FLAMELESS ATOMIC-ABSORPTION SPECTROMETRY AFTER ACID MICROWAVE DIGESTION - A PRECISE AND SENSITIVE METHOD FOR THE DETERMINATION OF RUTHENIUMIN BIOLOGICAL SAMPLES

We set up a rapid, sensitive and precise method for ruthenium determin ations in serum, tumor tissue, liver and kidney. We mineralized biolog ical tissues by heating them in a microwave oven with 70% HNO3 and 30% H2O2. Serum samples were diluted with a solution of 0.01% of Triton X -100 in 0.1% HNO3. Ruthenium concentrations in the samples were determ ined by electrothermal atomic absorption spectrometry (ETAAS) using a calibration curve. In our given concentration range (max 150 ngRu/ml), the calibration curves are linear (r = 0.9998). In biological tissues , the precision of the method was less-than-or-equal-to 10%, recovery was greater-than-or-equal-to 95% and the limit of quantitation was 40 ngRu/g. In serum, precision was less-than-or-equal-to 6%, recovery gre ater-than-or-equal-to 98.5% and limit of quantitation was 2 ngRu/ml.