Determination Of Nitrofuran Metabolites Residues In Bee Pollow And Propolis

The acquisition of bee pollen and propolis requires bee saliva processing. If nitrofuran antibiotics were used in bees feeding process, naturally, their residues will be found in raw materials. Since 2008, the positive detection has been found bee pollen export from China by different contries, such as chloramphenicoi, nitrofuran metabolites, oxytetracycline and tetracycline. There are no antibiotics test indicators of bee pollen and propolis in current national standards.And no relative study on detection method of nitrofuan metabolites in bee pollen and propolis has been reported. To ensure the food safety of bee pollen and propolis, and to meet the requirements of maximum residual execution limit (MRPL) 1.0 μg/kg of China, Europe and the United States, Japan and South Korea’s, it is very necessary to establish determination method of the veterinary drug residue nitrofurans in bee pollen and propolis.This paper, according to the complex features of bee pollen and propolis samples matrix, introduces the optimization on the basis of GB/T 21167-2007 Determination of nitrofuran metabolites residues in royal jelly-LC-MS/MS method. In pretreatment process, concentration and volume of acid solution, hydrolysis time, type of solid phase extraction column, extraction solvent and extraction method were mainly optimized, which established the ultimate pretreatment method. Concretely, samples were acidified with 8 mL 1% perchloric acid for 1 min and purified through HLB solid phase extraction columns. The collected sample solutions were derivatized at 37℃ for 16h with o-nitrobenzaldenhyde. After adjusting pH of the derivative to 7.0±1.0, the nitrofuran metabolites were extracted by ethyl acetate and analyzed by mass spectrometry. Based on the pretreatment, this text establishes the detection method of four nitrofuran metabolites(AOZ、AMOZ、AHD、SEM) in bee pollen and propolis by high performance liquid chromatography tandem mass spectrometry.The detection limit and quantitation limit of the method are 0.5 μg/kg and 1.0 μg/kg, respectively. The linearity of the method is good from 0.5 ng/mL to 20 ng/mL (r>0.99) The recoveries are 83.2% to 109.7% at three spiked levels of 1.0、2.0、5.0 μg/kg, and the relative standard deviation (RSD) is less than 10% for intra-day and under 15% for inter-day. An application test was performed,28 kinds of bee pollen and proplis matrix were spiked with four kinds of nitrofuran metabolites (AOZ、AMOZ、AHD、SEM) at the same level of 2.0 μg/kg. In three parallel samples of each matrix, the recoveries were greater than 70%, RSD less than 10.0%. The method is selective with strong anti interference, suitable for determination and confirmation of nitrofuran metabolites residues in bee pollen and propolis, and also able to meet the daily needs of detection.