OPTIMIZATION OF FLOW-INJECTION ONLINE MICROCOLUMN PRECONCENTRATION OFULTRATRACE ELEMENTS IN ENVIRONMENTAL-SAMPLES PRIOR TO THEIR SPECTROCHEMICAL DETERMINATION

The preconcentration of some elements such as Cd Co, Ni, and V(IV) was modeled in the presence of complexing agents such as citrate and oxal ate at high Ca, Mg, and sulfate concentrations on iminodiacetic acid/e thyl cellulose (IDAEC), a chelating cellulose. The effect of the speci es present in the solution was studied after construction of the speci es distribution curves using critical, estimated, and measured stabili ty constants. The stability constants of the IDAEC chelates were deter mined potentiometrically. The constants were calculated or estimated u sing computer programs. The diagrams calculated in homogeneous media w ere used for optimization of the flow injection on-line preconcentrati on for analysis of ultratrace metals in the highly mineralized water ' 'Hunyadi.'' (C) 1996 Academic Press, Inc.