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Determination of urinary pyrraline by solid-phase extraction and high performance liquid chromatography.

Pyrraline is one of the advanced glycation end products formed under non-enzymatic and non-oxidative conditions in vivo. In this study, we developed a novel method for determination of urinary pyrraline using solid-phase extraction as a pretreatment procedure prior to determination by high performance liquid chromatography (HPLC). The Oasis HLB solid-phase extraction cartridge was used for pretreatment of urine samples without hydrolysis. The chromatogram obtained clearly revealed the peak for urinary pyrraline owing to prior removal of interfering substances in urine samples. The recovery rate of pyrraline was 97.2+/-3.3% (n=6). The mean excretion level of urinary pyrraline in healthy control (20-77 years old, n = 30) was 1.42+/-0.65 micromol/mmol creatinine, and the daily variation in the excretion level was considered to be insignificant. We propose the above procedure as a simple, rapid, and accurate method for determination of pyrraline levels in urine.