采用超声辅助分散液相微萃取技术结合高效液相色谱法测定蜂蜜中的咖啡因.将样品用水溶解配制成100 g·L-1样品溶液,取7.5 mL样品溶液,加入三氯甲烷120 μL和甲醇1.5 mL,混匀后超声5 min,离心后吸取5 μL沉积相,在WondasilTM C18色谱柱上分离,以甲醇(1+1)溶液为流动相进行洗脱,紫外检测波长为274 nm.咖啡因的线性范围为10.0~500 μg·L-1,检出限(3S/N)为9 μg·L-1.测定值的相对标准偏差为2.7%~4.1%,加标回收率在96.6%~104%之间.

A method of HPLC combined with ultrasound-assisted dispersive liquid-liquid microextraction was used for the determination of caffeine in honey.The honey sample was dissolved in water to a mass concentration of 500 g·L-1.7.5 mL of the solution was mixed with 150 μL of chloroform and 1.5 mL of methanol by ultrasound for 5 min.The mixture was centrifuged.5 μL of the sedimentary phase was separated on a WondasilTM C18 column using methanol (1+1) solution as the mobile phase for elution.UV detection was made at the wavelength of 274 nm.The linearity range of caffeine was 10.0-500 μg·L-1 with detection limit (3S/N) of 9 μg·L-1.The recovery rates measured by standard addition method ranged from 96.6% to 104%,and the RSD ranged from 2.7% to 4.1%.