Received: 31 October 2017 Revised: 2 December 2017 Accepted: 4 December 2017 DOI: 10.1002/sscp.201700016 RESEARCH ARTICLE Nanoporous silica aerogel modified by triethylchlorosilane as a new sorbent for the needle-trap extraction Ali Roostaie 1 Hasan Bargozin 2 Sirwan Mohammadiazar 3 Shokooh Ehteshami 4 1 Technology Management Department, Police Sciences and Social Studies Institute, Tehran, Iran 2 Department of Chemical Engineering, University of Zanjan, Zanjan, Iran 3 Department of Chemistry, Islamic Azad University, Sanandaj Branch, Sanandaj, Iran 4 Analytical Chemistry Laboratories, Department of Chemistry, Islamic Azad University, Central Tehran Branch, Tehran, Iran Correspondence Dr. Ali Roostaie Ph.D., Technology Management Department, Police Sciences and Social Studies Institute, Tehran, Iran. Email: ali.roostaie1@gmail.com In this work, nanoporous silica aerogel modified by triethylchlorosilane is used as a new sorbent for headspace needle-trap extraction of chlorobenzenes from aque- ous 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 tempera- ture, 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 lin- ear 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%. KEYWORDS chlorobenzenes, gas chromatography with mass spectrometry, modified nanoporous silica aerogels, needle-trap extraction, water samples 1 INTRODUCTION At the present time, chemical pollutants such as volatile organic compounds (VOCs) severely endangered for all liv- ing created. Recently, adsorbent materials such as zeolites, organic-inorganic hybrids, copolymers, resins and carbons were developed for this purpose [1]. The application of new sorbents based on silica materials for extracting organic com- pounds from aqueous solution such as forensic and biologi- cal sample were gained increasingly more attentions, because they have unique properties including high surface area and Abbreviations: APD, ambient pressure drying method; CB, chlorobenzene; HS, headspace; NTE, needle-trap extraction Conflict of interest: The authors have declared no conflict of interest. porosity, low thermal conductivity, low cost and high thermal stability [2–5]. The usual route for production of silica aerogels includes supercritical drying and the use of raw materials, such as tetraethoxysilane, which are obstacles to commercialization due to their prohibitive expense. For successful and cost effec- tive production of silica aerogels requirements include (1) the use of inexpensive precursors such as sodium silicate (water- glass) as a silica source, (2) the development of new surface modification methods that help in the ambient pressure drying method (APD) [6–8]. Aging of wet gels as a one step, which helps to better sur- face modification, is a very important step in silica aerogels synthesis. In this step the solid structure of gel is strength- ened with time and either the solvents such as alcohols can be Sep Sci plus 2017;1–7. © 2018 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim 1 www.sscp-journal.com