LIQUID-CHROMATOGRAPHIC DETERMINATION OF AZIDOTHYMIDINE IN HUMAN PLASMA USING ONLINE DIALYSIS AND PRECONCENTRATION OF A SILVER(I) - A THIOL STATIONARY PHASE

An automated method is described for the routine determination of 3′-azido-2′,3′-dideoxythymidine (AZT), the best known drug against acquired immunodeficiency syndrome (AIDS). The method is based on on-line dialysis to remove matrix macromolecules, followed by selective preconcentration and clean-up with a silver(I)-thiol stationary phase. After desorption of the solute with a small plug of perchloric acid, chromatography is applied using an octadecyl-modified silica column. Using UV absorbance detection at 269 nm, the minimum detectable concentration in plasma is 20 ng ml-1 (600-μl sample). The within-day reproducibility at the 20 ng ml-1 level is 4.4% and at least 128 samples can be analysed unattendedly without exchanging the dialysis membrane, the precolumn or the analytical column. © 1990.