Model 5973 n msd mass spectrometer

The remaining procedures were carried out as previously reported [38 (link)] using an Agilent 6890 GC equipped with a 60 m × 0.25 mm i.d. DB-1 fused-silica capillary column (Agilent, Palo Alto, CA, USA) with a film thickness of 0.25 μm coupled to an Agilent model 5973 N MSD mass spectrometer. The injector temperature was maintained at 250 °C. The carrier gas (helium) flow rate was 1 mL/min. The electron energy was 70 eV at 230 °C. The derivatized phytosterol extracts were analyzed by GC using a 1:30 split ratio injection at 260 °C using hydrogen carrier gas. The initial column temperature was held at 50 °C for 0.5 min and then increased at a rate of 20 °C/min to 320 °C and held for a further 10 min with a flow of 1.4 mL/min. The 5α-cholesterol was taken as an internal standard. Aliquots of 2 μL of this solution were injected into the gas chromatograph, and the ratio of the peak areas of the analyte and internal standard was used as an analytical signal.

The volatile compounds were identified using an Agilent 6890 GC equipped with a 60 m × 0.25 mm i.d. DB-1 fused-silica capillary column (Agilent, Palo Alto, CA, USA) with a film thickness of 0.25 μm coupled to an Agilent model 5973 N MSD mass spectrometer The injector temperature was maintained at 250 °C. The split ratio was set at 50:1. The initial temperature was set at 40 °C for 10 min, then programmed at 2 °C/min up to 240 °C, and held at this temperature for 20 min. The carrier gas (helium) flow rate was 1 mL/min. The electron energy was 70 eV at 230 °C. The constituents were identified by matching their spectra with those recorded in a mass spectral library (Wiley 7n). In addition, the constituents were confirmed by comparing the Kovats indices or GC retention time data with those of authentic standards or those in the published literature. The linear RIs were calculated from the retention times of n-alkanes (C₅–C₂₅) that were run under the same chromatographic conditions. Volatile compound of chromatography results expressed as area percentages were calculated (response factor: 1).