Quantitation of urinary niacin metabolites by reversed-phase liquid chromatography

The niacin metabolites N1-methyl-2-pyridone-5-carboxamide (2-PYR) and N1-methylnicotinamide (N-MN) have been quantified in human urine using isocratic reversed-phase high-performance liquid chromatography with ultraviolet detection after a simple anion-exchange clean-up procedure. The coefficients of variation (%) of the method for 2-PYR and N-MN were 6.3 and 6.8, respectively, and the limits of detection (mg/1 urine) were 0.05 for 2-PYR and 0.20 for N-MN. Results by this method compared favorably with those obtained by established techniques. It is a straight forward, rapid, and sensitive procedure for the assessment of niacin status.