ONLINE SOLID-PHASE CHELATION FOR THE DETERMINATION OF 8 METALS IN ENVIRONMENTAL WATERS BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

A low-pressure method for the on-line preconcentration of analytes and elimination of matrix elements prior to determination by inductively coupled plasma mass spectrometry (ICP-MS) is described, The method red uces the concentrations of matrix elements in samples to levels that d o not interfere with the determination of the first row transition ele ments at trace levels. The method also reduces biases caused by differ ences between samples and standards by delivering the analytes to the ICP-MS instrument in a consistent nitric acid matrix, A commercially a vailable low-pressure sample manipulation system was used to perform s olid-phase chelation on an iminodiacetate column, The effectiveness of the method is demonstrated for the determination of Cd, Co, Cu, Mn, N i, Pb, U and Zn in the certified reference materials CASS-2, Near Shor e Sea-water; NASS-4, Open Ocean Sea-water; and the Standard Reference Material 1643b, Trace Elements in Water, The volume of sample preconce ntrated was varied in order to optimize the analyte signal, The detect ion limits for 10 mi samples ranged from 0.8 ng l(-1) for Co to 40 ng l(-1) for Cu and Zn.