Metabolic profiling of serum using Ultra Performance Liquid Chromatography and the LTQ-Orbitrap mass spectrometry system

Identification of Metabolites of 6′-Hydroxy-3,4,5,2′,4′-pentamethoxychalcone in Rats by a Combination of Ultra-High-Performance Liquid Chromatography with Linear Ion Trap-Orbitrap Mass Spectrometry Based on Multiple Data Processing Techniques

“…In order to obtain as many fragment ions as possible, the peaks detected with intensity over 10,000 were selected for identification. The chemical formulas for all parent and fragment ions of the selected peaks were calculated from the accurate mass using a formula predictor by setting the parameters as follows: C (0-30), H (0-50), O (0-20), S (0-4), N (0-4), Cl (0-4) and ring double bond (RDB) equivalent value [0][1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Other elements such as P and Br were not considered as they are rarely present in the complex matrix.…”

“…Recently, with the development of various data acquisition methods, liquid chromatography-mass spectrometry (LC-MS), especially with high-resolution mass spectrometry (HRMS), has exhibited excellent performance for metabolite detection because of its high-speed and high detection sensitivity [9,10]. For example, the linear ion trap-Orbitrap mass spectrometer (LTQ-Orbitrap) used here combines a high trapping capacity and the MS n scanning function of the linear ion trap along with accurate mass measurements below 5 ppm and a resolving power of up to 30,000 [11][12][13]. Therefore, it is possible to obtain complex and information-rich metabolic fingerprints in a few minutes-from which m/z signals of interest could be extracted manually in targeted approaches, or by using statistical tools for global approaches [14,15].…”

Characterisation of the metabolome of ocular tissues and post-mortem changes in the rat retina

“…Deconvolution was performed using XCMS software 19 as described previously. 20 Whilst relative concentrations were measured no absolute quantification of metabolites to define concentrations per gram of tissue was performed. For quality assurance, only metabolite features detected in greater than 60% of QC samples and with a response not deviating greater than 20% from the QC mean were retained for further data analysis.…”

Natural Hormones in Food-Producing Animals:Legal Measurements and Analytical Implications

“…To this end, gas chromatography was first used, however, the necessary thermal stability of the investigated www.intechopen.com compounds, the required derivatization of non-volatile compounds prior to analysis and the frequent absence of molecular ions have made liquid chromatography coupled to atmospheric-pressure ionization a more and more used tool for metabolomics. Last generation of high resolution devices including time of flight and orbitrap instruments are becoming more and more used in this field due to their high performance in terms of sensitivity and specificity (Dunn et al, 2008;Scheltema et al, 2008).…”