Hydrophobic deep eutectic solvent-based DLLME for simultaneous determination of triazole fungicides in grain and water samples

This study aims to develop a dispersive liquid-liquid micro-extraction (DLLME) method for simultaneous determination of triazole fungicides (TFs). A hydrophobic molecular deep eutectic solvent (DES), composed of diphenylamine (DPA) and benzophenone (BZP) in a 1:1 molar ratio, was prepared as an extraction solvent for the adsorption of TFs. The rapid injection of a dispersion solvent containing the extraction solvent (DES) facilitated the extraction process, and phase separation was further accelerated through centrifugation. Under the optimal conditions, the proposed method provided a correlation coefficient greater than 0.993, with intra-day and inter-day RSDs ranging from 2.5% to 4.8% and 5.5% to 7.1%, respectively. The limits of detection and quantitation were found to be in the range of 0.5-1.0 ng mL − 1 and 1.6–3.3 ng mL − 1 , respectively. Enrichment factors ranged from 593 to 1380. Ultimately, the proposed extraction method successfully detected residual TFs, achieving relative recoveries between 84.6% and 109.6% in water, wheat, and rice samples. Furthermore, this study provides comparative insights into the presence of TFs in bran compared to hulled wheat samples. The findings demonstrate that the proposed DLLME method, based on a tailored hydrophobic DPA–BZP-1:1 DES, provides a simple, low-solvent, and selective sample preparation strategy, offering an effective methodological alternative for the routine monitoring of triazole fungicide residues in agricultural products and environmental samples.