[Determination of chloramphenicol in propolis and propolis-derived dietary supplements by high performance liquid chromatography-tandem mass spectrometry]

A method for determining chloramphenicol (CAP) in both propolis and propolis-derived dietary supplements was developed by utilizing high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The flavones in the samples were removed with a lead acetate solution and ammonia, and the fat-soluble interferences, such as beewax and vegetable oils, were removed with n-hexane after the sample dissolved in ethanol. Tert-butyl methyl ether was used as the back-extraction solvent to reduce co-extracting compounds, such as polyethylene glycol 400 (PEG 400) and glycerol, which are common adjuvants of dietary supplements, and some polar interferences. CAP was detected by HPLC-MS/MS and quantified by the internal standard method. The calibration curve showed a good linearity in the range of 0.20-50.0 μg/L. The limits of detection and the limits of quantification were 0.03 and 0.1 μg/kg, respectively. The recoveries in four different matrices at three spiked levels were in the 86.0%-114.4% range with the relative standard deviations from 0.3% to 4.9%. With the advantages of excellent universality, ease of operation, high sensitivity, and strong anti-interference capability, the proposed method was suitable for the determination of CAP in both propolis and propolis-derived dietary supplements.