Premium
Coulometric determination of organic acids
Author(s) -
Crisler Robert O.,
Conlon Ralph D.
Publication year - 1962
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02637227
Subject(s) - coulometry , chemistry , titration , platinum , anode , electrolyte , standard solution , methanol , cathode , supporting electrolyte , solvent , inorganic chemistry , electrode , chromatography , electrochemistry , organic chemistry , catalysis
A system has been devised for the coulometric titration of organic acids in a non‐aqueous medium. The solvent system is benzene‐methanol, 1蝘1, containing LiCl as the electrolyte. The acid is titrated by reducing hydrogen ion at a platinum cathode. The anode reaction involves the formation of AgCl on silver. The endpoint is detected by an antimony‐glass electrode pair and the derivative of the electrode output is used to effect automatic current shut‐off. Alternative reference electrodes are discussed. Usual sample size titrated is 0.01 meq but the method can be applied to both larger and smaller amounts. The method has been applied to the determination of acid value and free fatty acid in fatty materials. The advantages of the coulometric determination are: 1) No standard solutions are required. 2) The titration is conducted without analyst attention. 3) The technique is simple and rapid.