Mixture instrumental time

Gas chromatography/mass spectrometry (GC/MS) is the synergistic combination of two powerful analytic techniques. The gas chromatograph separates the components of a mixture in time, and the mass spectrometer provides information that aids in the structural identification of each component. The gas chromatograph, the mass spectrometer, and the interface linking these two instruments are described in this chapter. 

Combinatorial Mixture Screening The increased popularity of LC/MS-based methods combined with limited resources resulted in advances that effectively matched combinatorial chemistry samples (i.e., complexity) with instrument time. Richmond, Yates, and coworkers (Richmond et al, 1999 Yates et al.,2001) demonstrated the use of flow injection analysis (FIA)-LC/MS systems for rapid purity assessment and combinatorial mixture screening, respectively. These LC/MS-based applications addressed two critical bottlenecks HPLC... 

Spot 0.7 pL of this solution directly onto the MALDI target. Add 0.4 pL of matrix solution and mix with the sample solution by aspirating the mixture five times. Prior to the measurement in the MALDI-TOF instrument, dry the samples on the target for 10-15 min. 

Finally, the speed of response of the detector sensor and the associated electronics once played an important part in optimum column design. The speed of response, or the overall time constant of the detector and associated electronics, would be particularly important in the analysis of simple mixtures where the analysis time can be extremely short and the elution of each peak extremely rapid. Fortunately, modern LC detector sensors have a very fast response and the associated electronic circuits very small time constants and, thus, the overall time constant of the detector system does not significantly influence column design in contemporary instruments. The instrument constraints are summarized in Table 2... 

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