亲水/离子交换混合模式色谱法快速检测婴幼儿食品和乳品中核苷酸含量

Rapid determination of nucleotides content in infant formula and dairy product by mixed-mode hydrophilic interaction/ion exchange chromatography

中文关键词:  婴幼儿配方食品  乳制品  亲水/离子交换混合模式色谱  核苷酸

英文关键词:infant formula  dairy product  hydrophilic interaction/ion exchange chromatography  nucleotide

中文摘要:

      目的 建立亲水/离子交换混合模式色谱-紫外检测法(hydrophilic interaction/ion exchange chromatography-ultraviolet detection, HILIC/IEC-UV)快速测定婴幼儿食品和乳制品中5种核苷酸(胞嘧啶核苷酸、腺嘌呤核苷酸、尿嘧啶核苷酸、鸟嘌呤核苷酸和次黄嘌呤核苷酸)含量的分析方法。方法 采用两性离子亲水作用色谱柱(Alphasil S-Xion), 以5 mmol/L磷酸二氢钾水溶液(磷酸调pH 3.0)-乙腈(70:30, V:V)为流动相, 对婴幼儿食品和乳品中的核苷酸进行检测。结果 该方法在10 min内实现了5种核苷酸的高效分离, 5种核苷酸在2~50 μg/mL线性范围内线性关系良好, 检出限(limits of detection, LODs)为0.19~0.66 mg/kg, 定量限(limits of quantification, LOQs)为0.62~2.19 mg/kg。在50、100、200 mg/kg的加标水平, 5种核苷酸的日内回收率为96.6%~108.9%, 相对标准偏差(relative standard deviations, RSDs)为1.5%~6.3%, 日间回收率为101.0%~108.0%, RSDs为2.4%~7.3%。结论 与传统的反相离子对色谱法相比, 本方法具有显著优势: 有效降低了样品基质干扰, 缩短了分析时间, 提高了检测效率, 特别是改善了胞嘧啶核苷酸的定量准确性。该方法快速、准确、抗干扰, 为婴幼儿食品和乳制品中核苷酸的高效分析提供了技术支持。

英文摘要:

      Objective To establish a rapid method for the determination of 5 kinds of nucleotides (cytidine-5’-monophosphate, adenosine-5’-monophosphate, uridine-5’-monophosphate, guanosine-5’-monophosphate and inosine-5’-monophosphate) in infant formulas and dairy products is developed based on mixed-mode hydrophilic interaction/ion exchange chromatography-ultraviolet detection (HILIC/IEX-UV). Methods A zwitterionic hydrophilic interaction chromatography column (Alphasil S-Xion) was used, with mobile phase consisting of 5 mmol/L KH2PO4 (pH adjusted to 3.0 with H3PO4)-acetonitrile (70:30, V:V) to detect nucleotides in infant foods and dairy products. Results The five nucleotides were baseline separated within 10 min, demonstrating efficient chromatographic performance. They exhibited good linearity within the range of 2–50 μg/mL, with limits of detection (LODs) between 0.19 and 0.66 mg/kg, and limits of quantification (LOQs) ranging from 0.62 to 2.19 mg/kg. At spiked levels of 50, 100 and 200 mg/kg, the intraday recoveries ranged from 96.6% to 108.9%, with relative standard deviations (RSDs) of 1.5%–6.3%, while the interday recoveries were between 101.0% and 108.0%, with RSDs of 2.4%–7.3%. Conclusions Compared with the traditional reversed-phase ion-pair chromatography, this method has significant advantages: Effectively reducing the matrix interference, shortening the analysis time, improving the detection efficiency, and especially improving the quantitative accuracy of cytidine-5’-monophosphate. The proposed method is rapid, accurate, and anti-interference, which provides technical support for the efficient analysis of nucleotides in infant formulas and dairy products.