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Cathodic Adsorptive Voltammetry of the Gallium‐Alizarin Red S Complex at a Carbon Paste Electrode
Author(s) -
Li YiHeng,
Zhao QiaoLing,
Huang Meihua
Publication year - 2005
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200203096
Subject(s) - gallium , detection limit , horizontal scan rate , chemistry , carbon paste electrode , electrode , alizarin red , adsorption , buffer solution , analytical chemistry (journal) , voltammetry , cyclic voltammetry , nuclear chemistry , inorganic chemistry , electrochemistry , chromatography , organic chemistry , medicine , staining , pathology
The adsorptive voltammetric behavior of the gallium‐alizarin red S (ARS) complex in NH 4 OAc‐HCl buffer at a carbon paste electrode(CPE) was investigated. The results showed that the complex can be adsorbed on the surface of the CPE, yielding one reduction peak at −0.52 V(vs. SCE), corresponding to the irreversible reduction of the ligand, ARS, bonded in the complex. The optimal experimental conditions include the use of 0.10 mol L −1 ammonium acetate buffer(pH 4.5), 1.0×10 −5 mol L −1 ARS, an accumulation potential of −0.05 V, an accumulation time of 180 s ,a rest time of 10 s, a scan rate of 200 mV s −1 and a second‐order derivative linear scan mode. The peak current is proportional to the concentration of gallium(III) over the range 0.02–6.0 μg L −1 , with the detection limit of 0.01 μg L −1 for an accumulation time of 180 s. The method was applied to the determination of gallium in food samples with satisfactory results.