On-line Removal of Anions for Plant Analysis by Inductively Coupled Plasma Mass Spectrometry

Abstract

The multi-element determination of B, Al, Cu, Zn, Mn, Fe, Cr, Cd, Pb and S in plant digests by ICP-MS with on-line removal of anions is presented. A column with the anionic resin AG1-X8 was placed in a flow system to remove mainly sulfate and chloride while the solution was flowing to the ICP-MS system for the determination of the other elements. Subsequently, the sulfur retained by the column was eluted and determined at m/z 48. The effect of perchlorate on sulfate retention was studied. Interferences on isotopes ⁶⁵ Cu, ⁶⁴ Zn, ⁶⁷ Zn and ⁵³ Cr were minimized using this approach. The analytical range was from 0.2 to 1.0% S for the vegetable samples analyzed. The detection limit was 0.02% S (dry basis). Results from reference materials (NIST SRM 1573a Tomato Leaves and ORSTOM palmier and pommier golden) were in agreement with certified values at the 95% confidence level.