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 0.5 mg/kg. Samples were extracted by a simple salting-out procedure, using acetonitrile and sodium chloride; about 100 samples could be prepared and analyzed daily. Special care had to be taken to thoroughly homogenize samples and to avoid the use of contaminated labware. The method was validated by a procedure in compliance with EU Directive 2002/657. From the matrixes of ice cream and minced meat, recoveries of more than 95% with a relative standard deviation of about 3% were obtained by 3 different analysts (n = 54). Detection limits were in the low microg/kg range. The decision limit (CCalpha) was determined to be 0.55 mg/kg. Dairy and meat products, collected in The Netherlands, were analyzed (761 samples). In 1% of the meat samples, 2% of the ice cream and milkshake samples, and 24% of the whipped cream samples, the Dutch legislative limit was exceeded. Over 2000 injections could be performed on a single column without deterioration of the peak shapes or recoveries.
Dutch Food and Non-Food Authority/Inspectorate for Health Protection and Veterinary Public Health, AE Zutphen, The Netherlands. michel.van.bruijnsvoort@vwa.nl
Michel
M
van Bruijnsvoort
Joop
J
Rooselaar
Alfred G
AG
Stern
Klaas M
KM
Jonker
D000818:Animals; D002700:Chloramines / Q000032:analysis; D002853:Chromatography, Liquid; D003611:Dairy Products / Q000032:analysis; D004202:Disinfectants / Q000032:analysis*; D004350:Drug Residues / Q000032:analysis; D005504:Food Analysis; D007202:Indicators and Reagents; D008460:Meat / Q000032:analysis; D009426:Netherlands; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D012015:Reference Standards; D015203:Reproducibility of Results; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D014105:Tosyl Compounds / Q000032:analysis
D002700:Chloramines; D004202:Disinfectants; D007202:Indicators and Reagents; D000644:Quaternary Ammonium Compounds; D012997:Solvents; D014105:Tosyl Compounds; C016300:chloramine-T