Application of multiwalled carbon nanotubes as a solid-phase extraction sorbent for chlorobenzenes

Carbon nanotubes are novel and interesting nanomaterials in the field of nanometer research because of their many unique electronic, mechanical, and chemical properties. Therefore, the application of carbon nanotubes in analytical chemistry is of great interest. In our work, a trace enrichment method based on the application of multiwalled carbon nanotubes (MWNTs) as a solid-phase extraction (SPE) sorbent for chlorobenzenes was developed. The SPE conditions affecting extraction recoveries, including the sample volume, the type of eluents, the volume, and the flow rate of eluent, were optimized. The adsorption characteristic was compared between MWNTs and current SPE sorbents, including C-18 silica and activated carbon. The results showed that the adsorption capacities of MWNTs, C18 bonded silica, and activated carbon for 1,2-dichlorobenzene at an equilibrium concentration of 90 mug/mL were 237, 189, and 150 mg/g, respectively. The results also showed that MWNTs had higher extraction recoveries for chlorobenzenes. This method would be applied to the determination of chlorobenzenes as well as persistent organic pollutants (POPs) in natural and polluted waters.