title: Voltammetric determination of melatonin using a graphene-based sensor in pharmaceutical products.
abstract: Melatonin can be sensitively detected in pharmaceuticals by cyclic voltammetry and fixed-potential amperometry using a graphene-based sensor. The sensor characterization of cyclic voltammetry constantly provides high values of electrode active area and heterogeneous rate constant. In optimal conditions, the sensor was applied for the determination of melatonin in different pharmaceutical samples. The sensitivity to melatonin was 0.0371 A M(-1), and the limit of detection was 0.87×10(-6) M. The data obtained by using the graphene-based sensor for the detection of melatonin in pharmaceutical products were in good agreement with the data provided by the producer. Since no interferences from the excipients were found, using a separation technique was not necessary. Additionally, the low price, ease of handling, small amount of sample, short time per analysis, and possibility of automation are the important advantages that recommend this methodology for quality control of pharmaceuticals.
authors.affiliation: Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmacy, "Dunarea de Jos" University of Galati, Galati, Romania.
authors.forename: Irina Mirela
authors.initials: IM
authors.lastname: Apetrei
authors.affiliation: Department of Chemistry, Physics and Environment, Faculty of Sciences and Environment, "Dunarea de Jos" University of Galati, Galati, Romania.
authors.forename: Constantin
authors.initials: C
authors.lastname: Apetrei
mesh_terms: D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006108:Graphite; D057230:Limit of Detection; D008550:Melatonin / Q000032:analysis*; D004364:Pharmaceutical Preparations / Q000032:analysis; D012680:Sensitivity and Specificity
chemical_list: D004364:Pharmaceutical Preparations; D006108:Graphite; D008550:Melatonin
keywords: chitosan; electroanalysis; kinetics; limit of detection; recovery