Spectrophotometric Triclosan Analysis at 452 nm

The application describes the method to determine the precise amount of triclosan in personal care products. The absorption of colored azo derivative of Triclosan is measured at a wavelength of 452 nm using a  UV/VIS Excellence spectrophotometer.

How is Triclosan Determined using UV Vis Spectrophotometry?

Triclosan is commonly used in personal care products because of its antibacterial and antifungal properties. It is a stable and lipophilic compound, which is widely found in river water, lake water, sediments, fish, and even human milk. Hence, it is a concern of environmental fate. According to European Economic Community Council directive 76/768 (Annex VI) the maximum authorized concentration of triclosan in cosmetics is not more than 0.3 % (w/w).

This application is based on a derivatization experiment. First, sodium nitrite reacts with p-sulfanilic acid in an acidic medium to form a diazonium ion. Subsequently, the formed diazonium ion is added to triclosan to form a yellow-colored azo compound in an alkaline medium. The absorption of this derived yellow-colored product is measured at a wavelength of 452 nm using a METTLER TOLEDO UV/VIS Excellence spectrophotometer.