Voltammetric determination of stability constants of lead complexes with vitamin C

Branica, Gina; Metikoš-Huković, Mirjana; Omanović, Dario (2006) Voltammetric determination of stability constants of lead complexes with vitamin C. Croatica Chemica Acta, 79 (1). pp. 77-83. ISSN 0011-1643

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Abstract

Interactions between lead and ascorbic acid were investigated by polarography and voltammetry. The following techniques were applied: sampled polarography, differential pulse anodic stripping voltammetry, and square-wave voltammetry. Measurements were performed in perchlorate aqueous solutions under physiological ionic strength (0.15 mol dm(-3)). Electrochemical reaction of the lead(II) ascorbate complex was studied in various electrolyte compositions to find the optimal measurement conditions for determination of the corresponding stability constants ([Pb2+] = 4 x 10(-7) mol dm(-3), pH = 5.5; total concentration of ascorbic acid between 10(-5) and 10(-1) mol dm(-3)). Determination of stability constants of labile lead(II) ascorbate complexes was based on the DeFord-Hume methodology, and they were calculated from the dependence of the shift of Pb-II peak potential on the free ascorbate ion concentration. The computed stability constants were: log beta(1) = 9.3 +/- 0.2 and log beta(2) = 18.0 +/- 0.1.

Item Type:	Article
Uncontrolled Keywords:	lead; L-ascorbic acid; voltammetry; stability constants; l-ascorbic-acid; aqueous-solution; coordination chemistry; fluoride complexes; metal-ions; polarography
Subjects:	NATURAL SCIENCES > Chemistry
Divisions:	Division for Marine and Enviromental Research
Projects:	Project title Project leader Project code Project type Novi materijali i katalizatori za održive tehnologije Mirjana Metikoš-Huković 0125011 MZOS Međudjelovanje i modeliranje prelaznih metala s bioligandima Jasmina Sabolović 0022017 MZOS Fizikalna i biogeo-kemija tragova metala u vodenim sustavima Ivanka Pižeta 0098121 MZOS
Depositing User:	Dario Omanović
Date Deposited:	29 Oct 2013 12:23
URI:	http://fulir.irb.hr/id/eprint/864

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