An Improved Method of Determining Concentration of Quaternary Ammonium Compounds in Water Solutions and in Milk

Abstract

abstract Methods of determining concentration of quaternary ammonium compounds (QACs) in water solution and in milk have been reviewed briefly by Miller and Elliker, who also reported a new, rapid test for QAC in milk based on reaction of QAC with eosin to form a red precipitate and subsequent titration to a colorless endpoint with a standard solution of anionic surf ace active agent (2). The rapid test has proven satisfactory for routine detection of QAC in milk, but the extraction method used does not yield total recoveries of QAC. Consequently a series of known concentrations of QAC in milk must be set up as standards and tested with the unknown sample for accurate interpretation of results with the method. A study therefore was undertaken to improve methods of extraction and titration of QAC in milk. The results obtained in this study also have been applied in developing a new method of determination of QAC in water solutions.