Trace-chitosan-wrapped multi-walled carbon nanotubes as a new sorbent in dispersive micro solid-phase extraction to determine phenolic compounds

This report describes the use of trace-chitosan-wrapped multi-walled carbon nanotubes (CS-MWCNTs) as a sorbent material in dispersive micro solid-phase extraction (DMSPE), which was combined with ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry to analyze phenolic compounds in chrysanthemum tea and a chrysanthemum beverage. In this study, for the first time, CS-MWCNTs were used as a sorbent for this microextraction mode. Moreover, the proposed method exhibits the advantages of simplicity, rapidity, small sample amount and ease of operation. Furthermore, all of the important parameters that affect the extraction efficiency, such as the sorbent, pH, extraction time and type of elution solvent, were investigated and optimized in the DMSPE. Under the optimized extraction condition, the limit of detection, which was calculated based on a signal-to-noise ratio of 3, was 0.22-16.19 ng mL(-1). Satisfactory recovery values of 89-106% were obtained for the tested samples. The results show that the developed method was successfully applied to determine the content of chlorogenic acid and flavonoids in complex chrysanthemum samples. (C) 2015 Elsevier B.V. All rights reserved.