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Determination of Cr(VI) in the Presence of Complexing Agents and Humic Substances by Catalytic Stripping Voltammetry
Author(s) -
Grabarczyk Malgorzata,
Kaczmarek Lukasz,
Korolczuk Mieczyslaw
Publication year - 2007
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.200603838
Subject(s) - chemistry , chromium , adsorptive stripping voltammetry , certified reference materials , chelation , metal , voltammetry , humic acid , stripping (fiber) , inorganic chemistry , nuclear chemistry , chromatography , detection limit , electrochemistry , organic chemistry , electrode , fertilizer , electrical engineering , engineering
The voltammetric method of Cr(VI) determination in a flow system is proposed. Determinations can be carried out in the simultaneous presence of an excess of Cr(III), complexing agents, humic substances and surfactants. The method is based on the combination of a selective accumulation of the product of Cr(VI) reduction to the metallic state and a very sensitive voltammetric method of chromium determination in the presence of DTPA and nitrates. The calibration graph is linear from 1×10 −9 to 5×10 −8 mol L −1 for accumulation time of 30 s. The relative standard deviation is 5.2% ( n =5) for Cr(VI) concentration 1×10 −8 mol L −1 . The influence of humic and fulvic acids, complexing agents and surfactants on Cr(VI) and the interfering Cr(III) signal is presented. The method was applied to Cr(VI) determination in certified reference material, soil sample, natural water sample and EDTA extracts from soil certified reference material.