Quantitation of metal complexes by reverse-pulse amperometry and molecular-exclusion chromatography

High-pressure, aqueous, size-exclusion chromatography of copper(II) complexes of polyaminocarboxylic acids, catechol, and fulvic acids using reverse-pulse amperometric detection

“…A flow rate of 0.5 mL/min which had a HETP of 0.1 mm/plate was selected for most of the subsequent separations for peak area measurements. This represents a tenfold improvement in efficiency since a HETP of approximately 1 mm/plate has been previously observed for the Sephadex gels (8,16). The linearity of the detector response in terms of peak height to the amount of EDTA after separation on the TSK column was determined using concentrations from 2.5 X 10"4 to 1.5 X 10"3 M with an injection volume of 20 mL.…”

“…We have previously reported on the use of Sephadex gels to separate and quantify metal complexes using a modified Hummel-Dreyer technique, which utilizes an eluent containing excess metal ions to prevent dissociation of labile complexes'during the separation process (8). Poly (aminocarboxylic acids), citric acid, and fulvic acids were studied using copper(II) in the eluent.…”

Selective detection of metal species in HPLC and FIA by means of pulsed amperometric detection (PAD)

“…determination of Fe(II)/Fe(III) [9][10][11] or trace metals bound to electroactive ligands [12][13][14][15][16][17]. The selectivity of the detection, however, is limited by interference of electroactive matrix components and also by irreversible reactions of species or reaction products at the working electrode (electrode fouling).…”