ESI-QIMS investigation of Sr, Rb, and crown ether mixture solutions

by Song, S.; Liyanage, R.; Lay, J. O.; Warby, R.; Koizumi, H.

The isotope distribution of Sr, alternatively (87)Sr/(86)Sr ratio frequently reported in geologic investigations, is obtained by direct electrospray ionization of aqueous samples containing Sr(II), Rb(I) with added 18-crown-6 (18c6) [1,4,7,10,13,16-Hexaoxacyclooctadecane C(12)H(24)O(6) m/z 264.3]. At relatively high concentrations of Sr and Rb, we observed favorable formation of Sr(2+)(18c6)(2) and Rb(+)(18c6) rather than Sr(2+)(18c6) complexes. Significant Sr(2+)(18c6)(2) suppression observed in post column addition of samples into water solvent disappeared when formic acid was present in the carrier solvent. Electrospray ionization-quadrupole-ion trap mass spectrometry (ESI-QITMS) successfully obtained the expected isotope distribution of Sr showing no interference from Rb without chromatographic separation of (87)Sr and (87)Rb necessary in ICP-MS studies.

Journal
Analytical Letters
Volume
44
Issue
12
Year
2011
Start Page
2170-2181
URL
https://dx.doi.org/10.1080/00032719.2010.546026
ISBN/ISSN
1532-236X; 0003-2719
DOI
10.1080/00032719.2010.546026