Optimization of an online post-column derivatization system for ultra high-performance liquid chromatography (UHPLC) and its applications to analysis of biogenic amines.

We investigated the efficacy and utility of a post-column derivatization method for the detection of amines with o-phthalaldehyde (OPA) in ultra high-performance liquid chromatography (UHPLC). Since it was anticipated that a derivatization reaction system placed downstream of the column would give considerable band broadening to narrow peaks generated by a UHPLC column, we examined the contributions of the dimensions of the reaction tube, the fluorescence (FL) detector flow cell, and the column to the extra-column peak broadening, and optimized the post-column derivatization system in UHPLC. We successfully separated amines within 6 min with gradient elution by using the post-column derivatization system connected to a UHPLC system.

High-throughput comprehensive analysis of D- and L-amino acids using ultra-high performance liquid chromatography with a circular dichroism (CD) detector and its application to food samples.

A rapid and comprehensive analytical method for D- and L-enantiomers of proteinogenic amino acids was developed using ultra-high performance liquid chromatography (UHPLC) equipped with a circular dichroism (CD) detector. Pre-column derivatization reagents were examined for enhanced sensitivity and selectivity for UV and CD detection: 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) was selected. The method, using a CD detector, does not require separation of optical isomers on a column to calculate the enantio ratio (%D) using the g-factor value and produces a simple chromatogram in comparison to other reported methods.

Calibration of an evaporative light-scattering detector as a mass detector for supercritical fluid chromatography by using uniform Poly(ethylene glycol) oligomers.

The quantitativeness of an evaporative light-scattering detector (ELSD) for supercritical fluid chromatography (SFC) was evaluated by using an equimass mixture of uniform poly(ethylene glycol) (PEG) oligomers. Uniform oligomers, in which all molecules have an identical molecular mass, are useful for the accurate calibration of detectors. We calibrated the SFC-ELSD system for various concentrations and molecular masses by using an equimass mixture of PEG oligomers.