Using 5–54 flowers from the same coffee plants, we collected 43 nectar samples of between 20–35 µl to measure nectar caffeine content (C. arabica: 8 shade, 10 sun; C. canephora: 13 shade, 12 sun). We immediately placed the nectar samples into a cooler with ice. They were then stored in a freezer at 0 ° C until they were lyophilized. Each sample was then diluted with 100 µl of methanol. Samples (5 µl) were analyzed directly by liquid chromatography-mass spectroscopy using a Dionex UltiMate 3000 LC system with separation of compounds on a Phenomenex Luna C18(2) column (150 Å~3 mm i.d., 3 μm particle size) at 400 μL min−1 and eluted using a linear gradient of 90:0:10 (t = 0 min) to 0:90:10 (t = 20–25 min), returning to 90:0:10 (t = 27–30 min). Solvents were water, methanol and 1% formic acid in acetonitrile, respectively. The column was maintained at 30 °C. Compounds were detected by MS on a Thermo Fisher Velos Pro Dual-Pressure Linear Ion Trap Mass Spectrometer. Samples were scanned, using FTMS, from m/z 194–196 corresponding to the molecular ion for caffeine (M + H = m/z 195.1) in positive mode. Peak areas were quantified against a calibration curve of an authentic caffeine standard (Sigma, Dorset, UK).
Velos pro dual pressure linear ion trap mass spectrometer
Manufactured by Thermo Fisher Scientific
Sourced in United States
The Velos Pro Dual-Pressure Linear Ion Trap Mass Spectrometer is a high-performance mass spectrometry instrument designed for analytical applications. It features a dual-pressure linear ion trap that allows for efficient ion trapping and mass analysis.
Automatically generated - may contain errors
Lab products found in correlation
Luna c18 2 column, by Phenomenex (2 mentions)
Ultimate 3000 lc system, by Phenomenex (1 mentions)
Dionex ultimate 3000 hplc, by Thermo Fisher Scientific (1 mentions)
C16 18 1 pc, by Avanti Polar Lipids (1 mentions)
C18 plasm 20 4 pc, by Avanti Polar Lipids (1 mentions)
Nanoacquity uplc, by Waters Corporation (1 mentions)
Formononetin, by Merck Group (1 mentions)
Orientin, by Merck Group (1 mentions)
Vitexin, by Merck Group (1 mentions)
Apigenin, by Merck Group (1 mentions)
Luteolin, by Merck Group (1 mentions)
Daidzein, by Merck Group (1 mentions)
Vicenin 2, by Merck Group (1 mentions)
Avance 800, by Bruker (1 mentions)
Avance 500, by Bruker (1 mentions)
Agilent 1260 infinity 2 system, by Agilent Technologies (1 mentions)
7 protocols using velos pro dual pressure linear ion trap mass spectrometer
1
Quantifying Caffeine in Coffee Nectar
2
Quantitative Lipid Profiling via HPLC-MS
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
This step was performed as described previously (40 (link)), modified and extended to also allow quantification and fragmentation of glycerophosphocholines and glycerophosphoethanolamines. Internal standards were added to cell homogenates, and lipids were extracted via the Folch procedure (41 (link)). Dried lipid extracts were dissolved in HPLC starting condition, separated by reversed-phase HPLC on a Dionex Ultimate 3000 HPLC (Thermo Fisher Scientific), and quantified with a Velos Pro Dual-Pressure Linear Ion Trap Mass Spectrometer (Thermo Fisher Scientific). Baseline corrected data were integrated in MZmine 2 (42 (link)), quantified, and visualized as described previously (40 (link)) using custom-made scripts in R (https://www.R-project.org/ ). Molecular PE, PC, plasmanyl-PE and plasmenyl-PE species were identified by their retention time, monoisotopic mass-to-charge ratio, isotope pattern, and fragmentation behavior (SI Appendix, Fig. S5 and Materials and Methods ), which was cross-validated with single lipid standards commercially available from Avanti Polar Lipids: C16-18:1 PC, C18(Plasm)-22:6 PC, C16-18:1 PE, C18(Plasm)-18:1 PC, C18(Plasm)-18:1 PE, and C18(Plasm)-20:4 PC.
3
LC-MS/MS Tryptic Peptide Analysis
4
NMR and Mass Spectrometry Analysis
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
1H NMR and 13C NMR spectra were obtained in D2O on an Avance 400 spectrometer (Bruker BioSpin GmbH, Rheinstetten, Germany) at 400.13 and 100.61 MHz, respectively. Chemical shifts for 1H NMR and 13C NMR signals are given in ppm at 300 K, with 2-methyl-2-propanol as an internal standard (1.23 and 31.3 ppm, respectively). The following abbreviations are used for the characterization of NMR signals: s = singlet, d = doublet, t = triplet, and m = multiplet. ESI-Orbitrap-MS spectra were recorded on a Velos Pro Dual-Pressure Linear Ion Trap Mass Spectrometer (Thermo Fisher Scientific, Inc., Waltham, USA).
