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ARS Home » Northeast Area » Beltsville, Maryland (BHNRC) » Beltsville Human Nutrition Research Center » Food Composition and Methods Development Laboratory » Research » Publications at this Location » Publication #172868

Title: SOLID PHASE EXTRACTION- LIQUID CHROMATOGRAPHY METHOD FOR THE DETERMINATION OF NIACIN IN COMMERCIAL FLOUR PRODUCTS

Author
item Lacroix, Denis
item Wolf, Wayne
item Carter, Sumiko
item CROWLEY, EMILY - 1235-15-00

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2007
Publication Date: 7/17/2007
Citation: Lacroix, D.E., Wolf, W.R., Carter, S.A., Crowley, E. 2007. Solid phase extraction- liquid chromatography method for the determination of niacin in commercial flour products. Cereal Chemistry, 84(2):116-118.

Interpretive Summary: A previously reported SPE/LC protocol, following acid digestion to convert niacinamide to nicotinic acid, was modified to give complete LC separation of nicotinic acid from endogenous interfering peaks in commercial flours. Niacin values obtained with this procedure agreed with assigned values for NIST Reference Material Flours. For four enriched commercial 'all-purpose' wheat flour matrices, niacin values ranged from 104% to 163% of the declared label value. Manufacturers commonly provide increased levels of enriched vitamins to insure shelf-life compliance with FDA nutritional labeling requirements. This method was also successful for niacin determination in rice flour, corn meal flour, pancake mix, and baking flour mix matrices. Values found in these other flour products ranged from 60-128% of the label declaration. The inclusion of appropriate standardized reference materials in the method validation process is important in providing traceability to analyte values of the recognized standard. These data will be used by food testing and analysis laboratories in the public and private sectors in response to food labeling regulations.

Technical Abstract: A previously reported SPE/LC protocol, following acid digestion to convert niacinamide to nicotinic acid, was modified, by using a poly (styrene-divinylbenze) trimethyl ammonium anion-exchange (Alltech Anion-R) LC column and by increasing the mobil phase flow rate, to give complete LC separation of nicotinic acid from endogenous interfering peaks in commercial flour samples. Niacin values obtained with this procedure agreed with assigned values for NIST Reference Material Flours. For four enriched commercial 'all-purpose' wheat flour matrices, niacin values ranged from 104% to 163% of the declared label value. Manufacturers commonly provide increased levels of enriched vitamins to insure shelf-life compliance with FDA nutritional labeling requirements. This method was also successful for niacin determination in rice flour, corn meal flour, pancake mix, and baking flour mix matrices. Values found in these other flour products ranged from 60-128% of the label declaration. The inclusion of appropriate standardized reference materials in the method validation process is important in providing traceability to analyte values of the recognized standard.