Simultaneous determination of kynurenine and kynurenic acid concentrations in human serum by HPLC with dual wavelengths fluorescence detection

A validated liquid chromatography‐high resolution‐tandem mass spectrometry method for the simultaneous quantitation of tryptophan, kynurenine, kynurenic acid, and quinolinic acid in human plasma

“…Due to its importance in linking different kinds of disease with inflammation, metabolite profiling of intermediates of the kynurenine pathway has gained a lot of interest in medical research. Although a number of analytical methods have been presented for the analysis of kynurenine pathway intermediates, such as gas chromatography‐mass spectrometry , capillary electrophoresis‐mass spectrometry , liquid chromatography with UV, fluorescence or electrochemical detection , and liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) , the reliable and simultaneous quantification of TRP, KYN, KYNA and QUIN in biological samples is still a challenging task.…”

Optimization of Zn2+-containing mobile phase for simultaneous determination of kynurenine, kynurenic acid and tryptophan in human plasma by high performance liquid chromatography

“…Some authors [14,17,23,24] delivered Zn 2+ through post-column. Others [5,9,10,[25][26][27][28][29] simply used a Zn 2+ -containing mobile phase by addition of 0.1-0.5 mol/L ZnAc 2 with or without pH adjustment. So high concentration of ZnAc 2 would cause technical solubility problem and clotting risk which could hamper HPLC procedures and results [8,25].…”

“…Others [5,9,10,[25][26][27][28][29] simply used a Zn 2+ -containing mobile phase by addition of 0.1-0.5 mol/L ZnAc 2 with or without pH adjustment. So high concentration of ZnAc 2 would cause technical solubility problem and clotting risk which could hamper HPLC procedures and results [8,25]. Though acidifying mobile phase with HAc could reduce the clotting risk, low pH would cause severe interference with the formation of the chelate complex of KYNA-Zn 2+ and reduce fluorescence intensity [19].…”

Development of a fluorimetric detection method for cinnabarinic acid using ortho‐tolyl hydrazine as the derivatization reagent

“…Compared with the other metabolites of Trp, such as KYN or KYNA, few studies have been conducted on the biological actions caused by CA. In fact, although analytical methods for KYN or KYNA have often been reported (Xiao et al, 2008;Mitsuhashi et al, 2006Mitsuhashi et al, , 2007Fukushima et al, 2007a, b), the determination method for CA was only reported by Christen et al (1992b). In that study, they determined CA by high-performance liquid chromatography (HPLC), with spectrophotometric and/or electrochemical detection (ECD).…”