Valko-Rokytovská M, Očenáš P, Salayová A and Kostecká Z
An ultra-high-performance chromatography for simultaneous separation and determination of the phenylalanine, tyrosine and their metabolites (vanillylmandelic acid, homovanillic acid, homogentisic acid), tryptophan and its metabolites (5-hydroxyindolacetic acid, kynurenic acid, indoxylsulphate, 3-indolacetic acid) was developed. The separation was carried out on Thermo Scientific AcclaimTM 120 C18 column with a mobile phase composed of methanol and water (containing 0.1% formic acid) in gradient mode at a flow rate of 0.6 mL/min. The limit of detection of 10-15 ng/mL and limit of quantitation of 29-45 ng/mL were determined. The method was evaluated in terms of recovery, precision, linearity, limit of detection, limit of quantification. The determined parameters are in the commonly acceptable ranges for that kind of analysis. The developed chromatographic method allows the rapid screening of urine metabolites, which can serve as potential markers of various tumor diseases as well as for the monitoring of treatment processes.