Development of cost-effective dispersive liquid-liquid micro-extraction technique for preconcentration of multi-residue herbicides in environmental waters prior to Chromatographic analysis

High-density dispersive liquid-liquid microextraction method coupled with high-performance liquid chromatography with a diode array detector (HD-DLLME-HPLC-DAD) was developed for extraction and determination of six commonly used sulfonylurea herbicides in matrices of environmental waters. For simultaneous extraction of the target herbicides, the optimum experimental parameters that 024influence extraction efficiency were investigated. Under optimized conditions, the limit of detection (LOD) and quantification (LOQ) were 0.8-1.5 and 1.9-5.1 ng mL−1, respectively. The precisions in terms of relative standard deviations (% RSDs) of both intra-day and inter-day precisions (n = 6) were found to be 2.92 to 7.08 and 3.01 to 8.13, respectively. Furthermore, applicability of the developed method was investigated by analyzing spiked tap, lake, river and underground water samples and satisfactory recoveries were obtained in the range of 84.3–101.7% with RSDs < 9.8% (n = 6) and the target analytes were not detected in real samples. The proposed method offered several attractive features including fast analysis time, simplicity, sensitivity, and selectivity. Therefore, the trace level enrichment and assessment of sulfonylurea herbicides residues from environmental water matrices using HD-DLLME-HPLC-DAD could be utilized as a reliable alternative in routine laboratory analysis of contaminated environmental waters. KEY WORDS: Environmental water, High-density dispersive liquid-liquid microextraction, HPLC-DAD, Miniaturization analytical technique, Sulfonylurea herbicides, Trace level enrichment Bull. Chem. Soc. Ethiop. 2024, 38(5), 1189-1204.                                    DOI: https://dx.doi.org/10.4314/bcse.v38i5.1