Folate analysis by capillary electrophoresis

Folate congeners differing in polyglutamate chain length, oxidation state of the pteridine ring and in 5' and 10' substituents were resolved and quantified using capillary electrophoresis (CE). Tetrahydrofolate, folinic acid (leucovorin) and folic acid monomers were resolved using an uncoated silica capillary. Resolution of oxidized folates with glutamate chain lengths of 1, 3, 5, and 7 and methotrexate triglutamate was achieved with a DB17 capillary column. High resolution (100,000 theoretical plates) and short run times (<20 min) with adequate sensitivity (20 pg/peak) make CE ideal for resolving the multiplicity of folate species found in complex biologic matrices. CE should be useful in studies of folate nutriture and food folate bioavailability as well as in studies of folate and antifolate metabolism in cancer, rheumatoid arthritis and other contexts where quick and sensitive measurement of individual folate species would yield useful information. (Supported by Grant 95-80, University of Nebraska Medical Center).