Qp 5000 mass spectrometer

After microbial analysis, the rest of fresh musk was dried by exposure to phosphorus pentoxide (P₂O₅). We weighed the musk every 30 minutes until its weight ceased to change. Because a very small amount of musk remained for the mated group after bacterial DNA extraction and musk dehydration so we pooled three samples together (taking 0.07 gram of each sample, total 0.21 gram). After blending, each 0.1 gram of musk was dissolved in 2.5 ml absolute ethyl alcohol (purity > 99.7%) or 2.5 ml diethyl ether (purity > 99.5%), then extracted by ultrasonic for two hours. The dissolved samples were centrifuged at 13000g for 5 minutes and the liquid supernatant was used for chemical components analysis. The same method was applied for unmated (sample UM1, UM2 and UM3) males.
A Shimadzu GCMS-QP 2010 plus gas chromatograph (Shanghai, China), coupled to a Shimadzu QP 5000 mass spectrometer which was equipped with a split/split less injector and a DB5-MS column [(30 m × 0.25 mm i.d., 0.25 mm film thickness), (Agilent J&W, Agilent Technologies, CA, USA)] was used for the chromatographic analysis of the targeted compounds. The mass spectral data base NIST08.LIB was used to analyze the data. The confidence coefficient of the data above 80% was adopted.

The volatile composition of the YD powders was characterized by SPME–GC–MS, as reported previously (Comuzzo et al. 2015b (link)). Analyses were carried out using a GC-17A gas chromatograph equipped with a QP-5000 mass spectrometer (Shimadzu, Kyoto, Japan). Autolysate samples (2.00 g) were introduced in 50 mL amber glass vials sealed with PTFE/silicone septa. Vials were pre-conditioned for 15 min at 40 °C before microextraction, and SPME was run at the same temperature for 15 min, using a 2 cm 50/30 µm divinylbenzene/carboxen/polydimethylsiloxane fiber (Supelco, Bellefonte, PA, USA). A J&W DB-Wax capillary column, 30 m × 0.25 mm i.d., 0.25 µm film thickness (Agilent Technologies Inc., Santa Clara, CA, USA) was used for the GC separation, with the following operating conditions: 40 °C for 1 min, then 4 °C min⁻¹, up to 240 °C, with a final holding of time of 15 min. Injection was performed in splitless mode with 60 s of splitless time; injection port and transfer line were set at 250 and 240 °C respectively. Carrier gas was helium, at a linear flow rate of 35 cm s⁻¹.

The volatile scent of blooming flowers was trapped on SPME (solid phase micro extraction), which was desorbed at the injection port at 210 °C for 1 min. The analysis was performed using Shimadzu gas chromatograph (Model GC-17A) coupled with Shimadzu model QP-5000 mass spectrometer (Tokyo, Japan) according to Farag et al., 2017^{49 (link)}. The identification of volatile components was established using AMDIS software (https://www.amdis.net) along with their retention indices (RI) as compared to n-alkanes (C6–C20). In addition to, mass spectrum matching with NIST, WILEY library database using matching score more than 800.

SPME-GC/MS was used for analysis of serum volatile metabolites. A volume of 200 μL of serum was placed in 1.5 mL SPME vial. The vial was then sealed with a teflon lined magnetic cap using a hand crimper for volatiles collection. A 50 μm/30 μmDVB–CAR–PDMS metal SPME fiber (Supelco, USA) was inserted into the headspace above serum. The vial was placed at 50 °C and adsorption of volatiles was done for 30 min. Fibers were desorbed at 210 °C for 1 min in the injection port of a GC-17A gas chromatograph interfaced with a QP-5000 mass spectrometer (Shimadzu, Japan). GC separation of volatiles was carried out on a DB-5 ms column (Agilent, 30 m length, 0.25 mm inner diameter, and 0.25 μm film, non-polar phase, phenyl arylene polymer). Identification of volatiles was performed using the procedure described by Farag et al.61 (link). Briefly, peaks were first deconvoluted using AMDIS software then identified by its RI relative to the standard n-alkanes mixture (C₈-C₄₀). Identities of metabolites were further confirmed by matching their mass spectra to NIST and WILEY library database.

Bis(1H-indol-3-yl)methane (compound 5) and all organic solvents that were used in this study were purchased from Sigma (Milan, Italy). Prior to use, acetonitrile was dried with molecular sieves with an effective pore diameter of 4 Å. Column chromatography purifications were performed under ‘‘flash” conditions using Merck 230–400 mesh silica gel. Analytical thin-layer chromatography (TLC) was carried out on Merck silica gel plates (silica gel 60 F254), which were visualized by exposure to ultraviolet light and an aqueous solution of cerium ammonium molybdate (CAM). ESI-MS spectra were recorded with a Waters Micromass ZQ spectrometer). EI-MS spectra were recorded with a Shimadzu QP-5000 Mass spectrometer. ¹H NMR and ¹³C NMR spectra were recorded on a Bruker AC 400 or 100, respectively, spectrometer and analyzed using the TopSpin software package. Chemical shifts were measured by using the central peak of the solvent.

The hydrocarbons content in soil was determined using the headspace method and capillary gas chromatography with mass detection (GC-MS). A Shimadzu GC-14A gas chromatograph was coupled to a Shimadzu QP 5000 mass spectrometer. Analyses were made according to the standard ISO 16703:2009 [50 ].

The chemical characterization of the essential oil of the floral buds of S. aromaticum was determined by gas chromatograph coupled to Shimadzu QP5000 mass spectrometer (Shimadzu, Kyoto, Japan), equipped with a capillary column ZB-5ms (5% phenyl arylene) 95% dimethylpolysiloxane, with HP 5MS electronic impact detector of 70 eV (40-500 Da) and transfer temperature of 280°C. Aliquots were injected in splitless mode with a volume of 0.3 µL in ethyl acetate (automatic injector CP-8410), fixing the following conditions: high purity helium as carrier gas; injector temperature maintained at 280°C, split mode (1 : 10); followed by an initial temperature of 40°C and a final temperature of 300°C, an initial time of 5 min and a final time of 7.5 min at 8/min.