SENSITIVE METHOD FOR ANALYSIS OF STRONTIUM IN HUMAN AND ANIMAL PLASMABY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROPHOTOMETRY

For long-term pharmacokinetic studies in humans as well as in experime ntal animals, an analysis of strontium (Sr) with a low detection limit and high sensitivity is necessary. The data presented here describe t he optimization of the furnace program and sample handling for measuri ng Sr in plasma by using graphite furnace atomic absorption spectropho tometry. The method was validated and applied to studies on the pharma cokinetics of SrCl2 in humans and rats. Calibration curves were linear up to 57.1 nmol/L. The limit of detection and lower limit of quantifi cation were 0.21 and 0.57 nmol/L, respectively. Reciprocal sensitivity was 0.53 nmol/L Sr at A = 0.0044. The intraassay precision was 2.2%, 1.5%, and 1.1% (n = 6) at 4.57, 22.7, and 49.2 nmol/L Sr, respectively . At these concentrations, the interassay precision and recovery were 0.7%, 1.5%, and 1.8% and 100.4%, 99.1%, and 100.6% (n = 12), respectiv ely. The endogenous Sr concentration in human plasma samples was 0.27 +/- 0.07 mu mol/L (n = 18). Pharmacokinetic studies in a human volunte er and in rats demonstrated that this procedure was suited for measuri ng low Sr concentrations and was applicable to small sample volumes.