On-site trihalomethanes extraction from water using 3D printing solid phase extraction device and analysis by GC-ECD

A 3D-printed device coated with SDB-1 resin was developed for on-site extraction and preconcentration of trihalomethanes (THMs) and subsequent determination by gas chromatography (GC) with an electron capture detector (ECD). This device was fabricated by stereolithography and covered with a commercial SPE resin using the stick & cure immobilization technique. Various parameters that affect extraction efficiency and preconcentration (resin type, conditioning mode, extraction modality, extraction time, and eluent volume) were optimized using four THMs (Chloroform, TCM; Bromodichloromethane, BDCM; Dibromochloromethane, DBCM; and Tribromomethane, TBM) and an internal standard (1,2-dibromopropane). Under the optimized conditions, good linearity for THMs studied were obtained in a range of 0.25–100 µg L⁻¹ with r ≥ 0.998 and limits of detection between 0.02–0.05 µg L⁻¹. The precision expressed as relative standard deviation (%RSD, n = 3), showed intraday and interday ranges of 1.8–4.2 % and 3.3–9.4 %, respectively, demonstrating a good precision of the proposed methodology. The proposed method was successfully applied to the simultaneous analysis of four THMs in wastewater effluent and tap water samples, revealing total concentrations of 34.1 and 78.1 µg L⁻¹, respectively. This user-friendly and miniaturized device features a simple extraction procedure (up to 24-fold enrichment), with excellent sensitivity and precision, which is very useful and practical for the simultaneous analysis of volatile compounds. Additionally, three greenness evaluation methodologies (AGREE, AGREEprep, and GAPI) and a practicality tool (BAGI) were employed to assess the environmental friendliness and applicability of the proposed method, demonstrating its superior performance compared to previously reported GC methods in the literature.