Analysis for platinum in biological material by flameless atomic absorption spectrometry

A method for determining platinum in biological materials by flameless atomic absorption spectrometry has been developed for use in pharmacological studies of platinum antitumor compounds. Tissue digests are analyzed in a heated graphite atomizer, with use of background correction and ramp temperature charring. We have overcome problems of apparent loss of platinum in Pt-supplemented tissue samples with time and of difficulty in analyzing tissue lipid. The validity of the assay was verified by injecting rats with radiolabeled cis-dichlorodiammineplatinum (II), then measuring platinum in tissues by gamma scintillation spectrometry and flameless atomic absorption spectrometry. Correlation between the two methods was excellent. The limit of the assay in its present form is about 0.1 migrogram/gram of wet tissue.