Nitritocobalamin and nitrosocobalamin may be confused with sulfitocobalamin using cation-exchange chromatography

UMMS Affiliation

Department of Medicine, Division of Preventive and Behavioral Medicine

Publication Date


Document Type



Animals; Brain Chemistry; Chickens; Chromatography, Ion Exchange; Cobalt Radioisotopes; Diet; Hydroxocobalamin; Male; Nitroso Compounds; Radioisotope Dilution Technique; Sulfites; Vitamin B 12


Bioinformatics | Biostatistics | Epidemiology | Health Services Research


The previously reported ability of SP-Sephadex C25 column chromatography for partitioning biologically important cobalamins has been modified to include analytical separation of nitritocobalamin (NO2-Cbl) and nitrosocobalamin (NO-Cbl). Gel column dimensions (1.5 x 11.0 cm), a low eluent flow-rate (125 microliters/min), collection of small eluate fractions (160 microliters) plus maintenance of He saturated mobile and gel phases all combined to eliminate ordinarily confusing proximal elution of NO2-Cbl and NO-Cb1 with sulfitocobalamin (SO3-Cbl) and cyanocobalamin. Cobalamin elution profiles from the gel column were monitored by direct radiometric analysis of 57Co-labelled cobalamin standards or competitive intrinsic factor radioassays for cobalamin sample sizes up to 10.0 ng. Failure to implement the chromatographic conditions detailed here totally obscured analysis of NO2-Cbl coexisting with SO3-Cbl in brain tissues for chicks exposed to dietary sulfites and caused oversight of NO-Cb1 normally coexisting in prepared NO2-Cbl standards.


J Chromatogr B Biomed Appl. 1994 Oct 3;660(1):180-5.

Journal/Book/Conference Title

Journal of chromatography. B, Biomedical applications

PubMed ID


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