title: Sensitive voltammetric determination of thymol in essential oil of Carum copticum seeds using boron-doped diamond electrode.
abstract: Essential oil of Carum copticum seeds, obtained from a local shop, was extracted and content of thymol was analyzed using square-wave voltammetry at boron-doped diamond electrode. The effect of various parameters, such as pH of supporting electrolyte and square-wave voltammetric parameters (modulation amplitude and frequency), was examined. In Britton-Robinson buffer solution (pH 4), thymol provided a single and oval-shaped irreversible oxidation peak at +1.13 V versus silver/silver chloride potassium electrode (3M). Under optimal experimental conditions, a plot of peak height against concentration of thymol was found to be linear over the range of 4 to 100μM consisting of two linear ranges: from 4 to 20μM (R(2)=0.9964) and from 20 to 100μM (R(2)=0.9993). The effect of potential interferences such as p-cymene and γ-terpinene (major components in essential oil of C. copticum seeds) was evaluated. Thus, the proposed method displays a sufficient selectivity toward thymol with a detection limit of 3.9μM, and it was successfully applied for the determination of thymol in essential oil of C. copticum seeds. The Prussian blue method was used for validation of the proposed electroanalytical method.
authors.affiliation: Innovation Center of the Faculty of Chemistry, University of Belgrade, 11158 Belgrade, Republic of Serbia. Electronic address: dalibors@chem.bg.ac.rs.
authors.forename: Dalibor M
authors.initials: DM
authors.lastname: Stanković
mesh_terms: D001895:Boron / Q000737:chemistry*; D029974:Carum / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D009822:Oils, Volatile / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D013943:Thymol / Q000032:analysis*; D013997:Time Factors
chemical_list: D009822:Oils, Volatile; D013943:Thymol; D018130:Diamond; D001895:Boron
keywords: Boron-doped diamond electrode; Carum copticum seeds; Thymol