One-pot synthesis of ethylenediamine-connected graphene/carbon nanotube composite material for isolation of clenbuterol from pork

A fluffy porous ethylenediamine-connected graphene/carbon nanotube composite (EGC), prepared by a simple and time-saving one-pot synthesis, was successfully applied as an adsorbent in pipette-tip solid-phase extraction (PT-SPE) for the rapid extraction and determination of clenbuterol (CLB) from pork. In the one-pot synthesis, carbon nanotubes were inserted into graphene sheets and then connected with ethylenediamine through chemical modification to form a three-dimensional framework structure to prevent agglomeration of the graphene sheets. Under the optimum conditions for extraction and determination, good linearity was achieved for CLB in the range of 15.0-1000.0 ng g(-1) (r = 0.9998) and the recoveries at three spiked levels were in the range of 92.2-96.2% with relative standard deviation <9.2% (n = 3). In comparison with other adsorbents, including silica, NH2, C-18, and Al2O3, EGC showed higher extraction and purification efficiency for CLB from pork samples. This analytical method combines excellent adsorption performance of EGC and high extraction efficiency of PT-SPE. (C) 2017 Elsevier Ltd. All rights reserved.