Determination of Niacin in Food Materials by Liquid Chromatography Using Isotope Dilution Mass Spectrometry

• Published in: Journal of AOAC International Vol. 90; no. 4; pp. 1084 - 1089
• Main Authors: Goldschmidt, R.J, Wolf, W.R
• Format: Journal Article
• Language: English
• Published: Gaithersburg, MD AOAC International 01.07.2007; Oxford University Press
• Subjects: analysis; Animals; Biological and medical sciences; breakfast cereals; Cations; chemical composition; chemistry; Chemistry Techniques, Analytical; Chemistry Techniques, Analytical - methods; Chromatography; Chromatography - methods; Chromatography, Ion Exchange; Chromatography, Ion Exchange - methods; Chromatography, Liquid; Chromatography, Liquid - methods; dried milk; Food; food analysis; Food Analysis - methods; Food industries; Fundamental and applied biological sciences. Psychology; hard red spring wheat; Identification and classification; isotope dilution technique; Isotope dilution techniques; Liquid chromatography; Mass spectrometry; Mass Spectrometry - methods; metabolism; Methods; Milk; Milk - metabolism; Models, Chemical; Niacin; Niacin - analysis; Niacin - chemistry; Reproducibility of Results; reversed-phase high performance liquid chromatography; Solid Phase Extraction; Spectrometry, Mass, Electrospray Ionization; Spectrometry, Mass, Electrospray Ionization - methods; Testing; vitamin content; wheat flour; whole milk; United States; Isotope dilution; Liquid chromatography; Mass spectrometry; Nicotinic acid; Materials; Food
• ISSN: 1060-3271; 1944-7922
• DOI: 10.1093/jaoac/90.4.1084

The availability of deuterium-labeled nicotinic acid makes stable isotope dilution mass spectromerty (MS) coupled with liquid chromatography (LC) an attractive option for the determination of the water-soluble B-vitamin niacin in food samples. A method was developed based on acid digestion, solid-phase extraction with a strong cation exchange column, and reversed-phase chromatography with a C18 column. Detection is by positive ion electrospray MS. Analysis in selected ion recording mode is subject to interference problems similar to those found with other LC determinations of niacin, but the additional selectivity of multiple reaction monitoring mode largely eliminates interference problems. The method was applied to 6 different food matrixes and to appropriate reference materials, including milk samples with niacin levels near 1 ppm. The method exhibited good accuracy, based on levels obtained for the reference materials, and relative standard deviations in the range of 0.55%.