Determination of vitamin B5 in a range of fortified food products by reversed-phase liquid chromatography-mass spectrometry with electrospray ionisation

Methods for Vitamin B-5 determination in food products remain limited by their low sensitivity and poor selectivity. Here, we have developed a liquid chromatography-mass spectrometry (LC-MS) method for Vitamin B-5 determination in wide range of fortified food products. Vitamin B-5 was extracted from food samples by heat treatment and analysed by LC-MS in the positive mode using electrospray ionisation (ESI). Vitamin B-5 was quantified using hopantenic acid (HOPA) as internal standard after their separation on a C-18 narrow-bore column with a gradient of mobile phase made of water/acetonitrile and trifluoroacetic acid (TFA) 0.025%. MS with single ion monitoring mode at mass m/z 220 was used for Vitamin B-5 quantification. Calibration curve between 0.5 and 10 mug/ml of Vitamin B-5 was linear (r(2)=0.9993) and the detection limit was determined to be 800 pg. The overall quantitative efficiency of the method was evaluated using Nestle reference sample (infant formula). The intra-assay RSD was 4.8% (n=8), the inter-assay RSD 6.4% (n=4) and the recoveries of the spiked samples were above 95%. Application of the LC-MS method to Vitamin B-5 determination in wide range of fortified food products including three US National Institute of Standards and Technology (NIST) reference samples (RM 8435, RM 8415 and SRM 1546) shows consistent results with those obtained by microbiology and recoveries of Vitamin B-5 between 93 and 104% for the spiked samples. (C) 2003 Elsevier B.V. All rights reserved.