Premium
Microdetermination of anionic and nonionic surfactants with aid of cholinesterase
Author(s) -
Tsuji Kazuro,
Tanaka Hironori,
Konishi Kazuo
Publication year - 1975
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/bf02545086
Subject(s) - sodium dodecylbenzenesulfonate , chemistry , pulmonary surfactant , ether , sodium , hydrolysis , sodium diethyldithiocarbamate , chromatography , potentiometric titration , sodium dodecyl sulfate , inorganic chemistry , nuclear chemistry , organic chemistry , biochemistry , ion
The potentiometric method for the microdetermination of anionic and nonionic surface‐active agents was studied by using the phenomena that anionics inhibit the enzyme system, cholinesterase‐butyrylthiocholine iodide, and nonionics apparently weaken the inhibitory effect of anionics. A constant current is applied across two platinum plate electrodes immersed in the solution containing butyrylthiocholine iodine and surfactant. A cholinesterase solution is added to cause enzymatic hydrolysis of substrate and a change in the electrode potential due to formation of thiol automatically recorded vs time. A decrease in the initial velocity of the enzymatic hydrolysis caused by inhibitor corresponds to the concentration of anionic surfactant. In the case of determining nonionic surfactant, a fixed amount of sodium linear pentadecylbenzenesulfonate is added as inhibitor. The degree of suppression of inhibitory effect is a direct measure of the concentration of the nonionic surfactant. By this method, 5–25 ppm sodium linear dodecylbenzenesulfonate and sodium branched dodecylbenzenesulfonate; 5–100 ppm sodium dodecyl sulate; 1–10 ppm polyoxyethylene dodecyl ether; 5–30 ppm polyoxyethylene sorbitan dodecanoate, and 5–40 ppm polyoxyethylene octylphenyl ether could be determined.