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Determination of four forms of vitamin B 12 and other B vitamins in seawater by liquid chromatography/tandem mass spectrometry
Author(s) -
Heal Katherine R.,
Carlson Laura Truxal,
Devol Allan H.,
Armbrust E. Virginia,
Moffett James W.,
Stahl David A.,
Ingalls Anitra E.
Publication year - 2014
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7040
Subject(s) - chemistry , seawater , chromatography , mass spectrometry , tandem mass spectrometry , b vitamins , medicine , oceanography , geology
RATIONALE Vitamin B 12 is an essential nutrient for more than half of surveyed marine algae species, but methods for directly measuring this important cofactor in seawater are limited. Current mass spectrometry methods do not quantify all forms of B 12 , potentially missing a significant portion of the B 12 pool. METHODS We present a method to measure vitamins B 1 , B 2 , B 6 , B 7 and four forms of B 12 dissolved in seawater. The method entails solid‐phase extraction, separation by ultra‐performance liquid chromatography, and detection by triple‐quadrupole tandem mass spectrometry using stable‐isotope‐labeled internal standards. We demonstrated the use of this method in the environment by analyzing B 12 concentrations at different depths in the Hood Canal, part of the Puget Sound estuarine system in Washington State. RESULTS Recovery of vitamin B 12 forms during the preconcentration steps was >71% and the limits of detection were <0.275 pM in seawater. Standard addition calibration curves in three different seawater matrices were used to determine analytical response and to quantify samples from the environment. Hydroxocobalamin was the main form of B 12 in seawater at our field site. CONCLUSIONS We developed a method for quantifying four forms of B 12 in seawater by liquid chromatography/mass spectrometry with the option of simultaneous analysis of vitamins B 1 , B 2 , B 6 , and B 7 . We validated the method and demonstrated its application in the field. Copyright © 2014 John Wiley & Sons, Ltd.