title: Analysis of B-6 vitamers in human milk by reverse-phase liquid chromatography.
abstract: A simple, accurate reverse-phase high performance liquid chromatography (RPLC) method was introduced for the analysis of B-6 vitamers in human milk. The assay consisted of a phosphate buffer (pH 2.9) delivered isocratically through 5 micron ODS column packing, followed by post-column bisulfite derivatization to enhance the detection of PLP (and to a minor extent PL). The vitamers were detected using a fluorescence spectromonitor. Sample run time was less than 30 min. The sensitivity of the method was such that PL, PN, and PLP were detectable to 30 pmol/ml milk and PM and PMP to 5 pmol/ml milk. Total vitamin B-6 content in milk analyzed by RPLC correlated well with the microbiological assay. B-6 vitamer distribution in human milk was similar to values obtained from two different ion-exchange HPLC systems. The RPLC procedure is simpler and faster than the HPLC systems and is suggested for future use in analysis of B-6 vitamer concentrations in human milk.
mesh_terms: D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005260:Female; D006801:Humans; D008895:Milk, Human / Q000032:analysis*; D011730:Pyridoxal / Q000032:analysis; D011732:Pyridoxal Phosphate / Q000032:analysis; D011733:Pyridoxamine / Q000031:analogs & derivatives / Q000032:analysis; D011736:Pyridoxine / Q000032:analysis*; D012440:Saccharomyces / Q000187:drug effects
chemical_list: D011730:Pyridoxal; D011732:Pyridoxal Phosphate; D011733:Pyridoxamine; D011736:Pyridoxine; C010627:pyridoxamine phosphate