ELECTROSPRAY MASS-SPECTROMETRY AS A TECHNIQUE FOR THE ELEMENTAL ANALYSIS OF METALS AND ORGANOMETALS

An investigation of an in-house constructed electrospray (ES) ion sour ce and interface has been carried out with the focus on elemental anal ysis. An evaluation of the 29, 30 and 31 gauge capillary sizes for the ES source is presented. For multielement solutions of alkali metals, alkaline earth metals and transition metals studied in the bare metal ion mode, the smaller 30 gauge capillary improved the detection limits by an order of magnitude over those of the larger 29 gauge. The 31 ga uge was too fragile for easy handling. The ion-cluster modes of Cr-II, Cr-III and Co-II were investigated and the resulting spectra indicate the possibility of attaining speciation information with this set-up. Matrix effects on the analyte signal of a multielement solution of tr ansition metals using the 29 and 30 gauge capillaries are discussed. T he same trend is observed with both capillaries where the signal inten sity improves with the addition of 0.15% and 0.30% total dissolved sol ids. At higher concentrations of total dissolved solids signal suppres sion is seen. Additionally, ES-MS was demonstrated as an elemental ana lysis tool for the study of the bare metal ion mode of larger organome tallics, mainly organolead compounds and metalloporphyrins.