Development and application of a new solid-phase microextraction fiber by sol-gel technology on titanium wire

Novel solid-phase microextraction fibers were prepared based on sol-gel technique. Commonly used fused silica substrate was replaced by titanium wire which provided high strength and longer fiber life cycle. Titanium isopropoxide was employed as the precursor which provides a sol solution containing Ti-OH groups and shows more tendencies to the molecularly similar group on the substrate. Three different polymers, poly (dimethylsiloxane) (PDMS), poly(ethylenepropyleneglycol)-monobutyl ether (Ucon) and polyethylene glycol (PEG) were employed as coating polymer in preparing three different fibers. The applicability of these fibers was assessed for the headspace SPME (HS-SPME) of benzene, toluene, ethylbenzene and xylenes (BTEX) from water sample followed by gas chromatography-mass spectrometry (GC-MS). Effects of different parameters such as fiber coating type, extraction condition, desorption condition were investigated and optimized. Under the optimized conditions, LODs and LOQs of 0.75-10 mu g L-1 (S/N = 3) and 1-20 mu g L-1 (S/N = 10) were respectively obtained. The method showed linearity in the range of 10-25,000 mu g L-1 with correlation coefficient of >0.99. The relative standard deviation was less than 8%. (C) 2012 Elsevier B.V. All rights reserved.