Zb 5ms plus column

Ten replicates of each experimental condition, including samples exposed to Ch-SeNPs and untreated controls, were subjected to analysis using a gas chromatograph (7890A Agilent, Santa Clara, CA, USA) coupled to a high-resolution time-of-flight mass spectrometer (GCT Premier Micromass Waters, Waters Corporation, Milford, MA, USA).
During the analysis, a 2 μL volume of the samples was injected in split mode at a 1:3 ratio. Metabolite separation was achieved using a ZB-5MS plus column (30 m, 0.25 mm × 0.25 μm; Phenomenex, Alcobendas, Spain) at a flow rate of 1 mL/min, with He serving as the carrier gas. The column temperature was initially set at 60 °C for 3 min, and then it was gradually increased at a rate of 6 °C/min until reaching 325 °C, where it was held for 3 min. The inlet temperature was maintained at 270 °C, and a solvent delay of 2.5 min was employed.
The mass spectrometer was equipped with an electron-ionization (EI) ion source, and it recorded spectra within a mass range of from 50 to 800 m/z. To monitor the performance of the analysis, a GC-column test standard (Phenomenex, Alcobendas, Spain) was included and analyzed every 5 samples as a quality-control measure.

The analysis of the LE by GC–MS was carried out at the mass spectrometry research support center at the Complutense University of Madrid (Spain) following a standard method. Briefly, samples were dried under nitrogen and derivatized with 60 μL of N,O-Bis(trimethylsilyl)trifluoroacetamide and trimethylchlorosilane (BSTFA: TMSC; 99:1). Then, the derivatized samples were analyzed on a Varian CP3800 GC system (Varian Inc., United States) with a ZB-5MS plus column (Phenomenex Inc., 30 m × 0.25 mm × 0.25 μm) coupled to a Saturn 2200 ion trap mass spectrometer (Varian Inc., Palo Alto, CA, USA), using helium as the starting mobile phase at 60 °C, gradually increasing to 220 °C at 16 min, and to 320 °C at 5 min, with 320 °C held for 6 min. The injection volume was 2 μL and the flow rate was set up to 1 mL/min. Compounds were identified by searching against the NIST library and considering an R-Match higher than 700.