梯度洗脱优化-离子色谱-脉冲安培法分析婴幼儿配方乳粉中的糖和糖醇

建立了梯度洗脱优化-离子色谱-脉冲安培检测技术分析婴幼儿配方乳粉中麦芽糖醇、半乳糖、葡萄糖、蔗糖、果糖、乳糖6种与代谢疾病紧密相关的糖和糖醇的方法。该方法对样品的前处理、色谱柱的选择、淋洗液的梯度等色谱条件进行了优化,重点研究了淋洗液梯度对各组分分离效果的影响。将梯度洗脱程序分解为弱保留组分分离、乳糖分离、基质消除、系统平衡4个子程序,并分别对其进行了条件优化,实现了6种组分的完全分离,并有效解决了弱保留组分色谱峰易重叠、乳糖色谱峰易拖尾等现象。6种组分的线性范围为0.5~100 mg/L,相关系数(r)0.99,方法的检出限(S/N=3)为0.06~0.40 mg/L。该方法具有分离度好、灵敏度高等优点,可满足例行分析的要求,同时也为淋洗液的梯度优化提供了可借鉴的方法。

Determination of carbohydrates and sugar alcohol in infant formula by ion chromatography with pulsed amperometric detection and an optimized gradient elution

A method was developed for the determination of carbohydrates and sugar alcohol related closely to metabolic diseases in infant formula, including maltitol, galactose, glucose, sucrose, fructose and lactose, by ion chromatography (IC) with pulsed amperometric detection and an optimized gradient elution. The developed method included the systematic optimizations of sample pre-treatment, column selection and gradient elution. And more attention has been paid to optimizing the gradient elution program. According to the chromatographic behavior of the targets, the total gradient elution was divided into four subprograms, including separation of the analytes with weaker retentions, separation of lactose, matrix elimination and system equilibrium, and each part was also optimized in detail. By the optimized gradient elution, both negative chromatographic phenomena of overlapping between analytes with weak retentions and tailing for lactose were eliminated well, and all of the analytes were separated completely. Both maltitol and galactose were fitted well with quadratic curve, and the others were fitted well with linear equation, with the correlation coefficients (r) greater than 0.99, in the concentration range of 0.5-100 mg/L, with the limits of detection (LODs) (S/N=3) of 0.06-0.40 mg/L. The developed method offered a helpful method for gradient elution optimization, and it had been used for the determination of the real samples. It was proved to be feasible for routine analysis.