毛细管区带电泳-间接紫外检测法快速测定食品中乳糖、蔗糖、葡萄糖和果糖

Rapid determination of lactose,sucrose,glucose and fructose in foods by capillary zone electrophoresis with indirect ultraviolet detection

建立了毛细管区带电泳-间接紫外检测快速测定食品中乳糖、蔗糖、葡萄糖和果糖的方法。以水或5 mmol/L醋酸为样品提取液,未涂层熔融石英毛细管（30.2 cm（有效长度20 cm）×50μm）为分离柱,4 mmol/L山梨酸钾＋10 m m o l/L磷酸钠＋30 m m o l/L Na OH（p H 12.56）＋0.5 m m o l/L十六烷基三甲基溴化铵（CTAB）为分离缓冲液,在-8 k V下分离,于254 nm波长下检测,10 min内实现了食品中上述4种糖的同时分离与测定。乳糖、蔗糖、葡萄糖和果糖的检出限（S/N=3）分别为50、75、25和25 mg/L,定量限（S/N=10）分别为150、225、75和75 mg/L,回收率在87.0%～107.0%之间,相对标准偏差在1.2%～4.7%之间。整个实验过程未使用有机溶剂。用该法测定了9种食品样品及1个质控样品,结果表明该法简单、快速、准确,适用于食品中乳糖、蔗糖、葡萄糖和果糖的日常测定。

A new and rapid method for the simultaneous determination of lactose, sucrose, glucose and fructose by capillary zone electrophoresis （ CZE ） with indirect ultraviolet detection was developed. The separation was completed with an uncoated fused-silica capillary with 30.2 cm of total length （ effective length of 20 cm） ×50 μm. The separation buffer consisted of 4 mmol/L potassium sorbate, 10 mmol/L sodium phosphate, 30 mmol/L NaOH （pH 12.56） and 0. 5 mmol/L hexadecytrimethylammonium bromide （CTAB）. The separation was performed at a voltage of -8 kV with the ultraviolet detection at 254 nm. The analysis of the four carbohydrates was completed within l0 min. The limits of detection （S/N=3） for lactose, sucrose, glucose and fructose were 50, 75, 25 and 25 mg/L, and the limits of quantification （S/N= 10） were ]50, 225, 75 and 75 mg/L, respectively. The average recoveries for the four carbohydrates were in the range of 87.0%-107.0% with the relative standard deviations of 1. 2% -4.7%. No organic solvent was consumed throughout the whole process of the analysis. The method was used for the analysis of nine food samples and a quality control sample. The results demonstrated that the method is simple, rapid, accurate, and suitable for the routine analysis of the four carbohy- drates in food samples.