Departament de Química Analítica, Universitat de València, c/Dr. Moliner 50, 46100, Burjassot, Valencia, Spain.
Anal Bioanal Chem. 2018 Aug;410(20):5043-5057. doi: 10.1007/s00216-018-1161-0. Epub 2018 Jun 19.
Most reports in reversed-phase liquid chromatography (RPLC) with micellar mobile phases make use of the anionic sodium dodecyl sulfate. This surfactant masks efficiently the silanol groups that are the origin of the poor efficiencies and tailing peaks observed for basic compounds in conventional RPLC. However, it has the handicap of yielding excessive retention, which forces the addition of an organic solvent to reduce the retention times to practical values. Other surfactants, such as the non-ionic polyoxyethylene(23)lauryl ether (Brij-35), are rarely used. Brij-35 allows the separation of a large range of analytes in adequate retention times, without the need of adding an organic solvent to the mobile phase. However, this non-ionic surfactant shows irreversible adsorption on chromatographic columns and peak shape is poorer. Therefore, the search of non-ionic surfactants with similar properties to Brij-35, but showing reversible adsorption and better peak shape, can be of great interest. In this work, the adequacy of several non-ionic surfactants as modifiers in RPLC has been explored, being polyoxyethylene(10)tridecyl ether particularly attractive. The separation of different types of compounds was checked: sulfonamides (acidic), β-adrenoceptor antagonists and tricyclic antidepressants (basic with diverse polarity), and flavonoids (with and without hydroxyl groups on the aromatic rings). The chromatographic behaviors were examined in terms of retention and peak shape. The results were compared with those obtained with Brij-35.
反相液相色谱（RPLC）中与胶束流动相的大多数报告都利用阴离子十二烷基硫酸钠。这种表面活性剂有效地掩盖了硅醇基团，这些基团是在常规 RPLC 中观察到碱性化合物效率低下和拖尾峰的原因。然而，它有产生过度保留的缺点，这迫使添加有机溶剂以将保留时间降低到实际值。其他表面活性剂，如非离子聚氧乙烯（23）月桂醚（Brij-35），很少使用。Brij-35 允许在足够的保留时间内分离大量分析物，而无需向流动相中添加有机溶剂。然而，这种非离子表面活性剂在色谱柱上表现出不可逆吸附，并且峰形较差。因此，寻找具有类似于 Brij-35 的性质但表现出可逆吸附和更好的峰形的非离子表面活性剂可能非常有意义。在这项工作中，已经探索了几种非离子表面活性剂作为 RPLC 中的修饰剂的适宜性，其中聚氧乙烯（10）十三烷基醚特别有吸引力。检查了不同类型化合物的分离：磺胺类（酸性），β-肾上腺素受体拮抗剂和三环抗抑郁药（具有不同极性的碱性）和黄酮类（芳环上带有或不带有羟基）。根据保留和峰形检查了色谱行为。将结果与用 Brij-35 获得的结果进行了比较。
