AFS Determination of Trace Cadmium in Water by Solid-Phase Extraction with Magnetic Multi-Walled Carbon Nanotubes

A method of atomic fluorescence spectrometry combine with magnetic solid-phase extraction was established for the determination of trace cadmium in water. Magnetic multiwalled carbon nanotubes were synthesized,and used as a solid-phase extraction sorbent for extraction and concentration of trace cadmium in water. Then cadmium was detected by hydride generation-atomic fluorescence spectrometry. Under optimized conditions,the linear range of cadmium was 0.05-5.0 μg·L-1,with detection limit (3σ) of 1.6 ng·L-1. The recovery rates measured by standard addition method were in the range of 97.1%-101%,with RSD were in the range of 1.6%-4.8%. The method was used for the analysis of standard substance,giving results in agreement with the certified values.