Desenvolvimento e validação de metodologias analíticas para a determinação de triclosan e triclocarban em produtos de higiene pessoal.

Abstract

Triclosan and triclocarban are used in personal care products like soaps, deodorants, toothpastes as antimicrobial agents in order to preserve them. The objective of this work was to develop two analytical methods through two different techniques using experimental designs. HPLC was used for the determination of triclosan and triclocarban simultaneously and UV-Visible spectrophotometry for the determination of triclosan, both applied to personal care products. For the chromatographic method from a Doehlert design, the conditions were optimized obtaining the optimal condition with a 250 mm C18 column, flow of 0.8 mL min-1 and temperature of 40.0°C, the mobile phase was methanol: water in the ratio 80:20 (v/v). For the spectrophotometric method, the screening of variables with significant effects was investigated by a complete 23 factorial design followed by a central composite design in order to find the optimal condition for the formation reaction of the colored compound generated with triclosan, detectable in the spectrophotometer of UVVisible absorption. Sulfanilamide concentration of 0.088% and hydrochloric acid of 0.038 mol L-1 were found to be the optimal condition for the best absorbance value. Both methods were validated following the parameters established by Anvisa, all being within the recommended standards. The linear range was 1.0-10 µg mL-1 for TCS and TCC in HPLC and 0.050-10 for TCS in UV-Visible spectrophotometry with correlation coefficients greater than 0.99 and detection limits of 0.011 µg mL-1 for TCS and 0.29 µg mL-1 for TCC by HPLC and 0.018 µg mL-1 for TCS by UV-Visible. The methods were used in the determination of analytes in personal hygiene products, obtaining recoveries within the required limits with deviations below 5%, being able to be applied to the analyzed samples with accuracy and adequate precision. All samples containing TCS had concentrations around the value of 0.3% according to the legislation and the sample containing TCC presented a value above that recommended by the competent body.