Simultaneous determination of tumour biomarkers homovanillic acid, vanillylmandelic acid, and 5-hydroxyindole-3-acetic acid in human urine using single run HPLC with a simple wall-jet glassy carbon electrochemical detector

HPLC with amperometric detection (HPLC-ED) was used for the simultaneous determination of tumour biomarkers homovanillic acid (HVA), vanillylmandelic acid (VMA), and 5-hydroxyindole-3-acetic acid (5-HIAA) in one run in human urine using inexpensive lab-made glassy carbon wall-jet detector. Simple and fast solid phase extraction was used instead of earlier used more time consuming liquid-liquid extraction. Simultaneous determination of the three analytes in one run is fast with limits of detection at micromolar concentrations; amperometric detection is more sensitive and selective than the spectrophotometric one. Calibration dependences are linear in the concentration range from 20 to 150 mu molL(-1). Interferences of other compounds present in urine were not observed for HPLC-ED. Concentrations of tumour biomarkers in urine of healthy volunteer found by HPLC-ED correspond with previously published normal physiological concentrations.