Spectrophotometric determination of triclosan in personal care products

A spectrophotometric method for the determination of triclosan in personal care products was proposed. It was based on the reaction of sodium nitrite with p-sulfanilic acid in an acidic medium to form diazonium ion, with which triclosan further formed an azo compound in an alkaline medium. The resulting yellow colored product has a maximum absorption at 452 nm. A good linear relationship (r = 0.9999) was obtained in the range of 0–30 mg L⁻¹ triclosan. A detection limit of 0.079 g L⁻¹ was achieved and the relative standard deviation was 0.24% (n = 11) at 14 mg L⁻¹ triclosan. The proposed method has been applied to the analyses of triclosan in several personal care products and the results were in good agreement with those obtained by high-performance liquid chromatography.