Ultratrace determination of platinum in environmental and biological samples by electrothermal atomization laser-excited atomic fluorescence using a copper vapor laser pumped dye

Abstract

A method to determine ultratrace amounts of platinum in biological and environmental samples based on electrothermal atomization laser-excited fluorescence spectrometry (ETA–LEAFS) is described. A high repetition rate copper vapor laser was employed as a dye laser pump in order to probe more efficiently the platinum atoms generated in a graphite furnace. The L'vov platform, the Katskov type graphite filter and wall atomization were evaluated to obtain the best atomization technique for complex samples. Atomization and ashing temperature studies were performed to obtain the highest signal to noise ratio and/or efficient separation of the analyte from complex matrix components. An absolute limit of detection of 50 fg was achieved based on fluorescence values of aqueous standard solutions. The linear dynamic range was from 1.0 to 250 ng g^–1; the 250 ng g^–1 was limited by detector saturation. A precision of 4.5% at the 10 ng g^–1 level was obtained for water solutions, increasing to 8.0% for complex samples. Recoveries between 100 and 108% were obtained for urine, blood, soil and used auto catalyst pellet samples.