5977a mass selective detector

Chromatographic analysis using GC-MS was carried out (Agilent Technologies 7890B GC Systems combined with 5977A Mass Selective Detector). Capillary column (HP-5MS Capillary; 30.0m×0.25mm ID×0.25μm film) and helium as carrier gas were used at a rate of flow of 1.9 ml/min with 1μl injection. The sample was analyzed with the column held initially for 3 min at 40°C after injection, then the temperature was increased to 300°C with a 20°C/min heating ramp, with a 4.0 min hold. Injection was carried out in split-less mode at 300°C. MS scan range was (m/z): 50–550 atomic mass units (AMU) under electron impact (EI) ionization (70 eV).

GC-MS of Salvia essential oils was carried out using an Agilent 7890 B gas chromatograph (Agilent Technologies, Rotterdam, The Netherlands). The column used was a VF-Wax CP 9205 fused silica (30 m × 0.25 mm, ID 0.25 µm). Helium was used as carrier gas at a flow rate of 0.9 mL/min. An Agilent 5977A mass selective detector was used, with a scan range of 45–950 atomic mass units with a detector temperature of 270 °C and split mode injection at a split ratio of 1:20. An autosampler was used for sample injection (0.5 µL) with an injector temperature of 250 °C. The interface temperature was 280 °C, the source temperature was 230 °C, and the ionization energy was 70 eV. The initial oven temperature was 50 °C for 5 min., which was then raised to 280 °C at a rate of 5 °C/min, then kept isothermal at 280 °C for 15 min. Standard alkanes (C7-C40) obtained from Sigma-Aldrich (Darmstadt, Germany) were used to calculate the Kovats index (KI). Chromatograms were generated using enhanced ChemStation software (Agilent Technologies, Waldbronn, Germany). Volatile compounds were identified by comparing their mass spectra and KI was calculated with the 9th edition of Wiley Registry of mass spectral data and NIST library.

GC-MS analysis was performed using a HP 7890B gas chromatograph (Agilent Technologies, Santa Clara, CA, USA) coupled with a 5977A mass selective detector (MSD) (Agilent Technologies) and a multi-purpose sampler MPS 2 (Gerstel, Mülheim an der Ruhr, Germany). HP-innowax fused silica capillary column (30 m length × 0.25 mm internal diameter × 0.25 μm film thickness; Agilent Technologies) was used with helium, a carrier gas, at a constant flow rate of 1 mL/min. Injection volume was 1.0 μL with split mode (20:1). The oven temperature program started at 40 °C initially and was held for 3 min, then was raised to 200 °C at 5 °C/min and held at 200 °C for 3 min. Post run was held at 180 °C for 2 min. Inlet, detector transfer line and mass source temperatures were 250, 280, 230 °C, respectively. MS was operated in the electron impact (EI) ion source mode at 70 eV with a scan range of 25~350 a.m.u. Ethanol (>99.9%) was purchased from Sigma-Aldrich (Sigma-Aldrich, St. Louis, MO, USA) for standard preparation. 4-Methyl-1-pentanol, an internal standard (ISTD) compound, was also obtained from Sigma-Aldrich. dl-alanine and dl-proline were purchased from Sigma-Aldrich and Oasis MAX cartridge 6 cc with stationary phase was purchased from Waters (Waters, Milford, MA, USA).

The GC-MS characterization of volatile components was performed on an Agilent 7890 B gas chromatograph (Agilent Technologies, Rotterdam, The Netherlands) equipped with a VF-Wax CP 9205 fused silica column (100% polyethylene glycol, 30 m × 0.25 mm, 0.25 µm). It was coupled with a 5977A mass selective detector (Agilent Technologies). The interface temperature: 280 °C; MS source temperature: 230 °C; ionization energy: 70 eV; scan range: 45–950 atomic mass units. The sample (0.5 μL) was automatically injected into the chromatograph using a GC auto sampler. The oven temperature was kept at 50 °C for 5 min, then rising from 50 °C to 280 °C at 5 °C/min, and was finally held isothermally at 280 °C for 15 min; injector temperature 250 °C; detector temperature 270 °C; carrier gas helium (0.9 mL/min); with split mode (split ratio, 1:20). C7–C40 standard saturated alkanes were purchased from Sigma-Aldrich (Merck, Germany). Enhanced ChemStation software, version MSD F.01.01.2317 (Agilent Technologies) was used for recording and integrating the chromatograms. The compounds were identified by comparison of their mass-spectral data and retention indices (RIs) with those of the Wiley Registry of Mass Spectral Data (9th Ed.), NIST Mass Spectral Library (2011), references [48 ,49 (link)] and our own laboratory database [50 (link)].

We employed the Agilent Technologies 7890B (GC) machinery equipped with 5977A Mass Selective Detector (MS), HP-5MS (5% phenyl methyl siloxane) capillary column of dimensions 30m×250μm×0.25μm and used helium as the carrier gas at 1 mL/min. For the original sample, the column temperature was programmed initially at 40°C for 3min, followed by an increase of 10°C /min to 220°C and then an increase of 25°C /min to 280°C. For the baked sample, the column temperature was programmed initially at 40°C for 5min, followed by an increase of 10°C /min to 180°C and then an increase of 20°C /min to 280°C. The MS was operated at 70eV. The constituents were identified by comparison of their mass spectral data with those from NIST 11 Spectral Library.

FA composition was measured by a modified gas chromatography-mass spectrometry (GC-MS) method, as previously described [48 (link)]. Briefly, total lipids were extracted from plasma with a mixture of methyl-tert-butyl ether (MTBE), methanol and water [49 (link)]. For liver, pulverized tissues (25mg) were incubated overnight at 4°C in a solution of chloroform/methanol (2:1) containing 0.004% butylated hydroxytoluene (BHT), filtered through gauze and dried under nitrogen gas. Plasma and liver FA were analyzed as their fatty acid methyl derivatives (FAME) after direct transesterification with acetyl chloride/methanol [50 (link)]. Injections (2 μL for plasma and 1 μL for liver samples) were performed onto an Agilent 7890B gas chromatograph equipped with a Select FAME CP7420 capillary column (100 m; 250 μm inner diameter; 230 μm thickness) coupled with a 5977A Mass Selective Detector operated in positive chemical ionisation mode using ammonia as reagent gas. FA were identified according to their retention time and m/z, and their concentration was calculated using a mix of internal and external labelled standards added to liver and plasma samples at known concentrations. The concentration of arachidonic acid, calculated using its [²H₈]-labeled counterpart as internal standard, is reported as absolute concentration (μM or nmol/mg tissue) and relative to total fatty acid content (%).