Determination of organoarsenic species in blood plasma by HPLC-ICP MS

Abstract

A study of arsenic speciation in blood plasma of patients undergoing renal dialysis has been performed using HPLC coupled with ICP MS. It was found that the only detectable arsenic species present in the plasma was arsenobetaine. The limit of detection using an injection volume of 175 µl was found to be 0.25 ng of arsenic as arsenobetaine. Spiking experiments demonstrated recoveries of approximately 100%. In the absence of certified reference materials or an alternative technique, we believe this was the best way to demonstrate that the method was reliable and accurate. Arsenobetaine concentrations in pre-dialysis plasma were similar to those for the healthy volunteers, although after dialysis the concentrations were significantly reduced. It is thus concluded that, except for a few patients, dialysis removed the arsenobetaine efficiently (hence preventing an accumulation of arsenic) and that no biotransformations were occurring. The exceptions to this conclusion were in a few patients whose arsenobetaine levels increased marginally after dialysis, but this was attributed to the levels both pre- and post-dialysis being very close to the detection limit. Copyright © 1999 John Wiley & Sons, Ltd.