Development of a novel acidic task-specific ionic liquid-based effervescence-assisted microextraction method for determination of triazine herbicides in tea beverage

In this study, a simple, rapid, sensitive and eco-friendly effervescence-assisted microextraction method was established for the determination of triazine herbicides in tea beverage samples. For the first time, acidic task-specific ionic liquid [C₄mim][HSO₄] was utilized not only as extraction solvent, but also as Brønsted acid to generate carbon dioxide which can enhance mass transfer between extraction solvent and analytes. Extraction parameters, including amounts of ionic liquid and sodium bicarbonate, concentration of salt, pH value of the sample solution and volume of elution solvent, were evaluated. Under the optimal conditions, the developed method had good linearity in the range of 1–200 ng mL⁻¹ or 2–200 ng mL⁻¹ with the correlation coefficients higher than 0.9990. Additionally, minimum detection and quantification limits were 0.08 ng mL⁻¹ and 0.25 ng mL⁻¹, respectively, precision was in the satisfactory range of 0.8%–9.3%, and recovery of the herbicides from the real samples, which was varied from 76.3% to 135.9%, was in the acceptable range. Moreover, stability of the analytes in sample solution and robustness of the experiment were measured and obtained satisfactory results. In addition, the method does not require external energy supplied by an external source or apparatus. These results demonstrate that the method could be applied for determining trace triazine herbicides in beverage samples.