Using nanometer TiO₂ modified with cetyl trimethyl ammonium bromide for separation and preconcentration of Parathion in water sample

In this work, nanometer TiO₂ modified by cetyl trimethyl ammonium bromide (CTAB) was used as adsorbent for solid-phase extraction (SPE) of Parathion in environmental water samples. Adsorbed Parathion was then desorbed with different eluents and determined by gas chromatography (GC)/flame ionization detection. Greater selectivity, resolution, and sensitivity have been seen by GC compared with other methods. Parameters that might influence the extraction efficiency, such as the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate, were optimized. Under the optimized extraction conditions with toluene as the eluent, the experimental results showed the excellent linearity of Parathion (R² > 0.99) over the range of 0.01–0.8 μg/mL, and the relative standard deviation was 6.3% (n = 5). The detection limit of the proposed method could reach 0.024 ng/mL based on the ratio of chromatographic signal to base line noise (S/N = 3). Recovery of 93% was achieved with spiked water samples. The method was successfully applied to the analysis of surface water samples.