DETERMINATION OF SILICON IN BIOLOGICAL SAMPLES USING ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

A method for the determination of silicon in plasma and urine is described using atomic absorption spectrometry with a graphite furnace. The procedure was carried out with a Perkin Elmer Zeeman-3030 instrument that had been modified to reduce silicon contamination by replacing the silicone rubber components. Interferences arising from the plasma matrix have been eliminated by the use of a chemical modifier in conjunction with a molybdenum treated L'vov platform and graphite tube. A procedure is also described for obtaining blood samples that are free of silicon contamination. The mean plasma silicon value for 15 normal individuals was 0.17 +/- 0.10 [standard deviation (SD)] mg I-1; the mean urine concentration was 11.0 +/- 7.5 (SD) mg I-1.