L-Tryptophan as Fluorescent Probe for Determination of Folic Acid in Pharmaceutical Products

Keywords: Folic acid, L-Tryptophan, Pharmaceutical tablet, Spectrofluorimetry


A new fluorescent probe L-Tryptophan was reported for the determination of folic acid (FA), based on its quenching effect of the fluorescence intensity of L-Tryptophan. The concentration of folic acid was proportional to the quenched fluorescence intensity of L-Tryptophan at an emission wavelength of 365 nm in Britton– Robinson (BR) buffer solution of pH 7. Optimized conditions of pH, time, order of addition of the reagent, potential interferences, concentrations of L-Tryptophan and buffer were investigated. Folic acid was determined in a linear range of 2.0 to 16.0 μg ml-1 with a correlation coefficient R2 0.9974. The limits of detection LOD and quantification LOQ values were 0.09 μg ml-1 and 0.27 μg ml-1, respectively. The standard deviation (RSD) values for five replicated measurements of 2, 8, 16 μg ml-1 folic acid were between 0.23 % and 1.07%. This method is efficient for routine analysis and quality control assay as it is relatively interferences free.


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Author Biographies

Tara F. Tahir, Department of Medical Microbiology, Faculty of Science and Health, Koya University, Koya KOY45, Kurdistan Region - F.R. Iraq

Tara F. TAhir is a lecturer of Analytical Chemistry at the Chemistry Department, Faculty of Science and Health, Koya University. She joined the work at Koya University since 2007 as assistant lecturer. Before that she was assistant lecturer at the University of Sulaimani, Collage of Science (2001-2006). She has gained a B.Sc. degree in Chemistry from Collage of Science, Salahaddin University on 1994, M.Sc. degree in Analytical Chemistry from University of Sulaimani on 2001, and Ph.D. degree in Environmental Electrochemistry from Universiti Sains Malaysia, Malaysia, on 2013. She was a director of postgraduate Department in College of Science at University of Sulaimani in 2001-2002. Dr. Tara was head of Chemistry Department from (2013 - 2017) and she was Vice Dean in (2014 - 2015) at the same time. She is an associate editorial board of ARO Journal of Koya University. She is a consultant of Environmental Board of Ministry of Higher Education and Scientific affairs. She has publications in appreciable impact factor journals. Her research interests are; sensors and voltammetric analysis.

Aryan F. Qader, Department of Chemistry, Faculty of Science and Health, Koya University, Koya KOY45, Kurdistan Region

Aryan F. Qader is an assistant lecturer in the Department of Chemistry, Faculty of Science and Health at Koya University. He has received his B.Sc. in Chemistry at Koya University in 2011 and his MSc. in Analytical Chemistry from College of Education at University of Salahaddin in 2016.

Musher I. Salih, Department of Chemistry, Faculty of Science and Health, Koya University, Koya KOY45, Kurdistan Region

Musher I. Salih is a lecturer at the Department of Chemistry, Faculty of Science and Health, Koya University. He has received his B.Sc. in Chemistry at Koya University in 2010 and his M.Sc. in Biochemistry at the University in 2014. He has four published articles.

Essa Q. Rashid, Kurdistan Medical Control Agency, Kurdistan Region - F.R. Iraq

Essa Q. Rashid works as an assistant director at KMCA (Kurdistan Medical Control Agency) of Kurdistan Region of Iraq. He has received his B.Sc. in Chemistry at Salahaddin University in 2010 and his M.Sc. in Clinical Biochemistry at the Department of Biochemistry in Hawler Medical University in 2016.


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How to Cite
Tahir, T. F., Qader, A. F., Salih, M. I. and Rashid, E. Q. (2019) “L-Tryptophan as Fluorescent Probe for Determination of Folic Acid in Pharmaceutical Products”, ARO-THE SCIENTIFIC JOURNAL OF KOYA UNIVERSITY, 7(2), pp. 19-26. doi: 10.14500/aro.10557.