Analysis of small samples of brasses by inductively coupled plasma-optical emission spectrometry and their classification by two pattern-recognition techniques

As part of its evaluation in the analysis of evidential materials, inductively coupled plasma-optical emission spectrometry (ICP-OES) has been used to obtain quantitative data for up to eight elements in 100-µg samples of a collection of brasses. The precision and accuracy of the method were monitored by repeat analyses of a certified brass standard. The quantitative data from the 37 brasses form a reference collection that will assist forensic scientists in the interpretation of certain alloy analyses. Methods for the objective classification of the samples were investigated by applying hierarchic clustering and non-linear mapping techniques to the data set.