SEMIAUTOMATIC LIQUID-CHROMATOGRAPHIC ANALYSIS OF PAMIDRONATE IN SERUMAND CITRATE PLASMA AFTER DERIVATIZATION WITH 1-NAPHTHYLISOTHIOCYANATE

The semi-automatic method for the determination of the bisphosphonate pamidronate in serum and citrate plasma involves a manual protein prec ipitation with trichloroacetic acid and a manual coprecipitation of th e bisphosphonate with calcium phosphate, followed by an automated soli d-phase extraction on anion-exchange columns. After off-line evaporati on of the extract under nitrogen and reconstitution in water, the auto matic procedure is continued by automatic derivatization with 1-naphth ylisothiocyanate, ion-pair liquid-liquid extraction and a treatment wi th hydrogen peroxide, prior to analysis by ion-pair HPLC and fluoresce nce detection at 285/390 nm. The intra-and inter-day precisions are 1. 3 and 7%, respectively, for a standard of 100 ng ml(-1) pamidronate in serum; the average accuracy for this standard is 107%. The lower limi t of quantification is 20 ng ml(-1) pamidronate in 1 ml of human serum . (C) 1998 Elsevier Science B.V.