Gas Chromatographic Enantioseparation of Fluorinated Anesthetics: Single‐Column Performance and Scale‐up Estimation

Abstract

Results of a study devoted to provide the pure enantiomers of isoflurane and desflurane from racemic mixtures using gas chromatography are presented. For that purpose, a cyclodextrin‐based selector described in earlier work was immobilized on porous glass beads. The adsorption isotherms were determined and applied to predict operating parameters which provide the highest possible productivity of the separation. The analysis included evaluation of the performance of larger columns applying simplifying scale‐up considerations. Using repetitive batches, the method can provide per day with a laboratory scale column approximately 1 g pure enantiomer. Selected model predictions were validated experimentally.

Structural Changes of Hierarchically Nanoporous Organosilica/Silica Hybrid Materials by Pseudomorphic Transformation

“…Additionally,s ignificant change is seen in Qs pecies. Before the pseudomorphic transformation, the ratio of Q 3 (Si(OSi) 3 (OR')) to Q 4 (Si(OSi) 4 )s ignals is nearly 1:1, whereas after transformation, the intensity of Q 3 signal increases significantly and becomes dominant. This behavior can also be observedf or pure CPG after pseudomorphic transformation,i mplying that the silica phase is affected by the transformation process as well (Figure S8).…”

“…Controlled pore glasses (CPGs) and ordered mesoporous silicas, which are formedb yt he liquid-crystal template mechanism and often referred to as micellar-templated silicas (MTS), are two classes of porous silica-based materials that are both established in numerous fields of applications, for example,c atalysis, [1,2] chromatography, [3,4] gas adsorption [5,6] or enzyme immobilization. [7,8] CPGs can be synthesized in versatile shapes from monoliths to granules in the micrometerrange.…”

Chiral 1H NMR Analysis of Carbonyl Compounds Enabled by Cationic Cobalt Complex

“…The great importance of optically active (chiral) compounds in synthetic, medicinal, and biological chemistry continues to advance the search for rapid and facile methods to determine the identity, concentration, and relative ratio of chiral molecules . Such chiral analysis has been successfully performed with conventional chromatographic methods using high-performance liquid chromatography (HPLC) or gas chromatography (GC) . However, the utilization of 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy with chiral solvating agents (CSAs) has gained continuous attention as a complementary analytical technique. , In principle, the CSAs provide distinctive 1 H NMR signals obtained from two in-situ -formed diastereomeric adducts between the enantiopure CSA and the two enantiomers of the analyte of interest through noncovalent interactions, such as ion pairing, H bonding, or dipole–dipole interactions .…”