Determination of Deltamethrin Insecticide in Environmental Samples by Diazo-Coupling Reaction via Spectrophotometric Method

The aptitude to differentiate among various analytes is a vigorous feature of scientific exploration. In this study, a new azo dye exhibiting distinct sensing aptitudes was synthesized and characterized. Dye is the result of the interaction of deltamethrin insecticide with 5-amino-2-hydroxybenzoic acid in the alkaline medium at nearly pH 9 to form a stable yellow azo in the presence of acetone to enhance the solubility of deltamethrin insecticide. The formed compound was named Delta-P, and the maximum absorbance was detected at λmax 402 nm. UV-vis, FTIR, 1H-NMR, and 13C-NMR spectra were used to characterize the diazo coupling reaction generation. The mechanism by which deltamethrin binds to 5-amino-2-hydroxybenzoic acid was explained. The Beer-Lambert law is obeyed in the 3–60 µg/mL range, which is considered excellent linearity over a wide concentration range, with high sensitivity and reproducibility. The detection and quantification limits gained highlight the significant sensitivity of the synthesized azo dye, ensuring the method's applicability for trace-level analysis. Environmental samples, including water and soil, are successfully analyzed, confirming the method’s effectiveness. This finding indicates that the interaction can be used for colorimetric detection of deltamethrin in environmental samples and practical applications in quality control within agricultural and industrial settings.