Determination of trace amounts of calcium by laser-enhanced ionisation spectroscopy in flames

Abstract

Use of two-step excitation for the determination of calcium in flames is described. A detection limit of 2 × 10^–5µg ml^–1 was attained using acetylene as the fuel gas. Different schemes for the excitation of calcium atoms were examined and the effects of the experimental conditions on the analytical signal were studied. The influence of aluminium on the determination of calcium was also investigated, in addition to the means of its elimination. With prior separation of calcium from the aluminium, it was possible to determine calcium in aluminium alloys at levels down to 0.001%.