A microwave-assisted extraction method combined with magnetic ionic liquid-based dispersive liquid-liquid microextraction for the extraction of chloramine-T from fish samples prior to its determination by high-performance liquid chromatography

In the present work, a combination of microwave-assisted extraction with magnetic ionic liquid-based dispersive liquid-liquid microextraction was developed for the extraction of chloramine-T from fish samples. In this method, the sample was mixed with a hydrochloric acid solution and exposed to microwave irradiations. By doing so, chloramine-T was converted to p-toluenesulfonamide and extracted from the sample into an aqueous phase. Then, a mixture of acetonitrile (as a dispersive solvent) and magnetic ionic liquid (as an extraction solvent) was rapidly injected into the obtained solution. In the following, the magnetic solvent droplets including the extracted analytes were isolated from the aqueous solution in the presence of an external magnetic field and after diluting with acetonitrile injected into high-performance liquid chromatography equipped with a diode array detector. Under the optimum extraction conditions, high extraction recovery (78%), low limits of detection (7.2 ng/g) and quantification (23.9 ng/g), good repeatability (relative standard deviations <= 5.8 and 6.8% for intra- and inter-day precisions, respectively), and wide linear range (23.9-1000 ng/g) were obtained. Finally, various fish samples marketed in Tabriz city (East Azarbaijan, Iran) were analyzed with the suggested method.