Folic acid-fortified flour: optimised and fast sample preparation coupled with a validated high-speed mass spectrometry analysis suitable for a fortification monitoring program.

摘要

In Australia, folic acid (FA) has been mandatorily added to bread making flour (non-organic wheat flour) since September 2009. The objective of FA fortification is to reduce the prevalence of neural tube defects. This study validated a quantitative assay to determine FA in fortified flour using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). For this purpose, a procedure of aqueous extraction followed by solid phase extraction (SPE) was developed for isolating FA from fortified flour samples. SPE using phenyl cartridges is more selective and avoids the high sodium concentrations used to elute FA from ion exchange sorbents. The validated method is linear over the range 0.024-14 mug/g flour. Absolute recovery of FA was 89 %; inter-day variability coefficient of variation (CV) was 11 % and limit of detection (LOD) was 9.8 ng/g flour. The experimental data revealed that the majority of commercially fortified bread premixes and flour had mean FA concentrations lower than the minimum mandated level of 200 mug/100 g flour. The findings of this study support the need for regular monitoring of actual fortification levels by the Australian States and Territories. copyright Springer Science+Business Media New York 2013.