All the reagents and solvents used in this study were bought from commercial sources. The NMR spectra were recorded in acetone-d6 solvent using 5-mm tubes, at 298 K, with a Varian Mercury Plus 400, (Varian Inc., Palo Alto, CA, USA) operating at 400 (1H) and 100 MHz (13C). The chemical shifts were referenced to acetone: δ (H) 2.04 ppm and δ (C) 29.0 ppm. Some 13C-NMR spectra were acquired in non-deuterated acetone; in this case, a capillary filled with C6D6 (secondary standard [33 (link)]) was placed into the 5-mm tube and the sample was locked and shimmed on C6D6 contained in the secondary standard, and the chemical shifts were also referenced to C6D6: δ (C) 127.6 ppm. ESI mass spectra were obtained using an LCQ Duo (ThermoQuest, San Jose, CA, USA) in negative-ion mode. Instrumental parameters were as follows: capillary voltage −10 V, spray voltage 4.50 kV, mass scan range was from m/z 100 to 2000 amu, for 30,000 ms of scan time; N2 was used as sheath gas. The samples were injected into the spectrometer through a syringe pump at a constant flow rate of 8 mL/min.
Lcq duo
Manufactured by Thermo Fisher Scientific
Sourced in United States
The LCQ Duo is a mass spectrometry system designed for liquid chromatography-mass spectrometry (LC-MS) applications. It provides high-performance ion trap mass analysis capabilities for a wide range of analytical requirements.
Automatically generated - may contain errors
Lab products found in correlation
Varian mercury plus 400, by Agilent Technologies (1 mentions)
Thermo finnigan, by Thermo Fisher Scientific (1 mentions)
Ft ir paragon 500, by PerkinElmer (1 mentions)
Flash 2000, by Thermo Fisher Scientific (1 mentions)
Bvt 3000 temperature controller, by Bruker (1 mentions)
Avance dmx 600 mhz spectrometer, by Bruker (1 mentions)
Avance 300, by Bruker (1 mentions)
8 protocols using lcq duo
1
NMR and ESI-MS Characterization of Compounds
2
ESI-MS Analysis of Photocatalytic Dye
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Mass spectra of the dye solution subjected to photocatalysis were recorded using an LCQ Duo (ThermoQuest, San Jose, CA, USA), equipped with an electrospray ionization source (ESI), monitoring the precursor-to-product ion transitions of m/z 100 to 400 in the negative ionization mode. In order to accomplish ESI-MS analysis without interference of ionic species, photocatalysis was carried out with ethanol (10% v/v) instead of HCOONa as a nonionic hole scavenger.
3
Phytochemical Profiling of Plant Extract
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The chemical constituents of the tested extract were tentatively identified using a Thermo Finnigan (Thermo electron Corporation, OK, USA), coupled with an LCQ Duo ion trap mass spectrometer with an ESI source in negative ionization mode (ThermoQuest Corporation, Austin, TX, USA)54 (link). The ethyl acetate extract (20.0 g) was consequently fractionated via using column chromatography (5 × 60 cm) packed with polyamide 6S as a stationary phase and eluted via a gradient mix elution system (Water: MeOH). A total of five major sub-fractions (F1–F5) were obtained. The obtained sub-fractions (F1–F4) were separately subjected to further extra purification using a multiple Sephadex LH-20 sub-columns (2 × 30 cm) eluted with (Water: MeOH with MeOH gradient) to obtain gallic acid, methyl gallate, p-coumaric acid, quercetin, taxifolin, naringenin, and quercetin 3-O-glucoside. While F5 (5.2 g) eluted by 85% MeOH from the main polyamide column was subjected to multiple Sephadex LH-20 sub-columns for extra purification eluted with methanol:water in gradient mix elution system to obtain ESC.
