Simultaneous Determination of Kynurenine and Kynurenic Acid by High-Performance Liquid Chromatography Photoirradiation System Using a Mobile Phase Containing 18-crown-6

• Published in: International journal of tryptophan research Vol. 12; p. 1178646919834551
• Main Authors: Atsumi, Motomasa, Mawatari, Ken-ichi, Morooka, Akari, Yasuda, Makoto, Fukuuchi, Tomoko, Yamaoka, Noriko, Kaneko, Kiyoko, Nakagomi, Kazuya, Oku, Naoto
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 2019; Sage Publications Ltd
• Subjects: Acids; Amino acids; Chromatography; Hydrogen peroxide; Ions; Metabolites; Original Research; Potassium; Retention; Spectrum analysis; Standard deviation; Japan; post-column UV irradiation; hydrogen peroxide; fluorescence detection; high-performance liquid chromatography; kynurenine; 18-crown-6; kynurenic acid
• ISSN: 1178-6469; 1178-6469
• DOI: 10.1177/1178646919834551

A high-performance liquid chromatography (HPLC) system has been developed for the fluorometric determination of kynurenine (KYN) and kynurenic acid (KYNA) in human serum using a mobile phase containing 18-crown-6. A retention time of KYNA was adjusted with pH of phosphate buffer in 18-crown-6. KYN and KYNA were separated on a CAPCELLPAK C18 (250 × 4.6 mm i.d.). The mobile phase consisted of 35 mmol/L phosphate buffer (pH 8.0)/methanol (85/15, v/v) containing 35 mmol/L hydrogen peroxide and 10 mmol/L 18-crown-6. The retention times of KYN and KYNA were 18and 24 minutes, respectively. The calibration graphs of KYN and KYNA were linear over the range 180 to 2900 and 1 to 84 nmol/L by injecting a 50-μL volume of KYN and KYNA, respectively. Pretreatment of serum was achieved by deproteinization only. The mean recoveries of KYN and KYNA from serum were more than 97%.