Qualitative and Semiquantitative Analysis

Abstract

Many analytical problems require only qualitative or semiquantitative, rather than quantitative, analysis of the sample(s)—that is, detection or identification of the elements present, or estimation, rather than determination, of their concentrations. A quantitative x-ray spectrometric analysis usually gives analyte concentration within a relatively narrow known range of accuracy as derived from precisely measured and carefully corrected intensity data, and from calibration data from standards very similar to the samples in analyte concentration and matrix composition. A semi-quantitative x-ray spectrometric analysis usually gives analyte concentration as derived from intensities measured with speed and convenience, rather than precision, as primary objectives, and from standards applicable to a variety of related sample types. If samples and standards are very similar, a semiquantitative analysis may give high accuracy, but the more they differ, the poorer is the accuracy.