7890a series gc

Methanol extract was prepared (1 mg/mL), the methanol vaporized and subsequently was added 50 μL of derivatizing agent, BSTFA (N,O-bis [trimethylsilyl] trifluoroacetamide) + 1% TMCS (trimethylchlorosilane), and agitated for 2 min at room temperature. Finally, sample (1 μL) was inserted at a GC–MS system (Agilent GC Series 7890A and an Agilent single quadrupole MS detector Agilent model 5975C)), with electron impact model (70 eV) and the mass range at 50–700 m/z. The separation was performed on an HP-5MS capillary column (30 m × 0.25 mm i.d. × 0.25 μm) and splitless injector (at 250 °C) was used to 2.5 min/splitless time. The initial oven temperature was kept at 100 °C for 1 min and raised to 220 °C at 6 °C/min, and kept constant for 1.23 min, afterward raised to 290 °C at 10 °C/min, and raised to 310 °C at 40 °C/min, and kept constant for 7.5 min. The carrier gas (helium) flow rate was maintained at 1 mL/min. The GC–MS control and data processing was identified by comparing their mass spectra using Chem-Station (Agilent Technologies, DEU) software. Metabolite identifications was analyzed the spectral (MS) matching with commercialized libraries (NIST) based upon retention time, m/z, and percentage of spectral similarity greater than 60% and the internal standard.

GC-MS analysis was carried out as accomplished by Lim et al. [31 (link)] with some modifications. The supernatants of the sample were prepared with the solvent and derivatized and subsequently were taken, and 1 μL of the sample was injected in triplicate in an Agilent gas chromatograph (GC) series 7890A (Wilmington, DE) coupled to a single quadrupole mass spectrometer (MS) detector (Agilent 5975C) equipped with an electron impact (EI) ionization source. The carrier gas (helium) flow rate was maintained at 1 mL min⁻¹. The injector temperature was set at 250 °C in splitless mode. An HP-88 capillary column (30 m × 0.25 mm inner diameter × 0.25 μm) was used. The initial oven temperature was 50 °C, held for 1 min, and raised to 175 °C at 15 °C min⁻¹, then raised to 240 °C at 1 °C min⁻¹, and held for 5 min. EI energy was set at 70 eV, and the mass range was set at m/z 50−1100. FAMEs were identified and quantified by comparison with a standard Supelco 37 Component FAME Mix, and data processing was performed using ChemStation (Agilent Technologies) software.

Each sample was prepared in methanol HPLC (1 mg/mL). Methanol was evaporated with nitrogen gas, and 50 μL of derivatizing agent, BSTFA (N,O-bis[trimethylsilyl]trifluoroacetamide, CAS 2561-30-2, Merck KGaA, Darmstadt, Germany) + 1% TMCS (trimethylchlorosilane) (CAS 75-77-4, Wacker Chemie AG, Burghausen, Germany ) was added. The solution was stirred for 2 min at room temperature, and 1 μL of the sample was injected in triplicate in an Agilent gas chromatograph (GC) series 7890A coupled to a single quadrupole mass spectrometer (MS) detector (model 5975C, Agilent Technologies, Waldbronn, Germany) equipped with an electron impact (EI) ionization source. The cattier gas (helium) flow rate was maintained at 1 mL min-1. The injector temperature was set at 250 °C in splitless mode. An HP-5MS capillary column (30 m length, 250 μm of inner diameter, and 0.25 μm of film thickness) was used. The initial oven temperature was 100 °C for 1 min, rising to 220 °C at 6 °C/min, and maintained for 1.23 min. Then, the temperature was increased to 290 °C at 10 °C/min, and finally raised to 310 °C at 40 °C/min, and maintained for 7.5 min. El energy was set at 70 eV, and the mass range was set at m/z 50 to 700. GC-MS control and data processing were performed with the Chem-Station (Agilent Technologies, Waldbronn, Germany) software version C.01.10.