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Indirect Determination of Ascorbic Acid with Ammonium Sulfate and Ethanol by Extraction and Flotation of Copper
Author(s) -
Shen YiYang,
Li QuanMin,
Wei Wei
Publication year - 2001
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200100030
Subject(s) - ascorbic acid , chemistry , extraction (chemistry) , copper , ammonium sulfate , yield (engineering) , ethanol , inorganic chemistry , thiocyanate , copper extraction techniques , ammonium thiocyanate , chromatography , sulfate , nuclear chemistry , organic chemistry , metallurgy , food science , materials science
A new method of indirect determination of ascorbic acid with ammonium sulfate and ethanol by extraction and flotation of copper in the presence of thiocyanate has been studied in this paper. The study shows that a small amount of Cu(II) is reduced to Cu(I) by ascorbic acid, then Cu(I) precipitates with SCN − . In the course of phase separation of ethanol from water, the precipitated CuSCN is extracted and stays in the interface of ethanol and water. A good linear relationship is observed between the extraction yield of Cu(II) and the amount of ascorbic acid. The detection limit for ascorbic acid is 1 10 −5 M. Every parameter has been optimized and the reaction mechanism has been studied. The method is simple, rapid (5 min) and suffers from few interferences of common anions and cations. It has been successfully applied for the determination of ascorbic acid in pharmaceuticals and fruits.