ISSN:
1436-5073
Keywords:
cationic surfactant determination
;
formation of ternary ion associate
;
divalent anionic dyestuffs-quinidine associates
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract A sensitive and selective method is described for the determination of cationic surfactants, such as benzethonium, benzalkonium, cetylpyridinium and trimethylstearylammonium, based on the formation and extraction of ternary ion associates with an acid dye (bromophenol blue or bromochlorophenol blue) and quinidine. Quinidine reacts with divalent anionic dyestuffs to form a bulky 1∶1 complex anion, which is extractable into 1,2-dichloroethane as ternary ion associates with cationic surfactants in nearly neutral media. The ternary ion associate gives a blue product. Linearity of the calibration curve is improved and the extractability of the cationic surfactants is enhanced in the presence of quinidine. In addition, many other amines do not interfere with the determination. The blue ion associates can be used for the selective and sensitive spectrophotometric determination of cationic surfactants.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01242698
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