The task specific ionic liquid (TSIL), tricaprylmethylammonium thiosalicylate ([A336] [TS]), was synthesized, characterized and subsequently used as extraction solvent in dispersive liquid-liquid microextraction (DLLME) technique. The TSIL-DLLME method followed by inductively coupled plasmaatomic emission spectrometry (ICP-AES) was applied to determination of trace mercury (Hg) and cadmium (Cd) in aqueous sample solutions. The significant parameters of the extraction process were optimized using a response surface methodology. Under the optimal conditions (pH, 6.50; concentration of TSIL, 47.50 mg m/ L; and salt concentration, 8.50% (w/v)), the analytical figures of merit for Hg and Cd were obtained as: LDR, 1-5000 mg/L; determination coefficients (R2), 0.9990 and 0.9991; LODs (limit of detections), 0.28 and 0.22 mg/ L; RSD, 1.1% and 1.0%, respectively. In addition, the removal of Hg2+ and Cd2+ ions by the plant Dracaena sanderiana was investigated using the developed method. The Hg and Cd uptake and storage by the plant from contaminated waters was also evaluated to be approximately equal to 10.32 and 30.90 mg/kg, respectively. The relative recoveries of Hg and Cd were 97.50% and 92.37%, respectively.