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The Study of Indirect Determination of Tiopronin by Extraction Flotation Copper(II) with an Ammonium Sulfate‐Water‐n‐Propyl Alcohol System
Author(s) -
Zhang YuPing,
Li QuanMin,
Zhao XiaoHong,
Liu GuoGuang
Publication year - 2007
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.200700106
Subject(s) - tiopronin , chemistry , alcohol , yield (engineering) , emulsion , copper , extraction (chemistry) , ammonium sulfate , chromatography , detection limit , ammonium , organic chemistry , metallurgy , medicine , materials science , pharmacology
A novel method for indirect determination of tiopronin by extraction flotation of copper(II) with an ammonium sulfate‐water‐n‐propyl alcohol system was developed. The effects of different parameters, such as acidity, the amount of NH 4 SCN and various salts on the flotation yield of Cu(II), have been studied to optimize the experimental conditions. Under the optimum conditions, Cu(II) is reduced to Cu(I) by tiopronin, and the resulting Cu(I) can react with SCN − to form a white emulsion precipitate CuSCN. In the presence of (NH 4 ) 2 SO 4 , the mixture consisting of n‐propyl alcohol and water can be separated into an n‐propyl alcohol phase and a water phase. In the process of phase separation of n‐propyl alcohol from water, the precipitated CuSCN is extracted and stays in the interface of n‐propyl alcohol and water. The amount of tiopronin can be determined by measuring the flotation yield of Cu(II). The detection limit is 0.32 mg L −1 and the linear range is maintained in the range of 0.40±13.0 mg L −1 with a correlation coefficient of 0.9991. This proposed method has been successfully applied to the determination of tiopronin in tablets, urine and human plasma with satisfactory results.