关键词: 乳与乳制品, 高效液相色谱法, 香兰素, 甲基香兰素, 乙基香兰素, 香豆素

Abstract: A reversed-phase high performance liquid chromatography (RP-HPLC) method for the simultaneous quantitative determination of vanillin, methyl vanillin, ethyl vanillin and coumarin in milk and dairy products has been established. Vanillin compounds from samples were extracted with acetonitrile, blown to dryness under nitrogen, and then cleaned up with n-hexane. The chromatographic separation was achieved using a mixture of 20 mmoL/L ammonium acetate (pH 5.6), acetonitrile and methanol as the mobile phase with gradient elution on a C18 column. The analysis was carried out using a UV detector at a wavelength of 267 nm and the analytes were quantified by an external standard method. Good linear relationships in the range of 0.05–5.00 μg/mL were observed for all analytes. The limit of quantification was 0.2 mg/kg and the limit of detection was 0.06 mg/kg for the four analytes in liquid milk, milk powder, yogurt, lactic acid fermented beverage, ice cream, and cheese. The recoveries for vanillin, methyl vanillin, ethyl vanillin and coumarin in these samples at spiked concentration levels of 0.2–2.0 mg/kg were 80.6%–110.0%, 80.1%–109.6%, 80.4%–109.5% and 80.1%–105.9%, with relative standard deviations of 1.87%–7.70%, 1.45%–9.80%, 1.66%–9.52% and 1.16%–9.52%, respectively. This method was rapid, accurate, repeatable and simple and could be applied to determine vanillin compounds in milk and dairy products.

Key words: milk and dairy products, high performance liquid chromatography, vanillin, methyl vanillin, ethyl vanillin; coumarin