Rodríguez-Gonzalo Encarnación, Domínguez-Álvarez Javier, Mateos-Vivas María, García-Gómez Diego, Carabias-Martínez Rita
Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Ciencias Químicas, University of Salamanca, Salamanca, Spain.
Electrophoresis. 2014 Jun;35(11):1677-84. doi: 10.1002/elps.201300550. Epub 2014 Mar 10.
In this work CE-ESI-MS is proposed for the identification and simultaneous quantification of several ribonucleotide 5'-monophosphates in infant formula (IF) samples. The target compounds were adenosine 5'-monophosphate, cytidine 5'-monophosphate, guanosine 5'-monophosphate, uridine 5'-monophosphate, and inosine 5'-monophosphate. To our knowledge, the application of CE for the determination of these bioactive compounds in IFs has not yet been described. Optimization of the composition of the electrophoretic separation buffer and -mainly- the injection medium was carried out with a view to obtaining the best sensitivity and separation efficiency for the CE-MS coupling. Different sample treatments were assayed and one based on centrifugal ultrafiltration proved to be the simplest and most compatible with CE separation of the analytes and their ionization by the electrospray source. The whole optimized method (centrifugal ultrafiltration treatment prior to CE-MS) was validated according to the 2002/657/EC decision, obtaining a reliable and robust CE-MS method to determine these compounds in IF samples, with LODs between 0.8 and 1.8 μg/g (S/N = 3) and recoveries in the 90-106% range.
在本研究中，提出了毛细管电泳-电喷雾电离质谱联用（CE-ESI-MS）技术用于鉴定和同时定量婴幼儿配方奶粉（IF）样品中的几种5'-单磷酸核糖核苷酸。目标化合物为5'-单磷酸腺苷、5'-单磷酸胞苷、5'-单磷酸鸟苷、5'-单磷酸尿苷和5'-单磷酸肌苷。据我们所知，尚未有关于毛细管电泳用于测定IF中这些生物活性化合物的报道。为了实现CE-MS联用的最佳灵敏度和分离效率，对电泳分离缓冲液的组成，主要是进样介质进行了优化。对不同的样品处理方法进行了试验，结果表明基于离心超滤的方法是最简单的，并且与分析物的CE分离及其通过电喷雾源的电离最兼容。根据2002/657/EC决议对整个优化方法（CE-MS之前进行离心超滤处理）进行了验证，得到了一种可靠且稳健的CE-MS方法来测定IF样品中的这些化合物，检测限在0.8至1.8 μg/g之间（S/N = 3），回收率在90-106%范围内。