5
Fenugreek Compound Profiling by LC-PDA-MS
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The fenugreek sprout and seed extracts were analysed at 50 mg/mL in duplicate using a Thermo Fisher Velos Pro LC-PDA_MS. Samples (5 μL) were injected directly onto a Phenomenex Luna C-18 (2) column (150 mm, 3 mm i.d., 3 μm particle size) at 400 μL/min and eluted using a linear gradient of 90:0:10 (t = 0 min) to 0:90:10 (t = 20–25 min), returning to 90:0:10 (t = 27–30 min). The solvents were water, MeOH, and 1% formic acid in acetonitrile, respectively. The column was maintained at 30 °C. Compounds were detected with a Thermo Fisher Velos Pro Dual-Pressure Linear Ion Trap Mass Spectrometer. Samples were scanned using the ITMS from m/z 200 to 600, and the UV peak areas were quantified against the calibration curves of the reference standards (apigenin, vicenin-2, vitexin, luteolin, orientin, formononetin, and daidzein; Sigma), which were analysed in duplicate over a concentration range of 0.32–2000 µg/mL using the same LC–PDA-MS method.
6
NMR and Mass Spectrometry Analysis
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
One-dimensional (1H and 13C) and two-dimensional [double-quantum-filtered correlation spectroscopy (DQF-COSY), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple-bond correlation (HMBC)] nuclear magnetic resonance (NMR) spectra were recorded using a Bruker Avance 500 or Avance 800 spectrometer (Bruker Biospin GmbH, Rheinstetten, Germany) in D2O with 2-methyl-2-propanol as the internal standard (1.23 ppm for 1H, 31.3 ppm for 13C) or in dimethyl sulfoxide (DMSO)-d6 referring solvent signals as the internal standard (2.49 ppm for 1H, 39.5 ppm for 13C) at 298 K. Signals were assigned using cross signals in the 2D spectra. Ring structures were confirmed with the cross signal on HMBC spectra. Electrospray ionization mass spectrometry (ESI-MS) was performed using a Velos Pro Dual-Pressure Linear Ion Trap Mass Spectrometer (Thermo Fisher Scientific Inc., Waltham, USA).
7
Recombinant Protein Desalting and Mass Spectrometry
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The recombinant protein was diluted to a final concentration of 3 or 0.8 µM in buffer I (20 mM Hepes pH 8.0, 50 mM NaCl) and treated with DMSO/compound to result in a final concentration of 10 or 1 µM, respectively. Followed by incubation of 1 h at room temperature, the samples were either run through a MassPrep Online Desalting 2.1 mm × 10 mm cartridge (Waters, flow rate 0.5 mL/min, runtime 7 min, column temperature 30 °C) or an AdvanceBio DesaltingRP 2.1 mm × 12.5 mm cartridge (Agilent, flow rate 0.4 mL/min, runtime 6 min, column temperature 32 °C) with solvents A = HPLC-grade H2O + 0.1% TFA or formic acid and solvent B = HPLC-grade acetonitrile + 0.1% TFA or formic acid as mobile phases, respectively. A gradient from 20–90% solvent B (MassPrep Online Desalting cartridge) or 5–95% solvent B (AdvancedBio DesaltingRP) was programmed. The samples were either analyzed on a Velos Pro Dual-Pressure Linear Ion Trap mass spectrometer (ThermoFisher, with Xcalibur software), equipped with an electrospray ion source in positive mode (capillary voltage 5 kV, desolvation gas flow 40 L/min, temperature 275 °C) or on an Agilent 1260 II Infinity system (Agilent, with Openlab software), equipped with an electrospray ion source in positive mode (capillary voltage 4 kV, desolvation gas flow 80 L/min, temperature 350 °C). Spectra were deconvoluted with ProMass (Enovatia).
About PubCompare
Our mission is to provide scientists with the largest repository of trustworthy protocols and intelligent analytical tools, thereby offering them extensive information to design robust protocols aimed at minimizing the risk of failures.
We believe that the most crucial aspect is to grant scientists access to a wide range of reliable sources and new useful tools that surpass human capabilities.
However, we trust in allowing scientists to determine how to construct their own protocols based on this information, as they are the experts in their field.
Ready to get started?
Sign up for free.
Registration takes 20 seconds.
Available from any computer
No download required
Revolutionizing how scientists
search and build protocols!