Nanoporous silica aerogel modified by triethylchlorosilane as a new sorbent for the needle‐trap extraction

In this work, nanoporous silica aerogel modified by triethylchlorosilane is used as a new sorbent for headspace needle‐trap extraction of chlorobenzenes from aqueous samples. The needle trap extraction is derived from solid‐phase microextraction, and the sorbent is in the inside a needle. The thermal stability and functional groups of the sorbent were studied by thermal gravimetric/differential thermal analyses and FTIR spectroscopy, respectively. The modified silica aerogel characterized by field‐emission scanning electron microscopy shows a 3D network containing homogeneous pore structure with pore sizes of a few tens of nm and a nanoporous structure. The influential parameters on the extraction efficiency, including the extraction temperature, ionic strength and extraction time, were optimized. Under optimized conditions, the detection limit and quantification limit were obtained in the range of 0.3–1 and 1–3 ng/L, respectively. The relative standard deviation values for water spiked with the chlorobenzenes at 100 ng/L under optimum conditions were 3–9%. The dynamic linear range of method was investigated in the range of 3–3000 ng/L. Finally, the current method for the analysis of real water samples containing spiked chlorobenzenes was applied and the relative recovery values were found to be in the range of 96–101%.