Determination of vitamin B12 in milk products and selected foods by optical biosensor protein-binding assay: method comparison.
Biomolecular interaction analysis was evaluated for the automated determination of vitamin B12 in a range of foods. The analytical technique was configured as a biosensor-based, nonlabeled inhibition protein-binding assay using nonintrinsic R-protein. Sample extraction conditions were optimized, and both ligand specificity and nonspecific binding considerations were evaluated. Performance parameters included a quantitation range of 0.08-2.40 ng/mL, recoveries of 89-106%, agreement against assigned reference values for 3 independent certified food reference materials, and a mean between-laboratory reproducibility relative standard deviation of 4.9%. The proposed method was compared with reference microbiological and radioisotope protein-binding methods for a range of food samples. A wide selection of milks, infant formulas, meats, and liver were evaluated for their vitamin B12 content. The influence of season was studied in herd milk, early lactation was followed for a single animal, and the cobalamin content of bovine, caprine, and ovine milks was compared.
Indyk
Harvey E
HE
NZMP-Fonterra, Waitoa, New Zealand. harvey.indyk@nzmp.com
Persson
Bjorn S
BS
Caselunghe
Malin C B
MC
Moberg
Anna
A
Filonzi
Enrico L
EL
Woollard
David C
DC
D000818:Animals; D015374:Biosensing Techniques; D002138:Calibration; D002417:Cattle; D003611:Dairy Products / Q000382:microbiology*; D005260:Female; D005516:Food Microbiology; D006041:Goats; D007202:Indicators and Reagents; D008892:Milk / Q000382:microbiology*; D011485:Protein Binding; D015203:Reproducibility of Results; D012621:Seasons; D012756:Sheep; D014805:Vitamin B 12 / Q000032:analysis*
D007202:Indicators and Reagents; D014805:Vitamin B 12