4
Characterization of Organic Compounds
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Thin layer chromatography (TLC) was performed on pre-coated silica gel glass plates 60F254 (thickness 0.25 mm, Merck). Reagents and compounds were detected under short wavelength UV light and by heating after spraying with a 5% phosphomolybdic acid solution. Silica gel (Fluka, Kieselgel 60, 70-230 mesh) was used for preparative column chromatography. 1 H and 13 C-NMR spectra were recorded on 400 MHz spectrometers in CDCl3 at room temperature. Chemical shifts are given in parts per million (ppm); J values are given in hertz (Hz). All spectra were internally referenced to the appropriate residual undeuterated solvent. Mass spectra were recorded using a LCQ Duo (ThermoQuest, San Jose, CA, USA), equipped with an electrospray ionization (ESI) source. IR spectra were recorded on a Perkin-Elmer FT-IR Paragon 500.
5
Degradation Product Identification via LC-MS
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The degradation products were identified by LC-MS analysis of culture samples inoculated with MSM at 0 hr and 24 h (Asses et al., 2018 ; Wanyonyi et al., 2019 ). Aliquots of samples were taken and biomass was separated by centrifugation at 7000 rpm for 20 min at 4 °C, followed by membrane filtration using membrane of 0.2 μm diameter. Mixture of methanol and Millipore water in the ratio of 7:3 (v/v) and 0.02 M phosphate buffer were used as the mobile phase in a gradient elution program. HPLC Accucore (C18, 150 2.1, 2.6 um) was equipped with a photo diode array detector at 254 nm for the LC-MS analysis, which was performed by LCMS -ACQTQD#QBB1152. As a mobile phase, methanol: water was employed (with a volumetric ratio of 50:50) with a flow rate of (0.1 ml/min), and the injected sample was 10 l. An ion-trap spectrometer equipped with electron spray ionization was used to transfer the sample to the MS detector (ESI, Mass spectra were extracted Thermo Finnigan LCQ-DUO, USA). It was discovered that mass spectra could be obtained at voltages of 4.5 kV, capillary temperatures of 275–280 °C, and sheath gas concentrations as high as 40 AU (arbitrary units).
6
Characterization of Monomers and Polymers
7
Synthesis and Characterization of 1-Mesityl-1H-Imidazole
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All manipulations and synthesis were carried out using standard Schlenk techniques under inert atmosphere of argon, or in a dry box MBraun Labmaster operating in dinitrogen atmosphere. The reagents and solvents were purchased as high-purity products and used as received. 1-mesityl-1H-imidazole was synthesized according to a procedure published in the literature [45 ]. NMR spectra were recorded at room temperature (298 K) on a Bruker Avance 300 MHz spectrometer (300.1 MHz for 1H, 75.5 MHz for 13C); chemical shifts (δ) are reported in ppm relative to the residual solvent signals. The ESI-MS analysis was performed using a Thermo-Finnigan LCQ-Duo (San Jose, CA, USA) coperating in positive mode. The elemental analysis was carried out with a Thermo Scientific FLASH 2000 apparatus.
8
Characterization of Organometallic Complexes
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All the commercially available reagents were used as received without additional purification. Complexes 1 –4 were prepared according to procedures established in the literature [25 (link)]. The NMR spectra were usually recorded on a Bruker Avance 300 (300.1 MHz for 1H and 75.5 MHz for 13C) at 298 K; the spectra of complex 8 were also recorded on a Bruker Avance DMX-600 MHz spectrometer operating at 599.90 MHz for 1H and 150.61 MHz for 13C, respectively. The temperature was controlled (±0.1 °C) with a Bruker BVT-3000 temperature controller; chemical shifts (δ) are reported in units of ppm relative to the residual solvent signals. ESI-MS analyses of the new compounds were performed using an LCQ-Duo (Thermo-Finnigan, San Jose, CA, USA) operating in positive ion mode, dissolving the compounds in acetonitrile, and directly infusing the prepared solution into the ESI source using a syringe pump.
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