Scion 436 ms

Samples were prepared as described for LC-HRMS/MS analysis, a 50 µL aliquot was freeze-dried and solubilized in 50 µL ethyl acetate for GC-TQ-MS/MS analysis. Gas chromatography (GC) was performed on a triple quadrupole detector (TQ, SCION 436-MS, Bruker) in multiple reaction monitoring (MRM) mode to obtain fragmentation of the compounds (MS/MS) as already described by ref. ⁵⁹ . A Rxi®−5Sil MS column (Restek, 30 m, 0.25 mm ID, 0.25 µm) was used, with a constant flow of helium gas (1 mL/min, Alphagaz 2, Air Liquide). The injector was operated at 280 °C with a pressure pulse at 30 psi, the oven was set at 70 °C for 0.7 min and the temperature was increased to 180 °C at 30 °C/min and then to 300 °C at 10 °C/min, with a stabilization time of 2 min. The electron impact energy for fragmentation was 70 eV, and 328 POPs (pesticides, toxicants, and polycyclic aromatic hydrocarbons) were targeted. At least two daughter ions were recorded for each analyte, and a retention window of 5 min was used. Analytical quality checks were performed using a mix of pesticides to assess the retention times (ref 32563, Restek).