Emara S.Masujima T.Zarad W.Kamal M.Ei-Bagary R.Pharmaceutical Chemistry DepartmentFaculty of PharmacyMisr International UniversityKm 28 Ismailia RoadCairoEgypt; Analytical Molecular Medicine and Devices LaboratoryHiroshima UniversityGraduate School of Biomedical Sciences1-2-3KasumiMinami-kuHiroshima734-8551Japan; Pharmaceutical Analytical Chemistry DepartmentFaculty of PharmacyModern Sciences and Arts University26 July Mehwar Road intersection with Wahat Road6 October CityEgypt; Pharmaceutical Chemistry DepartmentFaculty of PharmacyCairo UniversityKasr El Aini St.Cairo 11562Egypt2020-01-092020-01-092013219665https://doi.org/10.1093/chromsci/bms170PubMed ID 23097580https://t.ly/1VMzLScopusA simple, sensitive, and selective online pre-column derivatization high-performance liquid chromatographic method was developed and validated for the first time to determine trace levels of folic acid (FA). An oxidant cerium (IV) trihydroxyhydroperoxide packed reactor was used for pre-column oxidation and was combined by column switching with a C18 analytical column for sample enrichment and separation. The method was based on oxidative cleavage of FA into highly fluorescence products, 2-amino-4-hydroxypteridine-6-carboxaldehyde and the corresponding 2-amino-4-hydroxypteridine-6-carboxylic acid, during the flow of 0.04 M phosphate buffer (pH 3.5) containing the analyte through packed reactor at a flow rate of 0.2 mL/min and 40�C. The fluorescent products were enriched on the head of the analytical column for the final separation. The separation was performed at room temperature using a mobile phase consisting of phosphate buffer (0.04 M, pH 3.5) and acetonitrile (90:10, v/v). The eluents were monitored at emission and excitation wavelengths of 463 and 367 nm, respectively. The method showed excellent recovery, precision and accuracy with detection limits of 0.067 ng/mL from 500 L of sample FA. The developed method was successfully applied to the determination of FA in pharmaceutical formulations and showed a recovery of 99.31% and a relative standard deviation of 1.72%. 2012 � The Author [2012].Englishceriumfolic acidperoxidearticlechemistryequipmenthigh performance liquid chromatographyisolation and purificationlimit of detectionmethodologypHreproducibilitystatistical modeltemperatureCeriumChromatography, High Pressure LiquidFolic AcidHydrogen-Ion ConcentrationLimit of DetectionLinear ModelsPeroxidesReproducibility of ResultsTemperatureArticlehttps://doi.org/10.1093/chromsci/bms170PubMed ID 23097580