Record Display for the EPA National Library Catalog

RECORD NUMBER: 694 OF 1687

OLS Field Name OLS Field Data
Main Title Evaluation and Comparison of the Cobalt Thiocyanate and Modified Dragendorf Reagent Test Methods for Nonionic Detergents.
Author Tabak, Henry H. ; Bloomhuff, Robert N. ; Bunch., Robert L. ;
CORP Author National Environmental Research Center, Cincinnati, Ohio. Advanced Waste Treatment Research Lab.
Year Published 1972
Stock Number PB-256 949
Additional Subjects Water analysis ; Detergents ; Surfactants ; Comparison ; Modification ; Industrial waste treatment ; Precipitation ; Solution ; Cobalt inorganic compounds ; Thiocyanates ; Potentiometric analysis ; Chemical analysis ; Water pollution ; Dragendorf reagent test methods ; Wickbold method ; Cobalt thiocyanate ; Water pollution detection
Holdings
Library Call Number Additional Info Location Last
Modified
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Status
NTIS  PB-256 949 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/23/1988
Collation 47p
Abstract
Studies were undertaken to evaluate a modified Dragendorf reagent test method for the determination of nonionic surfactants in influents and effluents of biological wastewater treatment plants and to compare its sensitivity with that of the cobalt thiocyanate method for nonionic detergents. The WICKBOLD method is based on the precipitation of the surfactant with a modified Dragendorf reagent (K2BiI4 + BaCl2 + acetic acid). The filtered precipitate is washed with acetic acid and dissolved in ammonium tartrate solution. The bismuth from the bismuth-surfactant complex in solution is then titrated potentiometrically at pH 4 - 5 with 0.0005 N pyrrolidine dithiocarbamate solution using a platinum and calomel electrode. The cobalt thiocyanate method involves the treatment of the detergent with ammonium cobalt thiocyanate solution, chloroform extraction of the surfactant-cobalt thiocyanate complex and the spectrophotometric analysis of the complex in chloroform at 318 nm. The three nonionic surfactants used in the studies were: (1) fatty alcohol ethoxylate with 30.7 ethylene oxide units, (2) fatty alcohol ethoxylate with 10.6 ethylene oxide units, and (3) nonyl phenol ethoxylate.