Simultaneous determination of L-arginine and dimethylarginines in human urine by high-performance liquid chromatography

L-Arginine (L-Arg), N-G,N-G-dimethylarginine (ADMA), N-G,N'(G)-dimethylargi nine (SDMA) can be simultaneously separated and measured from urine using o -phthaldialdehyde (OPA) as a fluorescent reagent by reversed-phase high-per formance liquid chromatography. Extraction of sample was not required, and derivatization can be directly performed after deprotein of sample. OPA-der ivatives were successfully resolved using a Nova-pak C-18 column (150 nun x 4.6 mm i.d.) with gradient program in 35 min. The mean recoveries Of L-Arg , ADMA and SDMA were over 97%. The relative standard deviations were lower 4.6 and 0.32% for amount and retention time, respectively. The detection li mits of the method are 1.0 pmol with signal-to-noise ratio is 3:1. Using th is method, the levels Of L-Arg, ADMA and SDMA in human urine were determine d. (C) 2001 Elsevier Science B.V. All rights reserved.