유현우 (한국표준과학연구원, UST)

김병주 (한국표준과학연구원)

최기환 (한국표준과학연구원)

김병주 (한국표준과학연구원)

유현우 (한국표준과학연구원, UST)

최기환 (한국표준과학연구원)

A method based on isotope dilution liquid chromatography-tandem mass spectrometry with supramolecular solvent for accurate determination of vitamin B₁₂ in tuna has been developed. ¹³C- labeled cyanocobalamin was used as an internal standard. The supramolecular solvents are nanostructured liquids which are produced through self-assembly and coacervation process. A decanol-tetrahydrofuran (THF) alkanol-based supramolecular solvents were applied to eliminate matrix interference. Using the reversed-phase C18 column, the four forms of vitamin B₁₂ were successfully separated on the chromatogram. This separation allowed for the effective monitoring of the conversion of adenosylcobalamin, methylcobalamin, and hydroxocobalamin into cyanocobalamin. A pseudo-cobalamin in tuna was identified by verifying differences in mass fragmentation between these pseudo-cobalamins and cobalamin; they were excluded from the final vitamin B₁₂ measurement results. MS was operated with the positive electropray ionization and the LC-MS/MS measurement parameters were optimized to achieve improved ionization efficiency. The method validation for the developed method, which includes accuracy and reproducibility will be conducted.

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