Studies of a low-noise laminar flow torch for inductively coupled plasma atomic emission spectrometry. Part 1. Fundamental characteristics

Abstract

The fundamental properties of the laminar flow torch (LFT) designed in our laboratory are described. Noise power spectra are presented which show that the principle source of noise in a conventional tangential flow torch (TFT) has been removed in the laminar flow torch. Spatial profiles of Ca atom and ion emission intensities are observed to be displaced towards the induction coil in comparison with those in a conventional tangential flow torch. Electron densities measured in the LFT are lower than those in the TFT but Ca ion to atom ratios are higher in the LFT and hence ionisation temperatures are comparable to those in the TFT. Detection limits in the LFT are therefore superior by an order of magnitude compared with the TFT.