超高效液相色谱法直接测定糖浆中低聚半乳糖质量分布

Direct determination of the mass profiling of galactooligosaccharidesin syrup by ultra high performance liquid phasechromatography

中文关键词:  低聚半乳糖  质量分布  蒸发光散射检测器  超高效液相色谱法

英文关键词:galactooligosaccharide  mass profiling  evaporative light scattering detector  ultra high performance liquid chromatography

中文摘要:

      目的 建立一种超高效液相色谱-蒸发光散射检测器联用测定糖浆中低聚半乳糖质量分布的方法。 方法 采用Agilent Poroshell 120 HILIC(3.0 mm×100 mm, 2.7 μm)色谱柱分离, 以乙腈-水梯度洗脱。通过调节进入蒸发光散射检测器(evaporative light scattering detector, ELSD)的流动相流速以及组成来校正不同聚合度聚半乳糖的响应一致性。以葡萄糖、乳糖、麦芽三糖、麦芽四糖和麦芽五糖为校正溶液来建立校正方法, 校正后以乳糖标准曲线来定量其他低聚半乳糖, 最终完成了在没有低聚半乳糖标准品的情况下对低聚半乳糖糖浆质量分布的测定。结果 样品中的乳糖与其他半乳二糖分离的同时不同聚合度的低聚半乳糖按聚合度增加分段出峰, 互不干扰。乳糖在0.25~5 mg/mL范围内线性良好, log(峰面积)-log(浓度)的线性拟合曲线, 相关系数r2为0.996。以麦芽四糖和麦芽五糖来验证方法准确性, 所得回收率分别为107%和110%。方法重现性良好, 以2 mg/mL乳糖为考察对象, 连续6针进样保留时间RSD<0.05%, 峰面积RSD<0.78%。结论 该方法可快速、准确用于低聚半乳糖糖浆中不同聚合度半乳糖的质量分布。

英文摘要:

      Objective To develop a method for mass profiling determination of galactooligosaccharides (GOS) in syrup by ultra high performance liquid chromatography coupled with evaporative light scattering detector (ELSD). Methods The sample was separated on the Agilent Poroshell 120 HILIC column (3.0 mm×100 mm, 2.7 μm) with ACN-water gradient elution. Reverse gradient and flow rate compensation were used to adjust the universal response of GOSs. The mixed solution of glucose, lactose, maltotriose, maltotetraose and maltopentaose was employed for calibration. Then the mass profiling determination of GOS was accomplished via the calibration curve of lactose without any GOS standards by the developed method. Results The lactose in syrup could be baseline-separated from other galactobiose, meanwhile, GOS with different DPs had no interference with each other. The linearity was good (r2=0.996) for lactose with log(area)-log(conc.) fitting in the range of 0.25~5 mg/mL. The accuracy was proved satisfied by obtaining recoveries of 107% and 110% for maltotetraose and maltopentaose separately. It was also showed that the developed method had ex- cellent precision with 0.05%RSD of retention time and 0.78%RSD of peak area for lactose with 6 consecutive injections at 2.0 mg/mL. Conclusion The proposed method is fast and accurate, which is suitable for mass profiling determination of GOS in syrup.