Development of a LC-MS/MS method using stable isotope dilution for the quantification of individual B6 vitamers in fruits, vegetables, and cereals

Abstract

Vitamin B6 comprises an important set of molecules tightly interwoven with the human amino acid, fatty acid, and carbohydrate metabolism. Analytical methods striving for the quantification of individual B6 vitamers so far mostly rely on methods based on HPLC in combination with fluorescence detection, but their application encounters multiple difficulties due to the chemical divergence of the single vitamers. The present study describes the development of a method based on LC-MS/MS and stable isotope dilution assay (SIDA) for the simultaneous quantification of five vitamers (PN, PL, PM, PMP, and PNG) of the B6 group in food samples. [13C3]-PN, [13C3]-PL, and [13C6]-PNG were applied as internal standards for the analysis of PN, PL, and PNG. PM and PMP were quantified via matrix-matched calibration referring to [13C3]-PN. The developed method was validated using starch matrix. The limits of detection and quantification ranged from 0.0028 to 0.02 mg/kg and from 0.0085 to 0.059 mg/kg, respectively, for all analytes. Calculated recoveries varied from 92 to 111%. Intra-injection precisions ranged from 0 to 9%, inter-day precisions from 4 to 10%, and intra-day precisions from 4 to 10%. A total of 14 plant-based food samples including fruits, vegetables, and cereals were examined for their content of vitamin B6 using the validated method. Furthermore, the first quantitation of PNG without enzymatic steps or divergent internal standards was undertaken utilizing LC-MS/MS and SIDA.

Native Microbiome Members of C. elegans Act Synergistically in Biosynthesis of Pyridoxal 5′-Phosphate

“…CHNTR56 MYb120, combination and E. coli OP50, but not in Comamonas sp. 12022 MYb131; and (3) m/z values of major daughter ion in three carbon labeled PLP reported in a related study [15]. The isotope labeling strategy was successful in fully labeling PLP in Chryseobacterium sp.…”

Strategic Priorities of the Scientific Plan of the European Research Infrastructure METROFOOD-RI for Promoting Metrology in Food and Nutrition

“…The most critical bottleneck for using SIDAs is the availability of the stable isotope labelled standards, and, therefore, new SIDAs are mainly elaborated by scientists that are experienced in synthesising these compounds. For vitamins, SIDAs based on LC-MS/MS detection have been reported for the B6 group [ 81 ], the folates [ 82 , 83 ], and vitamin B12 [ 84 ]. For elements, SIDAs are mainly based on ICP-MS detection.…”

Quantitative Proton NMR Spectroscopy for Basic Taste Recombinant Reconstitution Using the Taste Recombinant Database

“…LC-MS/MS and HPIC analysis of all basic taste-active compounds is a time-consuming and cost-intensive process due to the implementation of various analysis and quantitation methods with different stationary phases for various substance classes, including calibration and evaluation. If stable isotope dilution analysis (SIDA) is required, e.g., in foods with complex matrixes, utilization of expansive isotopically labeled internal standards is necessary, and in addition, large amounts of highly purified solvents for chromatographic separation are needed. − We hereby present a fast and reliable quantitative 1 H NMR approach to reconstitute a BTR within one single measurement of a liquid food sample or of food extracts from a solid food. The comparison of observed proton spectra with reference spectra of main taste-active substances, such as l -amino acids, saccharides, nucleotides, and small organic acids included in our in house taste recombinant database (TRDB), combines identification and quantitation of all relevant compounds by qHNMR in one single step.…”