New analyser for the determination of urinary vanillylmandelic acid, homovanillic acid and creatinine.
We have developed a novel analyser for the determination of vanillylmandelic acid, homovanillic acid and creatinine in urine by high-performance liquid chromatography using three different types of column, cation-exchange, anion-exchange and reversed-phase and the column-switching technique. In this procedure, 10 microliters of intact urine were directly injected into the cation-exchange column, and the pass-through fraction, containing vanillylmandelic acid and homovanillic acid was transferred to the anion-exchange column by column switching. The fraction partially purified from endogenous urinary impurities on the anion-exchange column was transferred to the reversed-phase column. Vanillylmandelic acid and homovanillic acid, separated by the solvent-switching technique, were detected fluorimetrically (excitation at 280 nm, emission at 320 nm). Then, creatinine eluted from the cation-exchange column is spectrophotometrically detected (254 nm). Therefore the successive simultaneous analysis of the three could be performed in a 15-min cycle; the within-assay coefficients of variation for normal and patients' urines were less than 1.9%, less than 3.3% and less than 3.0% for vanillylmandelic acid, homovanillic acid and creatinine, respectively; the recoveries averaged 100, 103 and 100%, respectively, for supplemented urines.
Scientific Instrument Division, Tokyo Research Center, Tosoh Corporation, Kanagawa, Japan.
S
S
Kawaguchi
N
N
Hirachi
M
M
Fukamachi
D000838:Anions; D002412:Cations; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003404:Creatinine / Q000652:urine*; D006719:Homovanillic Acid / Q000652:urine*; D006801:Humans; D013050:Spectrometry, Fluorescence; D014642:Vanilmandelic Acid / Q000652:urine*
D000838:Anions; D002412:Cations; D014642:Vanilmandelic Acid; D003404:Creatinine; D006719:Homovanillic Acid