TY  - JOUR
AB  - In the field of metabolomics, researchers seek to acquire almost 
      complete information about the metabolic composition of a sample to 
      provide fundamental information about the cellular state of organisms. 
      In metabolomics analysis today, typically reversed-phase (RP) liquid 
      chromatography (LC) is coupled with specific, sensitive, and robust mass
       spectrometry (MS). That approach, however, misses many moderately 
      polar, and all very polar, compounds; this situation is a problem in 
      plant metabolomics, because plant metabolites are mainly water-soluble 
      species and thus very polar. Here, we describe new developments in 
      polarity-extended separations using the serial coupling of 
      reversed-phase LC and hydrophilic-interaction chromatography (HILIC) 
      separation steps, in combination with electrospray 
      ionization-time-of-flight-mass spectrometry (ESI-TOF-MS), and the 
      application of this approach to plant metabolomics. The resulting 
      retention time versus mass plots are molecular fingerprints, as well as 
      sources of further molecular descriptors. Extraction methods, molecular 
      analysis, and data evaluation have to be adapted to the matrix under 
      consideration. Representative strategies using this polarity extending 
      approach, following so-called suspects and nontargeted screening approaches, are presented.
AU  - Wahman, R.*
AU  - Grassmann, J.*
AU  - Schröder, P.
AU  - Letzel, T.*
C1  - 57941
C2  - 48007
SP  - 8-15
TI  - Plant metabolomic workflows using reversed-phase LC and HILIC with ESI-TOF-MS.
JO  - LC GC N. Am.
VL  - 37
IS  - 3
PY  - 2019
SN  - 1527-5949
ER  - 

TY  - JOUR
AB  - Matrix-assisted laser desorption-ionization (MALDI) imaging mass spectrometry (IMS) is a powerful tool in histopathological characterization and represents a modern analytical technique, enabling two-dimensional detection of molecular components of biological samples. Using this method, it is possible to investigate the spatial distribution of proteins, lipids, carbohydrates, cholesterols, nucleic acids, phospholipids, and small molecules in biological systems by in-situ analysis of cell cultures and tissue sections. Recently, MALDI-IMS has become an essential tool for tissue analyses in life science applications, offering global analysis of tissue samples. An advantage of this imaging technique is the acquisition of local molecular expression profiles up to the microscopic level, while maintaining the topographic integrity of the tissue by avoiding time-consuming extraction, purification, or separation steps, respectively. With MALDI-IMS it is possible to determine the distribution of hundreds of unknown compounds in a single measurement, allowing rapid probing of the tissues' biochemistry. Moreover, MALDI-IMS results include qualitative and semiquantitative information, providing unique chemi-morphological information about the tissue status, which represents an important benefit for future analytical interpretation of pathological changes of a tissue. This article summarizes the most recent advances in sample preparation, instrumentation, and data-processing techniques for MALDI-IMS.
AU  - Pallua, J.D.*
AU  - Schaefer, G.*
AU  - Bittner, L.K.*
AU  - Pezzei, C.*
AU  - Huck-Pezzei, V.*
AU  - Schoenbichler, S.A.*
AU  - Meding, S.
AU  - Rauser, S.
AU  - Walch, A.K.
AU  - Handler, M.*
AU  - Netzer, M.*
AU  - Osl, M.*
AU  - Seger, M.*
AU  - Pfeifer, B.*
AU  - Baumgartner, C.*
AU  - Lindner, H.*
AU  - Kremser, L.*
AU  - Sarg, B.*
AU  - Klocker, H.*
AU  - Bartsch, G.*
AU  - Bonn, G.K.*
AU  - Huck, C.W.*
C1  - 4866
C2  - 29442
CY  - Duluth, MN, USA
SP  - 21-28
TI  - Matrix-assisted laser desorption-ionization imaging mass spectrometry for direct tissue analysis.
JO  - LC GC N. Am.
VL  - Suppl. S
PB  - Advastar Communications Inc.
PY  - 2011
SN  - 1527-5949
ER  -