Green trapping intra tube flux extraction device using polymethyl methacrylate for organochlorine pesticide analysis by gas chromatography-mass spectrometry

In chemical analysis, sample preparation is the most time-consuming and error-prone step. Available routine methods such as SPE and SPME are usually laborious, expensive, and fragile. For instance, the highly sensitive SPME fibers can break with even a tiny error, rendering them unusable. In this paper, the use of Poly(methyl methacrylate) (PMMA) as the extraction phase in Intra Tube Flux extraction (IT-FEx-SPME) is presented as a one-step, environmentally friendly, and solvent-free method of aqueous sample preparation for gas chromatography. After the extraction of the analytes, the device is inserted into the gas chromatograph (GC) injector for thermal desorption and chromatographic separation. Different molar masses of the PMMA extraction phase for coating the device were also investigated, specifically 120,000 g mol⁻¹ and 350,000 g mol⁻¹; the denser one was more thermally stable in the long term. The method was optimized and validated for analyzing five organochlorine pesticides - heptachlor, aldrin, heptachlor epoxide, endosulfan, and dieldrin. LOD from 0.21 to 1.63 ng mL⁻¹ and LOQ from 0.92 to 7.22 ng mL⁻¹ were achieved. Repeatability within one day (n = 5) resulted in RSD values of 6.09 % to 23.28 %. Inter-day reproducibility (n = 10) showed RSD values ranging from 12.94 % to 19.33 %. The recovery values ranged from 93.07 % to 100.32 %. The method offers a feasible, cost-effective, rapid, green, and safe alternative for the routine analysis of organochlorine pesticides in aqueous samples using GC.