DETERMINATION OF NATAMYCIN CONTENT IN CHEESE USING ULTRA PERFORMANCE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY

摘要

Nalamycin is a fungistatic antibiotic that is used therapeutically only for a surface treatment and does not cause resistance of yeasts and fungi. It has a broad spectrum of activity for most yeasts and fungi that come into consideration in food. A methods based on the use of ultra-performance liquid chromatography tandem mass spectrometry (UPLC/ MS/ MS) and lime of flight mass spectrometry (UPLC/ TOF MS) interfaced with eleclrospray were devised for determination of nalamycin content in cheese samples. Sample preparation included, extraction offal and protein removal by congelation. In case of loiv concentrations of nalamycin, extract was concentrated by SPE. UPLC was performed on an Acquily UPLC BEH C18 (100mm x 2.1mm). UPLC/TOF data were acquired in TOF MS full scan mode. UPLC/MS/MS data acquisition was achieved using multiple reaction monitoring (MRM). The elaborated methods for determination of nalamycin in cheese were validated. Detection limits vary depending on the mass spectrometer. For UPLC/ TOF detection limit is 50 ng- kg"', for the the triple quadrupole 5 mugkg"1. The relative standard deviation (RSD) of the method was for the UPLC/TOF, 3%, and for UPLC/MS/MS, 5.3%. The described methods meet all the criteria of Decision 2002/657/EC and are easy to use in routine analyses.