A new coupling of ionic liquid based-single drop microextraction with tungsten coil electrothermal atomic absorption spectrometry

In this work, an improved method of ionic liquid based-single drop microextraction (IL-SDME) preconcentration was firstly coupled with tungsten coil electrothermal atomic absorption spectrometry (W-coil ET-AAS) detection. The new coupling was developed and applied for the determination of ultra-trace cadmium. Experimental parameters influencing the performance of IL-SDME as well as instrumental conditions were studied systematically, including IL-drop volume, chelating agent concentration, pH, stirring rate and time, heating program of W-coil ET-AAS, flow rate of carrier gas. Under the optimal conditions, the limit of detection (LOD) for cadmium was 0.015 μg L−1 (sampling amount on W-coil was 10 μL). The sensitivity enhancement factor was 42, while the improvement factor of LOD was 33. The established method was applied to determine cadmium in standard reference materials of rice and real water samples successfully. The developed IL-SDME-W-coil ET-AAS coupling represents a simple, green and highly sensitive method for cadmium determination.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► IL-SDME was firstly coupled with W-coil ET-AAS. ► Applications of SDME and W-coil ET-AAS were greatly expanded. ► Sensitivity of W-coil ET-AAS for detection of Cd was greatly improved. ► The coupling is a simple method with impressive detectability and novelty.