title: Determination of pamidronate in urine by ion-pair liquid chromatography after derivatization with 1-naphthylisothiocyanate.
abstract: A sensitive method for the determination of pamidronate disodium [(3-amino-1-hydroxypropylidene)bisphosphonate, APD] in urine has been developed and validated. The procedure involves a triple co-precipitation with calcium phosphate, solid-phase extraction on a quaternary ammonium column, derivatization with 1-naphthylisothiocyanate and ion-pair liquid-liquid extraction. From the two reaction products, naphthylthiocarbamyl-APD is converted into the other, naphthylcarbamyl-APD, by an oxidative desulphuration with hydrogen-peroxide prior to analysis by ion-pair HPLC and fluorescence detection at 285/390 nm. The method has a coefficient of variation of 7% for the intra-assay precision of 99 ng ml-1 APD and 11% for the inter-assay precision. The lower limit of quantification is 3 ng ml-1 APD in 2.5 ml of human urine.
authors.affiliation: Department of Clinical Pharmacy and Toxicology, Leiden University Hospital, The Netherlands.
authors.forename: R W
authors.initials: RW
authors.lastname: Sparidans
authors.forename: J
authors.initials: J
authors.lastname: den Hartigh
authors.forename: J H
authors.initials: JH
authors.lastname: Beijnen
authors.forename: P
authors.initials: P
authors.lastname: Vermeij
mesh_terms: D015058:1-Naphthylisothiocyanate / Q000737:chemistry*; D002138:Calibration; D011232:Chemical Precipitation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002940:Circadian Rhythm; D004164:Diphosphonates / Q000737:chemistry / Q000652:urine*; D006801:Humans; D009994:Osmolar Concentration; D000077268:Pamidronate; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D004164:Diphosphonates; D015058:1-Naphthylisothiocyanate; D000077268:Pamidronate