Highly porous nanostructured copper oxide foam fiber as a sorbent for head space solid-phase microextraction of BTEX from aqueous solutions

A highly porous copper foam was constructed on the surface of an unbreakable copper wire by a very rapid electrochemical method. Then, the copper oxide arrays were constructed on the pore surface of the copper foam by the thermal process. The applicability of the fiber was examined for the head space SPME (HS-SPME) of benzene, toluene, ethylbenzene and xylene (BTEX) in different water samples followed by gas chromatography-flame ionization detection. A Plackett-Burman design was performed for screening the experimental factors to determine significant factors influencing method extraction efficiency. The effective factors were then optimized using Box-Behnken Design (BBD). Compared with the bare copper foam coating, copper oxide fiber has extraction ability for the target analytes, which is comparable with the extraction efficiencies obtained from commercial polydimethylsiloxane (PDMS) fiber with 100 pm thicknesses. Under optimum conditions, the developed method exhibited low limits of detection (0.12-0.41 mu g L-1), low limit of quantification (0.40-1.36 mu g L-1), wide linear range (1-500 mu g L-1) with coefficient of determination > 0.99, good relative standard deviations (6.9-9.6%) and good recoveries (higher than 88%), which confirm the capability of the prepared fibers in analysis of BTEX.