Ordered nanoporous carbon as an effective adsorbent in solid-phase microextraction of toluene and chlorinated toluenes in water samples

Ordered nanoporous carbon (CMK-3) has been synthesized and immobilized onto a copper wire, and subsequently applied to headspace solid phase microextraction (HS-SPME) of toluene, 4-chlorotoluene, 2,4-dichlorotoluene and 2,6-dichlorotoluene following gas chromatographyflame ionization detection (GC-FID). The structural order and textural properties of the prepared materials have been characterized by N-2 sorption analyses, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Five experimental parameters such as extraction temperature, extraction time, salt concentration and stirring speed have been evaluated and optimized by means of a Taguchi's OA(16)(4(5)) orthogonal array experimental design. The experimental results indicate that extraction temperature and extraction time are the most significant factors in the analysis procedure. The optimum extraction conditions were as follows: 12 mL sample volume; ambient temperature; 10% (w/v) NaCl; 35 min extraction time and stirring rate of 600 rpm. Under the optimized conditions for all analyzed compounds, the linearity was from 2.5 to 400 mu g L-1, and limit of detections (LODs) were between 0.02 and 0.08 mu g L-1. The relative standard deviation values were <= 5.25% and recovery values were between 85.60% and 104.12%. This method has been successfully used for preconcentration and analysis of above mentioned compounds in different real water samples. (C) 2012 Production and hosting by Elsevier B.V. on behalf of King Saud University.