Development and Validation of a GC-ECD Method for the Determination of Trifluralin in Acetonitrile with Uncertainty Estimation

The use of trifluralin herbicide has raised concerns due to its persistence in the environment and potential toxicological impacts on human health and ecosystems. The aim of this study was to develop and validate a simple and reliable method for determining trifluralin residues in acetonitrile using gas chromatography with an electron capture detector (GC-ECD). The method was developed using internal standard calibration and validated in accordance with international guidelines. Validation parameters included LOD, LOQ, selectivity, linearity, precision, accuracy (recovery and bias) and measurement uncertainty. The method demonstrated high selectivity with no interfering peaks at the trifluralin retention time. A strong linear relationship was observed in the concentration range of 4-11 µg/g with a correlation coefficient (R2) of 0.9996. The precision, expressed as relative standard deviation (%RSD) was found 3.84% across all levels. Recovery values ranged from 98.45% to 100.06%, with % bias between 0.06% and 1.55% confirming the method accuracy. The expanded uncertainty was estimated to be 9.86% primarily influenced by sample and internal standard (IS) peak areas. The validated GC-ECD method provides a reliable, precise and accurate approach for quantifying trifluralin residues in environmental and food samples. It is suitable for routine monitoring, regulatory applications and risk assessments in agricultural and environmental contexts.