TY  - JOUR
AB  - Metabolite identification is a crucial step in nontargeted metabolomics, but also represents one of its current bottlenecks. Accurate identifications are required for correct biological interpretation. To date, annotation and identification are usually based on the use of accurate mass search or tandem mass spectrometry analysis, but neglect orthogonal information such as retention times obtained by chromatographic separation. While several tools are available for the analysis and prediction of tandem mass spectrometry data, prediction of retention times for metabolite identification are not widespread. Here, we review the current state of retention time prediction in liquid chromatography-mass spectrometry-based metabolomics, with a focus on publications published after 2010.
AU  - Witting, M.
AU  - Böcker, S.*
C1  - 58540
C2  - 48317
CY  - Postfach 101161, 69451 Weinheim, Germany
SP  - 1746-1754
TI  - Current status of retention time prediction in metabolite identification.
JO  - J. Sep. Sci.
VL  - 43
IS  - 9-10
PB  - Wiley-v C H Verlag Gmbh
PY  - 2020
SN  - 1615-9306
ER  - 

TY  - JOUR
AB  - A novel method for the separation and detection of low molecular weight (LMW) acids was developed using monolithic immobilized pH gradient-based capillary isoelectric focusing coupled with mass spectrometry. Two main parameters, focusing conditions and delivery buffer conditions, which might affect separation efficiency, were optimized with the focusing time of 7 min at 350 V/cm and the delivery buffer of 50% (v/v) acetonitrile in 10 mmol/L ammonium formate (pH 3.0). Under these conditions, the linear correlation between the volume of delivery solvent and the pK(a) of the model components was observed. In addition, the separation mechanism of LMW acids was proposed as well. We suppose that this method may provide a useful tool for the characterization of LMW components (e.g. natural organic matter of different origins).
AU  - Wang, T.T.*
AU  - Fekete, A.
AU  - Gáspár, A.
AU  - Ma, J.F.*
AU  - Liang, Z.*
AU  - Yuan, H.M.*
AU  - Zhang, L.H.*
AU  - Schmitt-Kopplin, P.
AU  - Zhang, Y.K.*
C1  - 6291
C2  - 28333
SP  - 422-427
TI  - Analysis of low molecular weight acids by monolithic immobilized pH gradient-based capillary isoelectric focusing coupled with mass spectrometry.
JO  - J. Sep. Sci.
VL  - 34
IS  - 4
PB  - Wiley-Vch Verl.
PY  - 2011
SN  - 1615-9306
ER  - 

TY  - JOUR
AB  - In tobacco research, the comparison of different tobacco blends as well as the puff-dependent behaviour of cigarettes is a matter of particular interest. For the investigation of smoke characteristics, GC x GC offers different ways for data analysis, namely, compound target analysis, automated peak-based compound classification and comprehensive pixel-based data analysis. This study will show the application as well as the pros and cons of these types of data analysis for very complex matrices like cigarette particulate matter. In addition, new aspects about the recently discovered puff-dependent behaviour of compounds in cigarette smoke will be presented. Automated peak-based compound classification including mass spectrometric pattern recognition is used for the classification of tobacco particulate matter samples and the puff-dependent investigation of different compound classes. This compound group specific analysis is further reinforced by applying an even more comprehensive pixel-based analysis. This kind of analysis is used to generate fingerprints of different types of cigarettes. The combination of fast feature reduction methods like analysis of variance (ANOVA) and t-test with multivariate feature transformation methods like partial least squares discriminate analysis (PLSDA) for feature selection provides a powerful tool for a detailed inspection of different types of cigarettes.
AU  - Gröger, T.M.
AU  - Welthagen, W.
AU  - Mitschke, S.*
AU  - Schaeffer, M.*
AU  - Zimmermann, R.
C1  - 2340
C2  - 25835
SP  - 3366-3374
TI  - Application of comprehensive two-dimensional gas chromatography mass spectrometry and different types of data analysis for the investigation of cigarette particulate matter.
JO  - J. Sep. Sci.
VL  - 31
IS  - 19
PB  - Wiley-VCH
PY  - 2008
SN  - 1615-9306
ER  - 

TY  - JOUR
AU  - Schnelle-Kreis, J.*
AU  - Welthagen, W.
AU  - Sklorz, M.*
AU  - Zimmermann, R.
C1  - 4808
C2  - 22905
SP  - 1648-1657
TI  - Application of direct thermal desorption gas chromatography and comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry for analysis of organic compounds in ambient aerosol particles.
JO  - J. Sep. Sci.
VL  - 28
PY  - 2005
SN  - 1615-9306
ER  -