Elemental Speciation Measurements with Electrospray Mass Spectrometry: An Assessment

Electrospray mass spectrometry (ES-MS) is shown to be suited for the direct determination of ionic species in solution. Examples used in this investigation of ES-MS for elemental speciation determinations included several inorganic ionic species of chlorine, iodine, sulfur, and iron. These species were differentiated on the basis of differences in the molecular form and/or the oxidation state of the analyte ion. The inorganic complexes of silver-cyanide and iron-fluoride were also measured in this assessment. Finally it is shown that ES-MS is applicable to the determination of organometallic compounds. While ES-MS is not an ideal speciation technique, there is considerable evidence to indicate that ES-MS can become an invaluable tool with which species distributions in a wide range of sample types may be probed.