A new method for the determination of Vitamin B12 in seawater

Despite the environmental importance of Vitamin B-12, there is no direct method for B-12 quantification in natural waters. Bioassay is the only protocol currently available to measure B-12 in the marine environment. Here we report a new method for the direct determination of B-12 in seawater based on C-18 solid-phase extraction and quantification by Reversed-Phase High-Performance Liquid Chromatography (HPLC) with an UV-Vis detector. The detection limit of the B-12 protocol was of the order of 0.042 ng l(-1). The method was successfully applied to the determination of Vitamin B-12 in filtered coastal seawater. Concentrations of Vitamin B-12 in the coastal environment ranged 3-605 ng l(-1) with spike recoveries between 92 and 99%. (C) 2004 Elsevier B.V. All rights reserved.