Spectrophotometric determination of thymol in pharmaceutical preparation via diazotization reaction with 4-aminoacetophenone

الملخص EN

A simple and sensitive spectrophotometric method is proposed for the determination of thymol.

The method is based on the coupling reaction of the drug with diazotised 4-aminoacetophenone reagent in alkaline medium to produce an intense red coloured water-soluble and stable azo dye which exhibits a maximum absorption at 502 nm.

Beer’s low is obeyed over the concentration range 0.2–16 µg / ml with a molar absorptivity of 2.89 × 104 L.mol-1.cm-1.

The limit of detection is 0.0216 µg / ml and the limit of quantitation is 0.072 µg / ml, average recovery is 101.6 %, and RSD is less than 2.4 %.

The proposed method is applied successfully to the determination of thymol in pharmaceutical preparation.