Combustion and volatilisation of solid samples for direct atomic absorption spectrometry using silica or nickel tube furnace atomisers

Abstract

A technique for the direct analysis of solids by atomic absorption spectrometry (AAS) is described. The sample, 0.1–2.0 mg, is weighed on to a graphite platform which is located at the focus of three infrared lamps. The combustion of the sample is started by a flash from the lamps and the smoke, which contains the more volatile elements, mercury, cadmium, lead, zinc, thallium, bismuth and copper, is transported to a T-tube, that is heated by either an air-acetylene flame or an electric coil, in which atomisation occurs and an atomic absorption spectrometric determination is made. Variable conditions, viz., the air flow, tube temperature and matrix effects, were studied. Good agreement with the concentrations determined by graphite furnace AAS in solution or with the recommended concentrations in different biological reference materials was obtained. The sensitivities obtained, in peak area, were about two orders of magnitude better than those of the conventional flame AAS technique. The proposed device is easily adapted to any atomic absorption spectrometer.