A Method for the Determination of Nicotinic Acid in Whole Blood by High-Performance Liquid Chromatography with UV Detection

Abstract

We devised a method featuring column-switching high-performance liquid chromatography for the determination of nicotinic acid (NiA) in human blood. Nicotinamide in blood was converted into NiA by heating with 10mol/l sodium hydroxide at 100°C for 50min. The reaction mixture was adjusted to pH 2.3 with hydrochloric acid, and applied to a Baker bond spe octadecyl column. NiA on the column was eluted with 60% methanol, and measured by HPLC. The calibration curve for NiA was linear over the range 10 to 1015 ng/injection. The lower limit of detection of NiA in blood was 0.5μg/ml. NiA (extract) was stable at room temperature in room light for at least 25 hr. The rate of recovery of NiA from blood was 89% in the range 1.01 to 10.08μg/ml blood. The reproducibilities (CV) for within-and between-day assays were 4.4% (n=10) and 6.7 % (n=5), respectively.