CAPILLARY ELECTROPHORESIS INDUCTIVELY-COUPLED PLASMA SPECTROMETRY FOR RAPID ELEMENTAL SPECIATION

Initial results using the combination of capillary electrophoresis (CE) and sensitive, element-selective, inductively coupled plasma (ICP) optical emission spectrometry (OES) and mass spectrometry (RIS) for rapid elemental speciation are reported. An interface to produce a fine aerosol that is efficiently transported from the end of the electrophoresis capillary to the ICP with negligible liquid dead volume was developed, By using element-selective detection provided by ICP spectrometry, electrophoretic resolution could be traded off for rapid analysis times, CE-ICP spectrometry was used for elemental speciation of inorganic ions with different charge states, organometallic species, and metal-ligand complexes. CE-ICP spectrometry may also be useful to rapidly determine metal-ligand complex stability constants, Analysis times were generally less than 2 min. Detection limits for CE/ICP-OES were within a factor of 19 of those typically obtained using ICP-OES for elemental analysis (without speciation). Detection limits for CE/ICP-MS were generally a factor of 60 times higher than those typically obtained by using ICP-MS for elemental analysis (without speciation), However, the detection limits for CE/ICP-MS were as low as 0.06 ppb, which corresponds to 8 fg (90 amol) of Sr in the injected sample, Peak area and elution time reproducibility were typically better than 3% relative standard deviation for successive injections.