Vol.:(0123456789) 1 3 Bulletin of Environmental Contamination and Toxicology https://doi.org/10.1007/s00128-019-02567-4 Extraction and Trace Analysis of Trihalomethanes in Water Samples Using Zein@Fe 3 O 4 Nanocomposite Fatemeh Hajilari 1  · Khalil Farhadi 2  · Habibollah Eskandari 1 Received: 10 January 2019 / Accepted: 1 February 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract This study presents a simple dispersive solid phase extraction (DSPE) technique combined with headspace thermal desorp- tion (HSTD) for extraction and determination of the most signifcant trihalomethanes (THMs), bromodichloromethane, bromoform, chloroform and dibromochloromethane, in water samples by using Zein@Fe 3 O 4 nanocomposite coupled with gas chromatography/micro electron capture detection (GC–MECD). Various parameters afecting the DSPE-HSTD performance were investigated and optimized. The obtained results revealed that under optimum conditions, LOD and LOQ values were in the range of 0.1–0.36, 0.3–1.08 µg L −1 , respectively. The intra-day and inter-day precisions of the method at a concentra- tion of 10 µg L −1 for each analyte (n = 5) were obtained in the range of 5.69–6.70% and 6.12–7.34%, respectively. Finally, the proposed method was successfully applied for extraction and determination of four THMs in drinking water samples. Keywords Trihalomethnes · Zein@Fe 3 O 4 nanocomposite · Dispersive solid phase extraction · Biopolymer · Gas chromatography · Environmental analysis Trihalomethanes (THMs) as an important group of disin- fection byproducts (DBPs) are formed by the reaction of chlorine with natural organic matter exists in water supplies. THM levels tend to increase with increasing pH, tempera- ture, time, inorganic species and humic acid concentration (WHO 2005). Ingestion of drinking water and food as well as inhalation and dermal contact are considered as the most important ways for human exposure to these compounds (THMs) (WHO 2011). According to the classifcation of the International Agency for Research on Cancer (IARC), chloroform (CF) and bromodichloromethane (DBCM) and recently iodinated DBPs (I-DBPs) (even at very low concen- trations) are possibly carcinogenic to humans (Group 2B). Additionally, exposure to THMs for a long time can increase bladder cancer risk (McGeehin et al. 1993), spontaneous abortion (Waller et al. 1998), and birth defects (Bove et al. 1995; Wang et al. 2007). The US Environmental Protection Agency (EPA) has published the “Stage 1 Disinfectants and Disinfection Byproducts Rule” to regulate total trihalometh- anes (TTHM) at a maximum allowable annual average level of 80 µg L −1 (EPA 2001); the European Union has estab- lished maximum guideline values at 100 µg L −1 for the total of THMs in drinking water (EU 2014). In last decade, a few methods for the determination of THMs in water samples have been addressed in literature. The most widely used technique for determination of THMs concentration in wtare samples is based on gas chromatog- raphy coupled with various detectors including mass spec- trometer and electron capture. Due to limitations for direct injection of aqueous samples onto gas chromatography col- umn as well as the trace levels of THMs in diferent water samples, an extraction/preconcentration step is required for selective extraction of THMs. Several approaches such as liquid–liquid extraction (LLE), solid phase extraction, solid phase microextraction (SPME), hollow fber liquid phase microextraction (HFLPME), and headspace solid phase extraction (HS-SPE) have been reported for this purpose (Liu et al. 2013; Franco et al. 2018; Domínguez-Tello et al. 2015; Allard et al. 2012; Merib et al. 2013; Lourencetti et al. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00128-019-02567-4) contains supplementary material, which is available to authorized users. * Khalil Farhadi khalil.farhadi@yahoo.com; kh.farhadi@urmia.ac.ir 1 Department of Chemistry, University of Mohaghegh Ardabili, Ardabil, Iran 2 Department of Analytical Chemistry, Faculty of Chemistry, Urmia University, Urmia, Iran