Graphite furnace atomic absorption analysis of marine samples for trace metals

Trace element determinations by graphite furnace atomic absorption spectrometry which are pertinent to the analysis of marine samples are highlighted. Results for the direct introduction of solids, slurries and dissolved samples of fauna, sediments and saline waters are discussed. Examples drawn from recent literature show that typical samples which benefit most from direct solid sampling are those that do not require the very highest accuracy or precision. No clear consensus amongst users of this technique has emerged regarding the choice between peak height or area recording or the need to standardize by aqueous calibration, the method of additions or use of matrix matched solids. Slurry sampling overcomes several limitations associated with direct solid sampling and whereas generalizations serve little purpose in assessing the applicability of the direct solid sampling approach, slurry sampling holds great promise for widespread use. Examples of external and in situ concentration techniques necessary to augment the relative detection power of the system for the analysis of saline waters are also given. These include an examination of “classical” procedures utilizing chelation-solvent extraction, immobilized ligands and precipitation methods as well as techniques which rely on sequestration in the furnace of volatile analyte species generated in external cells.