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Determination of Inorganic Arsenic Species by Electrochemical Hydride Generation Atomic Absorption Spectrometry with Selective Electrochemical Reduction
Author(s) -
Li Xun,
Wang ZhengHao
Publication year - 2007
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.200790058
Subject(s) - chemistry , arsenic , absorbance , hydride , atomic absorption spectroscopy , analytical chemistry (journal) , electrochemistry , detection limit , calibration curve , electrolyte , supporting electrolyte , standard addition , inorganic chemistry , metal , chromatography , electrode , physics , organic chemistry , quantum mechanics
A new direct procedure for the determination of inorganic arsenic species was developed by electrochemical hydride generation atomic absorption spectrometry (EcHG‐AAS) with selective electrochemical reduction. The determination of inorganic arsenic species is based on the fact that As(III) shows significantly higher absorbance at low electrolytic currents than As(V) in 0.3 mol·L −1 H 2 SO 4 . The electrolytic current used for the determination of As(III) without considerable interferences of As(V) was 0.4 A, whereas the current for the determination of As(III) and As(V) was 1.2 A. For equal concentrations of As(III) and As(V) in a sample, the interferences of As(V) during the As(III) determination were smaller than 5%. The absorbance for As(V) could be calculated by subtracting that for As(III) measured at 0.4 A from the total absorbance for As(III) and As(V) measured at 1.2 A, and then the concentration of As(V) can be obtained by its calibration curve at 1.2 A. The methodology developed provided the detection limits of 0.3 and 0.6 ng·mL −1 for As(III) and As(V), respectively. The relative standard deviations were of 3.5% for 20 ng·mL −1 As(III) and 3.2% for 20 ng·mL −1 As(V). The method was successfully applied to determination of soluble inorganic arsenic species in Chinese medicine.