QUANTITATION METHODS USING LASER-ABLATION ICP-MS .1. ANALYSIS OF POWDERS

Laser Ablation ICP-MS offers the capability of direct analysis of conductive and non-conductive samples. However the quantitation capabilities of LA-ICP-MS are often questioned. In order to qualify the term quantitation, different methods, appropriate for laser ablation, are discussed. Measurements on different sample matrices were performed both semiquantitatively and quantitatively using standards with the same matrix. Additionally, the use of an internal standard, a minor isotope of the matrix element or a known concentration of a trace or a minor element can be selected as an aid to quantitation. In cases where there is no certified element concentration available, a ''user value'' for the LA-ICP-MS sensitivity can be chosen. These different methods of quantitation are compared and the rationale behind each approach is discussed.