CELLULOSE TETPA - A CHELATING COLLECTOR DESIGNED FOR MULTIELEMENT PRECONCENTRATION IN FLOW SYSTEMS

A cellulose collector with immobilized triethylenetetraminepentaacetic acid (TETPA) groups has been developed for multielement preconcentration (e.g., Al, Be, Bi, Cd, Co, Cu, Fe(III), In, Mn, Ni, Pb, TI(III), U(VI), V(IV), Zn) using a low-pressure flow system. Analyte distribution coefficients K(d) of the order of 10(4)-10(5) ml/g (0.5 mol/I NaCl, pH 3-8) and fast exchange kinetics enable effective trace/matrix separations by means of small TETPA-filled (75 mg) columns even at high flow rates (contact time < 1 s). Accordingly, recovery rates ranging from 88 (Tl(III)) to 99.5% (Ni), relative standard deviations s(r) mostly between 1.5 and 4.0% (off-line determined by flame AAS) and blank levels (e.g., Cu, Fe, Zn) in the lower ng range (quantified by ETAAS) can be achieved. Metal-complexing dissolved organic substances (e.g. humic substances), however, considerably lower the recovery rates of some analytes (e.g., Cu, Fe, Ni). A series of water analyses (e.g., river, sea, bog water) prove the reliability of the developed flow-preconcentration system.