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Adsorptive stripping voltammetric measurements of trace niobium levels following chelation with cupferron
Author(s) -
Wang Joseph,
Lu Jianmin,
Taha Ziad
Publication year - 1992
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.1140041011
Subject(s) - niobium , adsorptive stripping voltammetry , chemistry , detection limit , stripping (fiber) , hanging mercury drop electrode , vanadium , trace amounts , analytical chemistry (journal) , voltammetry , inorganic chemistry , electrode , chromatography , electrochemistry , materials science , medicine , alternative medicine , organic chemistry , composite material , pathology
Trace levels of niobium can be determined by adsorptive stripping voltammetry, with controlled interfacial accumulation of the niobium/cupferron complex onto the hanging mercury drop electrode. Optimal conditions (5 times; 10 −6 M cupferron in acetate buffer (pH 4.0), a preconcentration potential of −0.2 V, and differential pulse stripping) allow convenient quantitation of μg/L (ppb) concentrations. The detection limit is 83 ppt (10 minute preconcentration); the response is linear over the 0–20 ppb range: and the relative standard deviation (at the 5 ppb level) is 2.0%. Most cations do not interfere in the determination of niobium. Complexation with cupferron also allows analogous trace measurements of vanadium.