牛奶中三种糖醇类甜味剂的气相色谱测定及前处理方法研究

曹玉林; 束天锋; 刘艳玲; 薛秀恒; 梅林; 王志耕; 孙郭艳

doi:10.13386/j.issn1002-0306.2015.10.005

牛奶中三种糖醇类甜味剂的气相色谱测定及前处理方法研究

Study on pretreatment methods for the simultaneous determination of three kinds of sugar alcohols in milk by gas chromatography

摘要

摘要: 利用冷冻干燥处理与毛细管气相色谱外标法测定牛奶中的糖醇类甜味剂。牛奶用乙酸锌和氢氧化钡除去蛋白质后,经冷冻干燥,样品中的糖醇与吡啶-乙酸酐（1∶1,v/v）于90℃反应30min,生成的糖醇乙酰酯衍生物经HP-5毛细管柱色谱分离,氢火焰离子化检测器检测。结果表明:与旋转蒸发相比,冷冻干燥处理样品的回收率更高。在优化的色谱条件下,本方法在10⁹0μg/m L范围内线性关系良好（r=0.9974⁰.9999）,重复性好（RSD=1.37%².04%）,平均加标回收率在91.17%⁹2.06%之间。该方法简单、快速、灵敏,适用于牛奶中糖醇类甜味剂含量的测定。

Abstract: A novel method was developed for the determination of sugar alcohol contents in milk by gas chromato-graphy after freeze-drying, and the external standard method was used to determine. After removal of protein by zinc sulphate and barium hydroxide, the freeze-drying was used to dry samples. The sugar alcohols reacted with pyridine- acetic anhydride ( 1 ∶ 1, v / v) at 90 ℃ for 30 min. The sugar alcohol acetate derivatives were analyzed by gas chromatography with HP- 5 ( 30 m × 320μm × 0. 25μm) and with a flame ionization detector. The results showed that the recoveries of sugar alcohols treated by freeze-drying was higher than rotary evaporation. Under the optional chromatographic conditions, the calibration curve was linear in the range of 10⁹0μg/m L (r=0.9974⁰.9999) . The repeatability was reproducible (RSD=1.37%².04%) . The average recoveries were between 91.17% and 92.06%. This method was simple and fast so that it could be used to determine sugar alcohol contents in milk.