Analysis of bisphosphonates by capillary electrophoresis-electrospray ionization mass spectrometry

Capillary electrophoresis-electrospray ionization mass spectrometry(CE-ESI- MS) was applied to the direct identification and quantitation of clodronate and its four common impurities. The coaxial interface technique and negati ve ion mode were used in the detection. Ion source parameters and sheath li quid composition were optimized to produce maximum abundance of singly char ged deprotonated molecules used in monitoring. In addition, the effects of electrolyte composition and instrumental parameters of CE on separation wer e studied. The developed method provides high separation power and specific ity to bisphosphonate analysis. In quantitative analysis, the method showed good linearity (r=0.9946-0.9989), satisfactory repeatability (migration ti me variation: RSD=0.43-1.0%, peak area variation: RSD=2.2-9.4%) and suffici ent sensitivity (detection limits: 0.08-0.22 mg ml(-1)) for identification of bisphosphonates from bulk material. (C) 2000 Elsevier Science B.V. All r ights reserved.