Ionic liquid as separation enhancer in thin-layer chromatography of biosurfactants: mutual separation of sodium cholate, sodium deoxycholate and sodium taurocholate

Abstract

Background: Physiological biosurfactants plays an important role in digestion of lipids and cholesterol also emulsifies fat-soluble vitamins. Methods: A new green thin-layer chromatographic system comprising ionic liquid (1-methylimidazolium chloride) impregnated silica gel G and 2-methyl tetrahydrofuran as stationary and mobile phases was found to be most suitable for the separation of ternary mixture of biosurfactants (sodium cholate, sodium deoxycholate and sodium taurocholate). The surface structure and chemical composition of silica gel G modified by impregnation with 1-methylimidazolium chloride were examined with the aid of scanning electron microscopy and energy-dispersive X-ray spectrophotometry, respectively.Results: Compared to plain silica gel, enhanced separation efficiency of ionic liquid impregnated silica gel was observed for the resolution of biosurfactants from their mixture. Chromatographic parameters such as ΔR F , separation factor (α) and resolution (R S ) for the separation were calculated. Effect of foreign substances (metal cations, inorganic anions, vitamins, amino acids and non-ionic surfactants as impurities) on the separation of surfactants was also examined. Effects of concentration level of 1-methylimidazolium chloride as impregnant and its substitution by other ionic liquids (1,2,3-trimethylimidazoliummethyl sulphate, 1-ethyl-3-methylimidazolium tetrafluoroborate) were also studied to decide the optimum experimental conditions for better separation possibilities. The limits of detection of sodium cholate, sodium deoxycholate and sodium taurocholate were calculated. Conclusion: A new green thin-layer chromatographic system comprising ionic liquid (1-methylimidazolium chloride) impregnated silica gel G and 2-methyl tetrahydrofuran as stationary and mobile phases provide the most suitable environment for the separation of ternary mixture of biosurfactants.

Chiral Pyrrolidinium Ionic Liquids with (−)‐Borneol Fragment in the Cation – Synthesis, Physicochemical Properties and Application in Diels‐Alder Reaction

“…The use of CILs based on (−)‐borneol, as solvents of the Diels‐Alder reaction did not allow to obtain the enantiomeric excess for any of the tested reactions. The reaction of crotonaldehyde with cyclopentadiene in [BC 2OH pyr][NTf 2 ] was slow at −30 °C, so it was decided to use Zn(OTf 2 ) as Lewis acid (Table 6), which is characterized by greater hydrolytic stability and activity compared to metal chlorides catalysts [51] . Lewis acids are an effective tool used to increase the reactivity of substrates and selectivity in the Diels‐Alder reaction.…”

“…The reaction of crotonaldehyde with cyclopentadiene in [BC 2OH pyr][NTf 2 ] was slow at À 30 °C, so it was decided to use Zn(OTf 2 ) as Lewis acid (Table 6), which is characterized by greater hydrolytic stability and activity compared to metal chlorides catalysts. [51] Lewis acids are an effective tool used to increase the reactivity of substrates and selectivity in the Diels-Alder reaction. The Zn(OTf 2 ) was used in the concentration of 1 molar% in relation to CA.…”