Ionic liquids as stationary phases in gas chromatography—an LSER investigation of six commercial phases and some applications

Abstract

The separation properties of six novel stationary phases for gas chromatography, commercially available from Sigma-Aldrich (Supelco) and based on ionic liquids (ILs), were investigated. The linear solvation energy relationship model (LSER) was used to describe the molecular interactions between these stationary phases and 30 solutes. The solutes belong to different groups of compounds, like haloalkanes, alcohols, ketones, aromatics, aliphatics, and others. A good description of different interactions, as described by the LSER model, could be achieved. The calculated values of system constants for the ionic liquid phases were compared with constants of commonly used standard phases like a 5 % phenyl/95 % dimethyl siloxane and a polyethylene glycol phase. The solute descriptors are in good agreement with those found by previous authors who have used the LSER model for 44 different ionic liquids as stationary phase. The experiments were carried out at two temperatures to evaluate the influence on the phase parameters and separation characteristics. The interactions of different functional groups with the IL phases are discussed. These novel IL phases are a promising replacement of or an addition to common polar phases. Based on the evaluated phase properties, several possibilities for applications of these novel phases are shown.

In Silico Modeling of Hundred Thousand Experiments for Effective Selection of Ionic Liquid Phase Combinations in Comprehensive Two-Dimensional Gas Chromatography

“…(141 – 2)!] × 2) for each sample separation was established from the LSER database of all the columns at 100 °C and based on calculated O values (see Table S1 for the compiled LSER database of all columns). ,,− Briefly, retention factors ( k ) of all analytes on a particular column are calculated as where c is an intercept constant. e , s , a , b , and l (stationary phase descriptors) represent the stationary phase contributions to the interactions being dispersity, dipolarity, H-bond with acid functionalities, H-bond with basic functionalities, and dispersion/cavity formation for gas to liquid phase, respectively.…”

Chiral Separations by Capillary Electrophoresis and related Techniques with Different Chiral Selectors: A Review

“…ILs are successfully adapted in separation methods such as SP in GC [223], mobile phase additives in HPLC [224] and solvent in solid-liquid or liquid-liquid phase extraction [225]. Applications of ILs in CE are applied in the form of an electrolyte, buffer additives, surface coating or chemical derivatization of the capillary inner wall [226].…”

Direct Classification of GC × GC-Analyzed Complex Mixtures Using Non-Negative Matrix Factorization-Based Feature Extraction

“…Biota tissues and environmental media contain many polar and ionic chemicals, so they are often analyzed by liquid chromatography, electrophoresis, 2,3 and gas chromatography using polar stationary phases or after derivatizing nonvolatile chemicals. 4 Nonpolar chemicals are mainly analyzed by gas chromatography. Recent advances in two-dimensional gas chromatography (GC × GC) have made it a powerful technique for comprehensively analyzing polar and semipolar chemicals.…”

“…Methods for comprehensively analyzing mixtures are of interest because they make it possible to decrease the complexity involved in assessing chemical mixtures. Biota tissues and environmental media contain many polar and ionic chemicals, so they are often analyzed by liquid chromatography, electrophoresis, , and gas chromatography using polar stationary phases or after derivatizing nonvolatile chemicals . Nonpolar chemicals are mainly analyzed by gas chromatography.…”