Headspace solid phase microextraction of volatile aromatic hydrocarbons using a steel wire coated with an electrochemically prepared nanocomposite consisting of polypyrrole, carbon nanotubes, and titanium oxide

We have prepared a new material for solid-phase microextraction (SPME) of volatile aromatic hydrocarbons by electropolymerization of pyrrole, carbon nanotubes, and titanium oxide on the surface of a stainless steel wire. This fiber-like wire was used for the headspace solid-phase microextraction of mixtures of benzene, toluene, ethylbenzene, and o-xylene (BTEX), followed by their quantitation by GC with FID detection. The fiber is easily prepared, robust, thermally stable, and has good extraction efficiency. Under optimal conditions, the detection limits (at an SNR of 3) are in the range from 0.01 to 0.04 ng mL−1, and the limits of quantification (at an SNR of 10) are between 0.03 and 0.09 ng mL−1. The relative standard deviations (RSDs) for one fiber (i. e. the repeatability; for n = 5) range from 3.5 to 5.6 %, while the RSDs between fibers or from batch to batch (i.e. the reproducibility; for n = 3) are in the range from 5.9 to 8.1 %. The method was successfully applied to (spiked) real water samples, the relative recovery percentages being between 93.7 and 106.2 %.