Spectrophotometric Determination of Thymol in Pure and Lesterine Mouth washing


A simple and sensitive spectrophotometric method for the determination of Thymol in pure and pharmacetical drugs form has been described. This Method was based on the diazotization of the drug by sodium nitrite in acidic medium at 5Cº .This was followed by coupling with ortho-aminobenzoic acid to form yellow colored azo dye stabilized and measured at 390 nm. Beer’s law was obey in the concentration range of 1-10μg ml-1.The molar absorptivity and Sandell’s sensitivity were 1.4x105 L mole-1 cm-1, 0,009 μg cm-1 respectively. The detection limit and the limit of quantitation were 0,0082 μg ml-1, 0,027 μg ml-1 respectively .All variables including the reagent concentration, reaction time, colour stability period, and mole ratio were studied in order to optimize the reaction conditions.No interferences were observed.Results of analysis were validated statistically and by recovery studies.These methods are successfully employed to determine thymol in some oral solution.The developed method is easy to use and accurate for routine studies relative to HPLC and other techniques.