Determination of nicotinic acid in serum by high-performance liquid chromatography with fluorescence detection.
A sensitive method for the determination of nicotinic acid in serum is described which employs high-performance liquid chromatography with fluorescence detection. Nicotinic acid and 2-chloronicotinic acid as an internal standard in deproteinized serum are reacted with N,N'-dicyclohexyl-O-(7-methoxycoumarin-4-yl)methylisourea in acetone to give the corresponding fluorescent 4-hydroxymethyl-7-methoxycoumarin esters. The compounds are separated by reversed-phase chromatography on LiChrosorb RP-18 with isocratic elution using aqueous acetonitrile containing a small amount of sodium 1-hexanesulphonate as a mobile phase. The detection limit of nicotinic acid in serum was 0.2 nmol/ml. The method requires only 100 microliters of serum.
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002855:Chromatography, Thin Layer; D006801:Humans; D009525:Niacin / Q000097:blood*; D013050:Spectrometry, Fluorescence
D009525:Niacin