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

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 th at the only detectable arsenic species present in the plasma was arsenobeta ine, The limit of detection using an injection volume of 175 mu l was found to be 0.25 ng of arsenic as arsenobetaine, Spiking experiments demonstrate d recoveries of approximately 100%, In the absence of certified reference m aterials or an alternative technique, we believe this was the best way to d emonstrate that the method was reliable and accurate, Arsenobetaine concent rations in pre-dialysis plasma were similar to those for the healthy volunt eers, although after dialysis the concentrations were significantly reduced , It is thus concluded that, except for a few patients, dialysis removed th e arsenobetaine efficiently (hence preventing an accumulation of arsenic) a nd that no biotransformations were occurring. The exceptions to this conclu sion were in a few patients whose arsenobetaine levels increased marginally after dialysis, but this was attributed to the levels both pre- and postdi alysis being very close to the detection limit. Copyright (C) 1999 John Wil ey & Sons, Ltd.