超高效液相色谱-紫外检测法测定婴幼儿配方乳粉中的核苷酸含量

Determination of Nucleotides in Infant Formula by Ultra-high Performance Liquid Chromatography

采用磺酸甜菜碱型两性离子亲水相互作用色谱法,建立婴幼儿配方乳粉中5种核苷酸(5’-胞嘧啶核苷酸、5’-尿嘧啶核苷酸、5’-腺嘌呤核苷酸、5’-次黄嘌呤核苷酸、5’-鸟嘌呤核苷酸)的测定方法。使用二维固相萃取模式,弱阴离子交换和强阳离子交换,对样品中的核苷酸进行提取,紫外检测器采集数据;用0.001%甲酸-乙腈溶液和pH 5的10 mmol/L磷酸二氢钠溶液作为流动相,等度洗脱。5种核苷酸在其线性范围内线性关系良好,定量限在0.10~0.15 mg/100 g范围内,方法回收率均在95%以上,精密度在10%以内。该方法快速、灵敏、准确,适合各类婴幼儿配方乳粉中核苷酸的测定。

A method for the quantitation of nucleotides(cytidine 5’-monophosphate,uridine 5’-monophosphate,adenosine 5’-monophosphate,inosine 5’-monophosphate,and guanosine 5’-monophosphate)in infant formula was developed by sulfoalkyl betaine-based zwitterionic hydrophilic interaction liquid chromatography.The nucleotides in samples were extracted by two-dimensional solid-phase extraction with weak anion exchange and strong cation exchange,data acquisition was achieved using a UV detector.Chromatographic separation was performed by isocratic elution with a mobile phase consisting of 0.001%formic acid-acetonitrile and 10 mmol/L sodium dihydrogen phosphate solution at pH 5.Under the optimized conditions,good linearity was observed for these nucleotides,with a limit of quantification in the range of 0.10 to 0.15 mg/100 g.The method recovery was above 95%and the precision(expressed as relative standard deviation,RSD)was within 10%.This method was fast,sensitive and accurate and could be applied for the determination of nucleotides in infant formula samples.