1 3 DOI 10.1007/s10337-016-3156-3 Chromatographia (2016) 79:1333–1341 ORIGINAL Novel Monolithic Stationary Phase with Surface‑Grafted Triphenyl Selector for Reversed‑Phase Capillary Electrochromatography Tahar Mekhalif 1,2 · Seydina Ibrahima Kebe 1 · Mohamed Guerrouache 1 · Noureddine Belattar 2 · Marie Claude Millot 1 · Benjamin Carbonnier 1 Received: 21 March 2016 / Revised: 26 July 2016 / Accepted: 28 July 2016 / Published online: 9 August 2016 © Springer-Verlag Berlin Heidelberg 2016 Keywords Capillary electrochromatography · Phenyl-like monolith · Reversed-phase · Trityl Introduction It is well accepted that one of the major advantages of polymer-based monolithic stationary phases is the ease and flexibility of their synthesis owing to the wide range of available monomers incorporating side chains of inter- est as chromatographic selectors [1–4]. This is particularly true regarding the development of miniaturized chromato- graphic columns, where the polymeric monolith approach allows avoiding drawbacks inherent to the packing of small diameter particles into narrow-bore tubes as-well as the tedious fabrication of retaining frits. Inspired by the suspen- sion polymerization protocols applied to the synthesis of porous polymer beads, free radical polymerization remains the most widely used method for the design of such mono- lithic columns. Thermal initiation was first implemented for the free radical copolymerization of functional mono- mers and crosslinkers in the presence of porogenic sol- vents [5, 6]. Photochemically driven conditions were con- sidered for the first time in 1997 and proved well suited to the spatially controlled incorporation of monolithic mate- rials within the confines of microchannels [7]. These two initiation methods are compatible with (meth)acrylate and styrenic monomers offering the possibility for a vast range of separation applications. Zwitterionic/betaine, hydroxyl-, and amine-containing monomers have been used to prepare monoliths for the separation of hydrophilic solutes under normal phase [8], and hydrophilic interaction [9, 10] liquid (electro)chromatography conditions. Similar to the case of particulate stationary phases, a large number of studies aimed at applying monolithic Abstract A triphenylmethylamine-functionalized mono- lithic capillary column was newly designed for reversed- phase capillary electrochromatographic applications. Incorporation of the three phenyl rings-containing selector (also referred to as trityl selector) was achieved through post-polymerization functionalization of a generic mono- lithic matrix bearing nucleophilic-sensitive hydroxysuc- cinimide moieties. Such a 3D polymer matrix was obtained through UV-induced in situ free radical copolymerization of N-acryloxysuccinimide and ethylene dimethacrylate. The separation properties of the trityl monolithic capillary column were initially evaluated vis-à-vis polycyclic aro- matic hydrocarbons, as model hydrophobic compounds, and compared to the separation ability of a benzylamine- functionalized monolithic capillary column prepared using the same generic monolithic matrix. Electrochromato- graphic separation of phenols and anilines was also consid- ered, and our preliminary results suggest the occurrence of hydrophobic interactions due to the aromatic and non-polar nature of the surface-grafted trityl selector. The triphenyl monolithic capillary column exhibited relative standard deviation values (% RSD) below 4.1 % for the here-stud- ied chromatographic parameters, namely, retention factor, selectivity, resolution, and efficiency. * Benjamin Carbonnier carbonnier@icmpe.cnrs.fr 1 Université Paris-Est, ICMPE (UMR7182), CNRS, UPEC, 94320 Thiais, France 2 Département de Biologie, Laboratoire de Biochimie Appliquée, Faculté des Sciences, Université Ferhat Abbas, 19000 Sétif, Algeria