Please cite this article in press as: S. Fanali, Nano-liquid chromatography applied to enantiomers separation, J. Chromatogr. A (2016), http://dx.doi.org/10.1016/j.chroma.2016.10.028 ARTICLE IN PRESS G Model CHROMA-357976; No. of Pages 15 Journal of Chromatography A, xxx (2016) xxx–xxx Contents lists available at ScienceDirect Journal of Chromatography A journal homepage: www.elsevier.com/locate/chroma Review article Nano-liquid chromatography applied to enantiomers separation Salvatore Fanali ∗ Institute of Chemical Methodologies, Italian National Research Council (C.N.R.), 00015, Monterotondo, Italy a r t i c l e i n f o Article history: Received 5 September 2016 Received in revised form 1 October 2016 Accepted 11 October 2016 Available online xxx Keywords: Chiral Enantiomers Selectors Nano-liquid chromatography Nano-LC Cyclodextrins Glycopeptide antibiotics Polysaccharides Vancomycin Teicoplanin Amylose Cellulose a b s t r a c t This paper presents the state of the art concerning the separation of chiral compounds by means of nano-liquid chromatography (nano-LC). The enantiomers’ separation and determination are a subject of fundamental importance in various application fields such as pharmaceutical industry, biomedicine, food, agrochemical etc. Nano-LC is a miniaturized chromatographic technique offering some advantages over conventional ones such as low consumption of mobile phase, sample volume and amount of chiral stationary phase, reduced costs etc. This is reported in the first part of the paper illustrating the features of the nano-LC. In addition, chiral resolution methods are briefly illustrated. Some chiral selectors, used in high-performance liquid chromatography have also been applied in nano-LC including cyclodextrins, glycopeptide antibiotics, modified polysaccharides etc. This is discussed in the second part of the review. Finally some examples of the applications available in literature are reported. © 2016 Elsevier B.V. All rights reserved. Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 2. Key features, instrumentation and usefulness of nano-LC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 3. Principles of enantiomers separation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .00 4. Chiral selectors and stationary phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 4.1. Chiral selectors added to the mobile phase or bonded to the capillary wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 4.2. Chiral selectors bonded or coated onto particles or monolithic stationary phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 4.2.1. Use of monolithic capillary columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 4.2.2. Use of packed capillaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 5. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 1. Introduction Nano-liquid chromatography (nano-LC) is a recent developed micro fluidic technique, mainly used for analytical purposes, offer- ing some advantages over conventional high-performance liquid ∗ Correspondence to: Institute of Chemical Methodologies, Italian National Research Council (C.N.R.), Area della Ricerca di Roma I, Via Salaria km 29.300-00015, Monterotondo, Italy. E-mail address: salvatore.fanali@cnr.it chromatography (HPLC). Because its features, this miniaturized technique has gained more and more interest in various application fields resulting either alternative and/or complementary to HPLC. Analytes separation takes place into capillary columns contain- ing selected stationary phases (SPs) under the effect of a mobile phase (MP) delivered at low flow rates (10–700 nL/min). The SP can be either coated or bonded to i) the capillary wall (open tubular-LC, OTLC), ii) particles (packed) and iii) silica or poly- meric (monoliths). The column (usually of fused silica material) has an I.D. in the range 10–100 m. Because of the reduced flow rate, nano-LC results in a higher mass sensitivity when compared http://dx.doi.org/10.1016/j.chroma.2016.10.028 0021-9673/© 2016 Elsevier B.V. All rights reserved.