Determination of residues of quaternary ammonium disinfectants in food products by liquid chromatography-tandem mass spectrometry.

A liquid chromatography-tandem mass spectrometry method has been developed for the determination of residues of alkylbenzyldimethylammonium, didecyldimethylammonium, didodecyldimethylammonium, and benzyldodecylhydroxyethylammonium compounds in various food matrixes. These quaternary ammonium compounds (QAs) are used in the food industry as disinfectants. According to the Dutch Food Law, the total mass (expressed as cetyltrimethylammonium chloride) of QAs in food products shall not exceed the legislative limit of 0.

Determination of methyldibromoglutaronitrile in cosmetic products by high performance liquid chromatography with electrochemical detection.

Synopsis A method for the determination of methyldibromoglutaronitrile in cosmetic products is described. Reversed phase high performance liquid chromatography and reductive electrochemical detection is employed to provide for improved selectivity and detectability compared to alternative methods. The method detects 0.

High pressure liquid chromatographic determination of thioglycolic acid in cold wave fluids and depilating creams.

Synopsis A high pressure liquid chromatographic method is described for the determination of thioglycolic acid in hair waving fluids and depilatories. Prior to chromatography the acid is converted into a yellow-coloured nitrobenzooxadioazole (NBD) derivative to permit HPLC detection at 464 nm. Optimum derivatization conditions could be obtained when 0.