Desarrollo de una técnica analítica sencilla para la cuantificación de Dietiltoluamida en soluciones repelentes

Introduction: The global increase in arboviruses, driven by climate change and the expansion of the Aedes aegypti mosquito, has increased the demand for topical repellents and favored the local production of N,N-diethyl-meta-toluamide (DEET)-based formulations during public health emergencies. In this context, the availability of simple and accessible analytical methodologies for quality control presents a challenge, especially in small-scale production settings where chromatographic techniques such as HPLC are not always available. Objective: To develop and evaluate a UV-visible spectroscopy-based method for quantifying DEET in simple alcoholic formulations. Materials and methods: Four independent calibration curves were developed in the 0.05–0.30 mg/mL range. Analytical performance was evaluated through statistical regression analysis and residual analysis, along with studies of specificity, repeatability, accuracy, and determination of the limits of detection and quantification. Results and discussion: 264.0 nm was established as the working wavelength, and a linear response was obtained in the studied range (R² = 0.9951). No evidence of heteroscedasticity, autocorrelation, or lack of fit of the linear model was observed; likewise, no interferences attributable to the vehicle or excipients were detected, with a recovery of 100.28 ± 3.15%. Its application to manually prepared formulations and to a 20 kg production batch allowed for the quantification of DEET content within the specifications established by current regulations. Conclusion: The results demonstrate that the developed method represents an accessible, low-cost analytical option with adequate repeatability, ideal for the routine quality control of locally produced alcoholic DEET solutions.