Liquid chromatography-mass spectrometry method for isomer separation and detection of sugars, phophorylated sugars and organic acids v1

This standard operating procedure is used to achieve effective separation of a wide range of polar metabolites found in central carbon metabolism via a hybrid liquid chromatographic method (ion-exchange chromatography and hydrophilic interaction liquid chromatography (HILIC)) using an Intrada Organic Acid column (Imtakt) coupled with triple quadrupole mass spectrometry. This method gives improved resolution while showing enhanced sensitivity for the detection of low abundance phosphorylated sugars compared with standard HILIC methods.

Enhancement of teprenone isomer separation by subcritical fluid chromatography using porous graphitic carbon column

Teprenone is a therapeutic anti-ulcer agent developed in Japan. As described in the Japanese Pharmacopoeia (JP) 17th Edition, gas chromatography/hydrogen flame ionization detection (GC/FID) and high-performance liquid chromatography/ultraviolet detection (HPLC/UV) have been used for the assay of active pharmaceutical ingredients (APIs) and teprenone capsules, respectively. The critical aspect of the assay is a separation of the structural isomers (mono-cis and all-trans) of teprenone. Herein, we propose an improved quantitative method for the quality control of teprenone in APIs and capsules via subcritical fluid chromatography/photo diode array detection (SubFC/PDA) using a porous graphitic carbon column. SubFC conditions, i.e., type and content of the organic modifier in the mobile phase, column temperature, injection volume, and flow rate, were optimized. The developed SubFC/PDA method was validated according to ICH guidelines Q2(R1) in terms of accuracy, precision (repeatability and intermediate precision), specificity, linearity, quantification range, robustness, and stability. Comparison of SubFC/PDA method with the GC/FID or HPLC/UV method (described in JP) revealed that the SubFC/PDA method gave better resolution and run time than the JP methods. The developed SubFC/PDA method is expected to be useful for pharmaceutical analysis or quality control of teprenone isomers.

Modulating the stacking modes of nanosized metal–organic frameworks by morphology engineering for isomer separation

A morphology engineering method was utilized to modulate the stacking modes of three nano-NU-901 materials, leading to different separation abilities for isomers.

Separation of Fatty Acid Dimethyl Esters on an Ionic Liquid Gas Chromatographic Column

An ionic liquid (IL) 111 column was compared with other commonly employed stationary phases including polydimethyl siloxane and polyethylene glycol for the separation of fatty acid monomethyl and dimethyl esters. The fatty acid esters employed in this study were derived from metathesis reactions of vegetable oils both with and without olefins. The IL 111 column demonstrated enhanced performance compared with conventional columns for the separation of these esters. These advantages included significantly enhanced retention of dimethyl esters relative to monomethyl esters, excellent cis/trans isomer separation and the ability to analyze higher carbon number dimethyl esters. As a result, these columns are highly suited for the analysis of mixtures of mono- and dimethyl fatty acid esters found in lipid metathesis reaction products or to determine monofunctional impurities in samples of commercial dimethyl esters.