Clinical Chemistry, Vol 35, 127-130, Copyright © 1989 by American Association for Clinical Chemistry

Improved determination of vanadium in biological fluids by electrothermal atomic absorption spectrometry

O Ishida, K Kihira, Y Tsukamoto and F Marumo
Kitasato Biochemical Laboratories, Bristol-Myers, Kanagawa, Japan.

We made sensitive and accurate electrothermal atomic absorption spectrometric measurements of vanadium in small volumes of serum. The wet-digested sample was extracted into an organic solvent, with N- benzoyl-N-(o-tolyl)hydroxylamine (BTA) as the chelating reagent. After evaporating the solvent, we dissolved the residue in acetic acid, and injected a 60-microL aliquot into a graphite furnace. In this way we could measure vanadium concentrations as low as 80 ng/L in 4 mL of serum. The within-run CV was 3.3% for serum, 7.7% for urine. Analytical recoveries of vanadium added to serum and urine were 90.3% and 90.8%, respectively. We measured vanadium concentrations in sera from 64 healthy persons (group 1), 15 nondialyzed uremic patients (group 2), and 11 hemodialyzed patients (group 3). The highest concentration of vanadium in group 1 was 240 ng/L; about 60% of the values for this group were less than 80 ng/L. In group 3, the vanadium concentrations were extremely high (15 +/- 14.2 micrograms/L, mean +/- SD), less so (but still above normal) in group 2 (1.58 +/- 3.16 micrograms/L).