ELEMENT ANALYSIS OF INHOMOGENEOUS SAMPLES BY LASER-ABLATION ICP MASS-SPECTROMETRY

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS ) has been used for the determination of selected elements in heteroge neous powdered soils. The precision of the method essentially depends on the homogeneity of the samples. Therefore the influence of sample i nhomogeneity on the precision of analytical results has been checked. The statistical evaluation was carried out using a correlation functio n. In the context of the described experiments, it is necessary to ana lyze a volume of about 20 mm3 in order to obtain reliable information on the bulk composition of the heterogeneous samples. This corresponds to about 50 craters, each with a depth of 1 mm. The results can be us ed to calculate certain analytical parameters, particularly the sample homogeneity, depending on the necessary analytical volume and the rep resentative mass for the quantitative analysis under previously define d conditions. In addition to these calculations, analytical experiment s have been carried out which confirm the applicability of this approa ch.