Determination of bisphosphonate by ion chromatography-inductively coupled mass spectrometry

An ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS) was introduced in the analysis of bisphosphonates. Two compounds (alendronic acid and etidronic acid) were separated on a Dionex AS-7 anion-exchange column with dilute nitric acid employed as the mobile phase. The analytes were detected at m/z 31, as they contain phosphorus. The detection limits achieved were 0.20 mg l(-1) for alendronic acid and 0.05 mg l(-1) for etidronic acid. Since the determination of phosphorus by ICP-MS is difficult due to polyatomic interferences at m/z 31 (15 (NO+)-O-16, N-14 O-16 H-1(+), and (CH3O+)-C-12-H-1-O-16). a detailed study of the influence of plasma parameters on phosphorus and background signal was performed. (C) 2004 Elsevier B.V. All rights reserved.