Detector optical multichannel analysis

Figure 7. Spectral contributions of transient electronic configurations triggered by the femtosecond UV excitation of aqueous chloride ions. The relative spectral contributions are obtained from the computed analysis of time-resolved UV-IR femtosecond spectroscopic data. A first photophysical channel, including a non-adiabatic transition from a p-like excited hydrated electron state (e hydV to an s-like ground hydrated electron state. B spectral contributions of two well-defined transient fe Cl pairs. The presence of counterions (Na ) influences the dual behavior of these transient electronic configurations. C Direct identification of the spectral band assigned to near-infrared fe Cl pairs, made by using a cooled Optical Multichannel Analyzer (OMA 4) equipped with CCD detectors (1024 X...

Topics which will be presented in this chapter include the hardware, software, automation, valve and column configurations, and integration used in comprehensive 2DLC. Aspects of the 2DLC experiment in conjunction with multichannel detectors such as UV diode array optical detectors and mass spectrometers are discussed along with the handling of the data, which is expected to expand in scope in the future as chemometric methods are more widely used for data analysis. 

A multichannel detector for In-situ analysis of fluorescent materials on TLC plates was investigated (26). The optical system was designed to obtain a fluorescence spectrum from each position along the elution axis of a one-dimensional plate without the mechanical scanning. By use of tetraphenylporphlne and octaethylporphine it can be shown how overlapping spots can be resolved into their components. 

The future of Raman microspectroscopy is probably imaging and optical near-field nano-Raman spectroscopy [529], cfr. Chp. 5.5.2. While conventional laser Raman spectroscopy samples 10 g (mm ), /zRS handles 10 g (nm ) and near-field Raman spectroscopy 10 g (nm ). Mobile Raman microscopy (MRM) allows in situ Raman analysis [530]. One can expect further developments in the field of NIR multichannel Raman spectroscopy with the advent of 2D array detectors offering extended response in the NIR. With these 2D sensors it wiU become possible to apply in the NIR region the powerful techniques already developed in the visible, such as confocal line imaging techniques or multisite remote analysis with optical fibres. 

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