title: Simultaneous determination of tetrahydrofolate, 10-formyltetrahydrofolate and 5-methyltetrahydrofolate in rat bile by high-performance liquid chromatography with electrochemical detection.
abstract: This report describes an analytical method for the measurement of tetrahydrofolate (H4PteGlu), 10-formyltetrahydrofolate (10-HCO-H4PteGlu) and 5-methyltetrahydrofolate (5-CH3-H4-PteGlu) in rat bile by high-performance liquid chromatography with electrochemical detection (HPLC-ECD). After diluting the bile sample with 0.2% sodium ascorbate solution, the sample was analyzed under the following conditions; (a) phenyl bonded phase column as an analytical column; (b) mobile phase consisting of 20 mM acetate buffer (pH 5.0) containing 0.1 mM EDTA; (c) an applied ECD potential of +300 mV; (d) 0.8 ml/min of flow rate. Under the above conditions, peaks of H4PteGlu, 10-HCO-H4PteGlu and 5-CH3-H4PteGlu in rat bile were well separated on the ECD-chromatogram. Detection limits of H4PteGlu, 10-HCO-H4PteGlu and 5-CH3-H4PteGlu were 0.13, 0.11 and 0.10 ng/ml, respectively, at S/N = 3. Bile excretion rates for H4PteGlu, 10-HCO-H4PteGlu and 5-CH3-H4PteGlu, which were analyzed by this method in rats, were 314 +/- 181, 321 +/- 179 and 449 +/- 198 ng/hr, respectively. Bile concentrations of the folates were more than 5,000 times higher than the detection limits for this method. This HPLC-ECD method is, therefore, a useful tool for bile folate analysis.
authors.affiliation: Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shimoda
authors.forename: H C
authors.initials: HC
authors.lastname: Shin
authors.forename: E
authors.initials: E
authors.lastname: Kokue
mesh_terms: D000818:Animals; D001646:Bile / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry; D005069:Evaluation Studies as Topic; D005260:Female; D002955:Leucovorin / Q000031:analogs & derivatives* / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013763:Tetrahydrofolates / Q000032:analysis*
chemical_list: D013763:Tetrahydrofolates; C010161:10-formyltetrahydropteroylglutamic acid; C030371:5,6,7,8-tetrahydrofolic acid; D002955:Leucovorin; C005984:5-methyltetrahydrofolate