THE POTENTIAL AND CHALLENGES OF ELEMENTAL SPECIATION BY CAPILLARY ELECTROPHORESIS INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY AND ELECTROSPRAY OR ION-SPRAY MASS-SPECTROMETRY

Capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) and electrospray (ES) or ion spray (IS) mass spectrometry (MS) are recently introduced techniques for elemental speciation. Bot h techniques have the potential for rapid elemental speciation with lo w detection limits. Examples of the use of CE-ICP-MS for elemental spe ciation of positive, neutral and negative species are discussed. Issue s in interfacing CE and ICP-MS are considered briefly. The potential a dvantages and disadvantages of laminar flow in CE-ICP-MS are examined. Potential difficulties in CE-ICP-MS including loss of sample, chemica l matrix effects and changes in speciation during separation are discu ssed. The interpretation of ES or IS-MS spectra and analysis of comple x mixtures are considered. Calibration and chemical matrix effects are assessed. Potential pitfalls of interpreting bare metal ion spectra a s elemental analysis are discussed. The need for fundamental understan ding of the processes that control ES and IS-MS signals is examined. H igh conductivity samples currently present difficulties for CE-ICP-MS or ES and IS-MS. (C) 1998 Elsevier Science B.V.