PRECONCENTRATION OF TRACE-ELEMENTS IN POTABLE LIQUIDS BY MEAS OF A LIQUID MEMBRANE EMULSION FOR FLAME ATOMIC-ABSORPTION DETERMINATION

A liquid membrane emulsion was developed for the simultaneous extraction and preconcentration of traces of Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn in potable liquids. After preconcentration, the eight elements were determined by flame atomic absorption spectrometry (FAAS). The results of analyses of potable water, beer and soft drinks, each from five or six different sources are listed. Data from the preconcentration method were compared with corresponding data obtained from the direct determination of the elements by graphite furnace atomic absorption spectrometry (GFAAS). Differences in results for trace elements between the liquid membrane emulsion-FAAS method and the GFAAS method were in the ranges of +/- 10% (water), +/- 9% (beer) and +/- 14% (soft drinks) for most of the trace elements. The satisfactory agreement meant that analyses of such liquids for trace elements can be carried out accurately with less expensive and widely available FAAS equipment.