A new approach of direct sample-digestion before vaporization for determination of a metal in rocks by inductively coupled plasma atomic emission spectrometry

A new approach to sample digestion, subsequent vaporization and introductio n to an inductively coupled plasma (ICP) atomic emission spectrometer was d eveloped for the direct determination of magnesium. To each small sample cu vette made of tungsten, a ground rock sample was precisely weighed. The cuv ette was situated on a tungsten boat furnace. Ammonium fluoride solution wa s added to the cuvette as a chemical modifier. After the on-furnace digesti on has been completed, the analyte, magnesium, in the cuvette was vaporized and introduced into the ICP atomic emission spectrometer. Since the powder ed samples were wet-digested in the sample cuvettes prior to vaporization, they could be analyzed by using a calibration curve prepared from aqueous s tandard solutions. This method was applied to the determination of magnesiu m in several standard reference materials with satisfactory results.