HRGC-HRMS Analysis of Environmental Samples

In this study, we used the chromatographic conditions stated in Santos et al.^{45 (link)} Briefly describing, we utilized a high-resolution gas chromatograph-high-resolution mass spectrometer detector (HRGC-HRMS) from Shimadzu (GCMS-QP2010Plus, Shimadzu, Japan) with a Rtx-5MS gas capillary column (30 m × 0.250 mm × 0.25 µm, Restek Bellofonte, USA). Oven temperature programing initiated at 70 °C (2 min), then rising from 70–200 °C (30 °C min⁻¹, 5 min), and 200–330 °C (5 °C min⁻¹, 0.67 min). Injector temperature was set at 310 °C and transfer line was 280 °C. Analysis was done in GC-MS-SIM, at electron impact mode (EI) (70 eV). Sample preparation was done using a filter piece of 4.15 cm² diameter added to a miniaturized micro-extraction device using 500 µL solvent extraction^{45 (link),61 (link)}. Sample preparation details are found in Supplementary Information.