Sample preconcentration and matrix removal techniques for ultra-trace determinations by inductively coupled plasma mass spectrometry (ISP-MS)

Abstract

This thesis describes the design and application of a laboratory-based matrix removal/preconcentration system using an iminodiacetate chelating ion exchange reagent. The chelating ion exchange reagent selectively isolates trace elements in solution from the matrix (macro levels of Ca, Mg, Na and various anions in solution) of analytical samples. This leads to reduced matrix and spectral interferences and improved detection limits for atomic spectrometric determinations. The system is used in conjunction with a low-flow microconcentric nebuliser and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The analytical features of the system are described. These include the pH dependence of analyte recovery, the reproducibility and detection limits achievable by this technique. The system is evaluated for the determination of trace elements in bivalve shells, mineral waters and certified water reference materials. Results of an extensive study profiling trace element constituents in bivalve shells around the Irish coast are presented. The results provide baseline data on the impact of trace element pollution on the Irish marine environment. In particular, the anthropogenic impacts of trace element pollution from the dumping of sewage sludge and dredge material at sea is dicussed.