Determination of bisphosphonates by ion chromatography–inductively coupled plasma mass spectrometry

Abstract

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 N 16 O + , 14 N 16 O 1 H + , and 12 C 1 H 3 16 O + ), a detailed study of the influence of plasma parameters on phosphorus and background signal was performed.