A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) was established for the determination of chloramphenicol

thiamphenicol and florfenicol in propolis and propolis derived dietary supplements including tablet

hard capsule and soft capsule.The samples were dissolved and dispersed with 0.1 mol/L hydrochloric acid solution

blended well with a vortex mixer

followed by ultrasonical extraction and purification with an HLB solid phase extraction column(SPE) tandemly connected with a NH2-SPE column.The extract was separated on an Waters ACQUITY UPLC-BEH C18 column(2.1 mm×100 mm，1.7 μm) by gradient elution using a mobile phase consisting of 0.1% formic acid and acetonitrile.The analytes were analyzed by HPLC-MS/MS with electrospray ionization(ESI) source in negative ion mode

and quantified by external standard method.Under the optimal conditions

there were good linear relationships for 3 analytes in the concentration range of 0.10-20.0 μg/L with correlation coefficients(r2) larger than 0.999.The limits of detection(LOD) and limits of quantitation(LOQ) for three targets in propolis

propolis tablet and propolis soft capsule were in the ranges of 0.037-0.083 μg/kg and 0.12-0.28 μg/kg

while the LODs and LOQs for those in propolis hard capsule were 0.39-0.47 μg/kg and 1.28-1.57 μg/kg

respectively.The recoveries at spiked levels of 2.5

5.0

10.0 μg/kg were between 66.6% and 120%

with relative standard deviations(RSD) of 0.80%-11%.This method was applied to the detection on 45 actual samples collected in laboratory.The samples of propolis derived dietary supplements were detected positive for chloramphenicol and florfenicol

among which the positive detection rate for chloramphenicol was 22.22%

and the maximum residue was 14.32 μg/kg

while the positive detection rate for florfenicol was 17.78%

and the maximum residue was 21.62 μg/kg.With the characteristics of simplicity

high sensitivity and good reproducibility

the method could meet the requirements for determination of chloramphenicol

thiamphenicol and florfenicol residues in propolis and propolis-derived dietary supplements.