Rtx 5ms column

The GM-MS method was used to conduct a qualitative and quantitative characterization of neem extract, using the model (GC–MS-QP2010-Ultra) from Shimadzu Company, Japan, with a capillary column Rtx®-5MS column (30 m, 0.25 mm, 0.25 µm) [64 (link)]. The split mode was used for sample injection, and operated in electron ionization (EI) mode at 70 eV, inflow rate of 1.69 ml/min. Helium gas was used as carrier gas. The injector temperature was set at 300 °C, the temperature of the ion source was 200 °C, and 250 °C was used as interface temperature. The oven temperature program was as follows: the initial temperature at 50 °C rising at 7 °C /min to 180 °C, then the rate changed 10 °C/min reaching the final temperature at 280 °C with 2 min as hold time. In a total 22 min run, the sample was analyzed by the scan mode in a range of 40 to 500 m/z charges to ratio. The neem extract's components were identified by comparing the retention times and mass fragmentation patents with the National Institute of Standards and Technology (NIST) library, and then the results were recorded [65 , 66 (link)].

The mass spectra were recorded with a Shimadzu GCMS-QP2010 (Tokyo, Japan) equipped with a split–splitless injector and Rtx-5MS column (30 m × 0.25 mm i.d. × 0.25 µm film thickness) (Restek, Bellefonte, PA, USA). The capillary column was attached to a quadrupole mass spectrometer (SSQ 7000; Thermo-Finnigan, Bremen, Germany). The initial temperature of the column was set to 45 °C for 2 min and programmed to 300 °C at a rate of 5 °C/min; then, it was kept constant at 300 °C for 5 min. The injector temperature was 250 °C. The flow rate of the carrier gas (helium) was 1.41 mL/min. The mass spectra were recorded according to the following conditions: filament emission current (equipment current), 60 mA; ionization voltage, 70 eV; ion source, 200 °C. Diluted samples (1% v/v) were injected via the split mode (split ratio: 1:15) [33 (link)].

The chemical composition and characterization of the bio-active compounds from the essential oil of AALEO was analyzed by gas chromatography (GC) and GC-mass spectrometry (GC-MS) using a SHIMADZU QP2010 with a RTX5 MS column (30 m, film 0.25 μm, ID 0.25 mm). The temperature of the column was programmed from 45 to 270°C at 5°C min^-1, the injector and detector temperatures for the analysis were 250°C. Helium was used as the carrier gas at a flow rate of 1.5 ml min^-1. The identification of chemical constituents was performed on the basis of retention indices (RI) determined with reference to a homologous series of n-alkanes, under identical experimental conditions, co-injected with standards (RESTEK, 110 Benner Circle, Bellefonte, PA, USA), followed by MS library search (WILEY8.LIB and NIST08.LIB Version; Mdoe et al., 2014 (link)).

Analyses of the fatty acid composition of C. elegans were done as described previously (Watts and Browse, 2002 (link)). Briefly, 200 adult C. elegans were collected with M9 buffer and washed three times. After centrifugation, M9 buffer was removed with a pipette and replaced with 1 mL 2.5% H₂SO₄ in methanol to extract fatty acids from tissues and then to carry out their transmethylation. Samples were capped and incubated for 1 h at 80°C. After the addition of 0.2 mL hexane and 1.5 mL water, fatty acid methyl esters were extracted into the hexane layer by shaking and centrifugation of the tubes at low speed. Aliquots (1 μL) of the organic phase were analyzed by GC using a gas chromatograph (QP2010 series; Shimadzu, Kyoto, Japan) equipped with a RTX-5MS column (30 × 0.25 mm). Mass conditions: EI source (70 ev), dual-filament, scanning range (50–500 m/z), scan interval 1.0 s. Helium was the carrier gas (injected at 1.4 mL/min), and a flame ionization detector was employed. The gas chromatograph was programmed at an initial temperature of 120°C for 1 min, followed by an increase of 10°C/min to 190°C, followed by an increase of 2°C/min to 200°C. The mass spectra of the peaks identified as palmitic acid, palmitoleic acid, oleic acid, and stearic acid matched the spectra presented by W. W. Christie on the lipid library website¹.

The asymmetric epoxidation of alkenes over the Ti-Beta-TEAOH and normal Ti-Beta was carried out under the following conditions: 0.2 g catalyst, 10 mL acetonitrile, substrate/H₂O₂ (35% in aqueous solution) = 1, 70 °C, 2 h. The products were identified by a Shimadzu GCMS-QP 2010 Ultra instrument equipped with a Rtx-5MS column and/or comparing with standard (2S,3S) and (2R,3R)-epoxide. Enantioselectivities were determined by chiral GC (Shimadzu, GC-2010 Plus) equipped with a CP-Chirasil-Dex CB column.

To analyze the compounds in KD5040, we performed GC, equipped with an Rtx-5 ms column (30 m × 0.25 mm × 0.25 μm) and a mass spectrometer (GCMS-QP5000 series; Shimadzu, Japan). The carrier gas was hydrogen at a flow rate of 3 mL/min. The column temperature was initially at 40 °C for 1 min, then increased gradually to 300 °C at 10 °C/min. Extracts were diluted 1:10 (v/v) with ethanol, and 1 μL of the diluted samples was injected automatically in split mode. Injector and detector temperatures were set at 230 °C and 280 °C, respectively.

The chemical composition of the essential fennel oil was determined by gas chromatography-mass spectrometry system (GC-MS-QP 2010, Shimadzu, Japan), equipped with a flame-ionization detector (FID) with a Rtx-5MS column (30 m × 0.25 mm, 0.25 μm thickness). The essential oil (10 μL) was dissolved in acetone (100 μL) and 1 μL of the solution was injected into the GC/MS system with the following properties: helium was the carrier gas, used at a flow rate of 1 mL/min; split mode (1:25), with 1 μL (1/10 in acetone, v/v) as the injected volume and 300 °C as the injection temperature. The mass spectra of the obtained compounds were matched with those in the NIST11 library (Gaithersburg, MD, USA) [27 (link)].