Quantitative analysis of endocannabinoids and NAE analogues using the deuterated standards for AEA and 2-AG together with calculation of the other EC analogues was based on a ratio to the deuterated standards [30] and was performed on the Agilent 6410 Triple Quadrupole Liquid Chromatography-Mass Spectroscopy (TQMS) instrument using positive ion analysis mode.
To derive a comprehensive membrane proteome and N-glycoproteome from BV-2 cells, we analyzed several replicates on various mass spectrometric instruments using multiple strategies, based on recent advances in proteomics technologies, such as crude membrane fractionation, FASP-based differential sample preparation, and N-glyco-FASP-based glycopeptide enrichment.
We measured phthalate monoesters using high-pressure liquid chromatography followed by tandem mass spectrometry on a triple quadrupole instrument using atmospheric pressure chemical ionization.
Finally, where more information on the molecular structure is needed, e.g. to elucidate isomeric forms, further fragmentation is performed on selected masses within the ion-trap MS instrument, using collision-induced fragmentation.
Mass spectra were recorded on a Shimadzu QP-2010 instrusing using electron impact ionization (EI) at 70 eV.
Peptide identification was performed on the QTOF MS instrument using HPLC MS and MS MS in the accurate mass mode.
Choose your instrument using Smartmusic.
The retrieval of these groups is done without any a priori knowledge besides the following input parameters: (i) the mass difference between the unlabeled and labeled isotopes, (ii) the mass accuracy of the instrument used in the analysis, and (iii) the estimated retention-time reproducibility of the chromatographic method.
Chromatography was performed in an Agilent 6890 gas chromatograph (Agilent Technologies) coupled to a Pegasus III time-of-flight mass spectrometer (Leco Instruments) using a VF-5 ms capillary column (Varian; 30 m × 0.25 mm × 0.25 μm) including a 10-m guardian column with helium as carrier gas at a column flow rate of 1 mL min−1.
Besides, one additional −4 ion at m/ z 1529.1 is seen, with mass increment of 386.0 Da from intact insulin that is roughly equivalent to two dead-end tags (the mass deviation might be due to the low mass accuracy for LCQ DECA ion trap instrument used in this experiment).
