MASS SPECTRAL DETERMINATIONS OF THE FOLIC ACID CONTENT OF FORTIFIED BREADS FROM CHILE

Authors: Pawlosky, Robert; HERTRAMPF, EVA - UNIVERSITY OF CHILE, SANT; Flanagan, Vincent; Thomas, Paul

Submitted to: Journal of Food Composition and Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2003
Publication Date: 4/30/2003
Citation: Pawlosky, R.J., Hertrampf, E., Flanagan, V.P., Thomas, P.M. 2003. Mass spectral determinations of the folic acid content of fortified breads from chile. Journal of Food Composition and Analysis. 16:281-286.

Interpretive Summary: Folic Acid (FA) fortified bread samples (n=64) collected from bakeries near Santiago, Chile were assayed for their FA content using a mass spectrometry procedure. Samples were spiked with an internal standard (13C-labeled FA) and then extracted and analyzed using mass spectrometry. The precision of the method was 3.8% and the method was accurate over a typical concentration range (100-900 nanogram per gram of bread). It was found that 80% of the samples met or exceeded the fortification goals. In 38% of the bread samples, the concentrations of FA, was within targeted values (151 - 264 microgram per gram). Only nineteen percent of the samples had FA concentrations that were below 151 ug g-1 This work demonstrated that in a random sampling of breads from Chile, FA was found in concentrations consistent with a fortification program.

Technical Abstract: Sixty-four samples of fortified bread collected from bakeries from Santiago, Chile were assayed for their folic acid (FA) content using high performance liquid chromatography-mass spectrometry (LC-MS). A 13C-labeled analogue of FA was spiked into each sample as an internal standard and the analyte was extracted from bread, purified on a solid phase cartridge, and analyzed by LC-MS using electrospray ionization. The relative standard error for the precision of the method was 3.8% based on the replicate analyses (n=5). The accuracy of the method was determined using a standard method of addition of the analyte into bread samples and FA was quantified over a range that bracketed the fortification levels (100-900 ng g-1 of bread). Fourteen samples were also assayed using a microbiological assay (L. casei) and the mean variation in the values as determined by the microbiological assay and the LC-MS method was on the order of 10%. In 38% of the bakery samples, the concentrations of FA, was within targeted values (151 and 264 ug g-1). Nineteen percent of the samples had FA concentrations that were below 151 ug g-1 and 43% of the samples exceeded the upper level.