Abdollah Tavassoli - Analytical of Chemistry, University of Mazandaran, Babolsar, Iran
Seyed Naser Azizi - Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, ‎Babolsar, Iran
Abdolraouf Samadi-Maybodi - Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran

Erythromycin is one of the typical macrolides, which is isolated by the Saccharopolyspora ‎erythraea. It has been listed in WHO essential medicine for improvement of the efficiency of ‎health system. In this study, magnetic iron nanoparticles were coated with cetyl as a non-polar ‎functional group and characterized by various techniques such as Infrared Spectroscopy, ‎thermal gravimetric analysis‎, scanning electron microscopy and vibrating sample ‎magnetometer. The as-prepared nanoparticles were used to extract erythromycin from the milk ‎samples. Separation was performed on a pentaflurophenyl column (۱۵۰*۲mm,۳μm) using a ‎mobile phase consisting ۷۰% acetonitrile and ۳۰% ammonium acetate (۱۰mM, pH۳.۵) with a ‎high performance liquid chromatography system coupled with tandem mass spectrometry.‎ The ‎separation was fast and completed in less than ۵ minutes, under the optimized condition. Stable ‎isotope of erythromycin was used as internal standard in the sample preparation and calibration ‎curve. It was found that relative recovery of the method was ۹۲.۶%. The proposed method was ‎convenient and quick preparation method was achieved using external magnetic field without ‎centrifugation and filtration.‎ The detection limit and coefficient of determination were ۲.۴ ‎μg/L and R۲ = ۰.۹۹۸۳, respectively. The intra- and inter-day precisions of the proposed method ‎in different levels of spiked sample were in the range of ۵.۶-۸.۵% and ۸.۴-۱۲.۵%, respectively.‎

Antibiotic, Erythromycin, Magnetic Fe۳O۴-C۱۶ nanoparticles, Tandem mass spectrometry, Milk