SREL Reprint #2613

Detection of inorganic ions from water by electrospray ionization-ion mobility spectrometry

Heather M. Dion1,2,3, Luke K. Ackerman2,3, and Herbert H. Hill Jr.2,3

1Savannah River Ecology Laboratory, University of Georgia, Savannah River Site, Drawer E, Aiken, SC 29802, USA
2Department of Chemistry, P.O. Box 644630, Washington State University, Pullman, WA 99164-4630, USA
3Center for Multiphase Environmental Research, P.O. Box 642710, Washington State University,
Pullman, WA 99164-2710, USA

Abstract: The results from this study illustrate the first time electrospray ionization-ion mobility spectrometry (ESI-IMS) has been used to separate inorganic cations in aqueous solutions. Using ESI-IMS nine inorganic cation solutions were analyzed. Counter ions affected both the sensitivity and the identity of the response ions. Aluminum sulfate, lanthanum chloride, strontium chloride, uranyl acetate, uranyl nitrate, and zinc sulfate produced spectra containing a single response ion. Aluminum nitrate and zinc acetate solutions produced multiple ion peaks, which increased the detection limits and the difficulty of identification. Cation detection limits ranged from 0.16 to 13 ng µl-1 depending on the solution studied. The identities of the ion species detected were unconfirmed, but mass spectrometry literature suggested the detection of positively charged cation-solvent or cation-solvent-anion complexes. Finally, cations from strontium and lanthanum chloride solutions were separated with a resolution of 2.2. The results from this study suggest that ESI-IMS has potential as a field technique for the detection of metal cations and their complexes in the environment.

Keywords: Ion mobility spectrometry; Electrospray ionization; Inorganic cation detection

SREL Reprint #2613

Dion, H. M., L. K. Ackerman, and H. H. Hill, Jr. 2002. Detection of inorganic ions from water by electrospray ionization-ion mobility spectrometry. Talanta 57:1161-1171.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).