Green spectrophotometric techniques for simultaneous evaluation of triclosan and chlorhexidine in some personal care products

Three accurate, rapid, simple, inexpensive, and green spectrophotometric techniques were developed for the simultaneous determination of triclosan and chlorhexidine in binary mixture in some personal care products. Second derivative zero-crossing technique at 235.07 nm and 249.59 nm was used for determination of triclosan at 242.00 nm and 293.72 nm for chlorhexidine in the linearity ranges 3.0-20.0, 6.0-20, 8.0-40.0, and 1.0-40.0 µg/mL respectively. The second method ratio spectra derivative and third method, mean centering ratio derivative spectra were used for determination of triclosan and chlorhexidine in binary mixture. The linearity ranges for both methods were (1.0-20.0 and 1.0-40.0 µg/mL). The recovered values ranged from 96.52% to 100.72%, with an RSD% of less than 3.94%. The proposed method’s selectivity was tested using synthetic mixture created in the lab and evaluated by standard addition method. The results of proposed methods were compared using one-way ANOVA and the output showed no significant between the suggested methods. The proposed methods are successfully applied for determination of triclosan and chlorhexidine in toothpaste samples. Lastly, an assessment of the environmental impact of the proposed techniques was conducted utilizing the green analytical procedure index and analytical eco-scale approaches as a measure of the "greenness" profile. KEY WORDS: Derivative spectrophotometry, Ratio spectra derivative method, Mean centering ratio derivative spectra, Triclosan, Chlorhexidine, Greenness measurement Bull. Chem. Soc. Ethiop. 2025, 39(9), 1661-1674. DOI: https://dx.doi.org/10.4314/bcse.v39i9.1