A non-ionic surfactant-mediated sol–gel coating for solid-phase microextraction of benzene, toluene, ethylbenzene and o-xylene in water samples using a gas chromatography-flame ionization detector

Abstract

In this study, sol–gel hybrid organic–inorganic materials were prepared in the presence of polyethyleneoxide (PEO) non-ionic surfactants (Triton X-100), which act as co-porogenic agents. For the first time, non-ionic surfactant mediated sol–gel coatings were evaluated by analyzing benzene, toluene, ethylbenzene and o-xylene (BTEX) in the aqueous samples. Two different fiber coatings were prepared including: un-modified poly(dimethylsiloxane) (PDMS) coating prepared from PDMS in the absence of Triton X-100 as a non-ionic surfactant (PDMS-no TX100), and modified PDMS coating prepared from this polymer in the presence of Triton X-100 as a porogenic agent and conditioned at a higher temperature than decomposition temperature of a non-ionic surfactant (PDMS-TX100). After the analytical procedure was optimized, the dynamic linear range obtained using PDMS-TX100 and PDMS-no TX100 fibers was 4–200 000 and 100–200 000 pg mL⁻¹ and the limits of detection (S/N = 3) were 1–3 and 30–300 pg mL⁻¹, respectively. The relative standard deviations (RSDs) for one fiber (repeatability) (n = 5) were from 3.1 up to 6.2% and between fibers or batch to batch (reproducibility) (n = 3) in the range of 4.2–7.7% for three fibers. The developed method was successfully applied to the real water samples while the relative recovery percentages obtained for the spiked water samples at 20 pg mL⁻¹ of each analyte were from 94.41 to 104.05%.