LCGC Europe-11-01-2008

LCGC Europe

LC–API-MS(/MS) for Biological Samples: Importance of Hydrophobicity, Molecular Weight and Structural Development

November 01, 2008

Regular article

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The combination of reversed-phase high performance liquid chromatography (RP-HPLC), atmospheric pressure ionization (API), mass spectrometry (MS) and tandem mass spectrometry (MS/MS) is ideal for determining and characterizing analytes in complex biological matrices. This review looks at the importance of parameters such as hydrophobicity, ionization properties, molecular mass and, partially, the molecular structure resulting from applied LC–MS–MS systems in analytical laboratories. The use of these parameters to investigate biomolecules and their unambiguous identification is also described.

Comprehensive 2D GC–QPMS with Differential Flow Modulation

November 01, 2008

Coupling Matters

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Differential flow modulation is an inexpensive way to perform GCÃ-GC separations which has been attracting growing attention recently. Differential flow modulation uses high carrier gas flow rates in the second dimension column so it is widely thought that this rules out direct coupling with mass spectrometry. However direct coupled GCÃ-GC-QPMS using differential flow modulation is reported here for the first time using an unmodified mass spectrometer comprising a dual inlet turbomolecular pump and fast scanning quadrupole mass analyser. The suitability of the approach for characterization of essential oils is demonstrated.

A Shock to the System

November 01, 2008

GC Connections

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This month in "GC Connections", in the first of a two-part series, John Hinshaw relates what happens when high-voltage spikes attack modern electronic equipment, what to do when they occur, and how to set up equipment to minimize damage and loss of data.