A novel method of combining solid phase extraction with solidified floating organic drop microextraction for speciation of inorganic arsenic in wastewater samples by electrothermal vaporization ICP-MS

Abstract

In this work, a novel method of combining solid phase extraction (SPE) with solidified floating organic drop microextraction (SFODME) was developed for the speciation of inorganic arsenic in wastewater samples by electrothermal vaporization inductively coupled plasma mass spectrometry. In the SPE step, titanium dioxide nanotubes were used for preconcentration of the analytes and removal of the inorganic and organic matrix from the wastewater samples. The elution solution from the SPE was employed for further preconcentration and separation of the analytes with SFODME. The main factors affecting the separation and determination of the analytes were also examined in detail. Under optimal conditions, the detection limits of this method were 0.073 and 0.089 pg mL-1 with relative standard deviations of 5.9% and 4.7% for As(III) and As(V) (n=9, c=1.0 ng mL-1), respectively. This method was successfully applied for the speciation of inorganic arsenic in industrial wastewater, urban sewage, and certified reference material of water sample without any prereduction and pre-oxidation operation.