectrometry. Spatial distributions of the He plasma support and Sn molecular emission intensities were obtained, and intense atomic emission was found in the plasma centre. The He excitation temperature was almost the same as that of the microwave-induced plasma. Analytical performance was evaluated for the determination of inorganic Sn followed by hydride generation and collection in a cold trap, and also for the speciation and determination of butyltin compounds by interfacing the He CMP with a gas chromatography system. Several experimental parameters were optimised, and the signal to background ratio, signal to noise ratio, reproducibility and limit of detection were obtained in each instance.