| A simple method based on three-phase hollow fiber liquid-phase microextraction (HF-LPME) combined with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of benzoic and sorbic acids in drinks.The optimum extraction conditions for the three-phase hollow fiber liquid phase microextraction were as the follows:the porous membrance of hollow fiber was full of 1-octanol,the pH values of the donor phase and the acceptor phase were 2.7 and 13.6,respectively.HF-LPME was accomplished at room temperature,the extraction time was 30 min and the stirring speed was 1 000 revolutions per minute (rpm).The UPLC-MS/MS method was performed with Waters ACQUITY UPLCTM BEH C18(50 mm×2.1 mm,1.7 μm)using methanol-10 mmol/L ammonium formate as mobile phase by a gradient elution,at a flow rate of 0.25 mL/min.The target compounds were detected under ESI in negative mode，then analyzed in multiple reaction monitoring(MRM) mode,and the external standard method was used for quantification.The results showed that there are good linearities in the range of 0.05-5.0 mg/L with correlation coefficients higher than 0.997.The limits of detection(LOD) of benzoic and sorbic acids were 0.005,0.01 mg/L and the limits of quantitation(LOQ) were 0.01,0.02 mg/L,respectivley.The recoveries (n=6)at spiked levels of 0.1,1.0,4.0 mg/L were in the range of 91%-103% with RSDs less than 6.0%.This method was successfully applied in the analysis of benzoic and sorbic acids in different kinds of drinks. |