Ionic liquid mediated sol–gel sorbents for hollow fiber solid-phase microextraction of pesticide residues in water and hair samples

An ionic liquid mediated sol–gel sorbents for hollow fiber solid-phase microextraction (HF-SPME) was developed for extraction of the pesticides: diazinon, fenitrothion, malathion, fenvalerate, phosalone and tridemorph from human hair and water samples. The analytes were subsequently analyzed with high performance liquid chromatography and diode array detection (HPLC–DAD). Preliminary experiments were carried out in order to study experimental conditions for pesticides’ extraction from spiked hair and water samples with HF-SPME using hollow fiber-supported ionic liquid mediated sol–gel sorbent. The sol–gel nanocomposites were reinforced with nanoparticles such as carboxylic functionalized multi-walled carbon nanotubes (COOH-MWCNTs), amino functionalized multi-walled carbon nanotubes (NH2-MWCNTs), nano SiO2, nano TiO2 and nano MgO comparatively to promote extraction efficiency. In this device, the innovative solid sorbents were developed by the sol–gel method via the reaction of tetraethylorthosilicate (TEOS) with 2-amino-2-hydroxymethyl-propane-1,3-diol (TRIS). In the basic condition (pH 10–11), the gel growth process in the presence of ionic liquid and nanoparticles was initiated. Then, the sol was injected into a polypropylene hollow fiber segment for in situ gelation process. Parameters affecting the efficiency of HF-SPME were thoroughly investigated. Linearity was observed over a range of 0.01–25,000 ng/mL with detection limits between 0.004 and 0.095 ng/mL for the pesticides in the aqueous matrices and 0.003–0.080 ng/mL in the hair matrices. The relative recoveries in the real samples ranged from 82.0% to 94.0% for the pesticides store seller's hair and the work researchers’ hair. Results are showing the great possibilities of HF-SPME–HPLC-PDA for analysis of pesticides in biological and environmental samples.

► Determination of pesticides residue in hair samples.
► Ionic liquid mediated sol–gel sorbents.
► Hollow fiber solid phase microextraction.
► Disposable nature of the hollow fiber eliminates the possibility of sample carry-over.