STANDARD-FREE METHOD OF QUANTITATIVE ANALYSIS FOR BIO-SAMPLES

Abstract

Internal Standard Method, which has been widely used for quantitative analysis of general bio-samples, requires certain skill in sample preparation since it sometimes accompanies a noticeable error due not only to inaccuracy of weight measurement both of a sample and of an internal standard but also to nonuniformity of the internal standard in the target. In this work, a standard-free method of quantitative analysis, based on the fact that the total yield of continuous x-rays from the sample approximately corresponds to effective weight of the sample, has been developed and applied to some typical bio-samples (NIST Bovine liver, a rat liver and a human serum). As a result, values of concentration obtained by the present method present good agreement with those obtained by the internal standard method. Further, in a case where target preparation is performed by unskilled person, the present method gives better results than those obtained by the internal standard method. It is also found that this method is applicable to almost all soft-tissue samples and, moreover, to targets prepared by a different method.