Isolation and analysis of vitamin B12 from plant samples

Based on increased demands of strict vegetarians, an investigation of vitamin B-12 content in plant sources, was carried out. The vitamin B-12 concentration was determined by RP-HPLC with UV detection, after prior matrix isolation by immunoaffinity chromatography (IAC). Vitamin B-12 was extracted in the presence of sodium cyanide, to transform all forms of cobalamin into cyanocobalamin. Diode array detector was used to monitor vitamin B-12, after its chromatographic separation under gradient elution with a mobile phase consisting of acetonitrile and trifluoroacetic acid 0.025% (w/v). The method demonstrated excellent linearity with a limit of detection 0.004 mu g/ml. The method precision was evaluated for plant samples and it was below 0.7% (n = 6). Significant amounts of vitamin B-12 in plants were detected in Hippophae rhamnoides (37 g/100 g dry weight), in Elymus (26 mu g/100 g dry weight) and in Inula helenium (11 mu g/100 g dry weight). (C) 2016 Elsevier Ltd. All rights reserved.