Determination Of Quinolone Residues In Bee Pollen

Bees collect flower pollen grains from the plants,add the nectar and the special gland secretions into the collection,and change the mixture into a kind of irregular oval shaped particle.This is bee pollen.If quinolone antibiotics were used in bees feeding process to prevent illness,naturally,their residues will be found in raw materials such as bee pollen.In recent years,there have been positive detections in bee pollen exported from China by different countries,such as chloramphenicol,quinolone residues,nitrofuran metabolites,oxytetracycline and tetracycline.But currently no national standard contains the antibiotics testing indicator for bee pollen.And even though there are only quality testing rules for bee pollen intermationally,the detection method of quinolone antibiotics residues in bee pollen was also rarely reported.For the food safety of bee pollen,it is quite necessary to establish a method for detection of quinolone residues in bee pollen.Basing on the complex features of bee pollen samples matrix,it’s very critical to establish a rapid and effective pretreatment method in the determination of quinolones in bee pollen.This study was established using solvent method to eliminate the matrix interference in bee pollen,and combined with solid phase extraction purification.In the pretreatment process,bee pollen samples were extracted with 15 mL 2.0%perchloric acid solution,PH value of the solution was adjusted to 6.0,the solution was purified through HLB solid phase extraction columns,and finally quinolone residues were analyzed by mass spectrometry.On the basis of sample pretreatment,a new method was established for the simultaneous determination of 18 kinds of quinolone residues in bee pollen by high performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS).The limit of detection(LOD)and the limit of quantitation(LOQ)of the method would be 5.0 μg/kg and 10.0 μg/kg,respectively.The calibration curve showed good linearity in the range of 1.0～50.0 μg/L with good precision and accuracy(R2>0.99).The average recoveries were 70.0%to 108.1%and the relative standard deviation(RSD)is between 10.0%to15.0%.In the detection of bee pollens,ciprofloxacin and norfloxacin were detected in some samples(e.g.Camellia pollen,Rape pollen,Chrysanthemum pollen).The range of detection results was between 10.2～69.7 μg/kg.The method has been demonstrated to be with strong anti-interference,and highly suitable for determination and confirmation of quinolone residues in bee pollen.It is able to meet the daily needs of detection.