高效阴离子交换色谱-脉冲安培检测法测定烘焙咖啡豆及其掺假物中的糖类标记物

Determination of carbohydrate markers in roasted coffee beans and adulterated products by high performance anion exchange chromatography-pulse amperometric detection

中文关键词:  高效阴离子交换色谱脉冲安法  烘焙咖啡豆  掺假物  糖类标记物

英文关键词:high performance anion-exchange chromatography-pulse amperometric detection  roasted coffee beans  adulteration  carbohydrate markers

中文摘要:

      目的 建立高效阴离子交换色谱-脉冲安培检测法(high performance anion-exchange chromatography with pulsed ampero-metric detection, HPAEC-PAD)测定烘焙咖啡豆及其掺假物中糖类标记物甘露醇、阿拉伯糖、半乳糖、葡萄糖、木糖、甘露糖、果糖的分析方法。方法 样品经盐酸水解, 用氢氧化钠溶液调节至中性, 样品溶液经滤纸过滤; 滤液适当稀释, 并经0.45 μm滤膜过滤后直接进样检测; 选用DionexCarboPac PA1色谱柱分离, 氢氧化钠溶液和乙酸钠溶液作为淋洗液洗脱, 流速1.0 mL/min, 脉冲安培检测器测定。结果 该方法7种糖在50 min内实现完全分离, 分离度达到1.5以上, 甘露醇、阿拉伯糖、半乳糖、葡萄糖在0.5~30 mg/L浓度范围内, 木糖、甘露糖、果糖在1.0~30 mg/L浓度范围内具有良好的线性, 相关系数在0.9990和 0.9999之间; 方法准确度和精密度良好, 加标回收率在86.0%~101.0%之间, 相对标准偏差(relative standard deviation, RSD)均小于5.0%。结论 该方法线性范围广, 准确性和精密度良好, 操作简便, 结果满意, 能满足咖啡掺假研究的要求。

英文摘要:

      Objective To establish a method for the detection of mannitol, arabinose, galactose, glucose, xylose, mannose and fructose in roasted coffee beans and its adulterates by high performance anion-exchange chromatography (HPAEC) with pulsed ampero-metric detection (PAD). Methods The samples were hydrolyzed with hydrochloric acid, adjusted to neutral with sodium hydroxide solution, and filtered with filter papers. Then the samples were diluted and filtered through 0.45 μm membranes. The DionexCarboPac PA1 column was used and sodium hydroxide solution and sodium acetate solution were used as a mobile phase. The flow rate was 1 mL/min. The samples were detected by PAD. Results Seven kinds of carbohydrates were completely separated within 50 min. The chromatographic peak separations of 7 carbohydrates were greater than 1.5. The method had good linearity for mannitol, arabinose, galactose and glucose in the range of 0.5-30 mg/L, and for xylose, mannose and fructose in the range of 1.0-30 mg/L. The correlation coefficients were between 0.9990 and 0.9999, and the accuracy and precision were good. The recovery rates were 86.0%-101.0%, and the relative standard deviations (RSDs) were less than 5.0%. Conclusion The method has wide linear range, good accuracy and precision, and is easy to operate and satisfactory, which can meet the requirements of adulterated coffee research.