Multiple wavelength detector

Since modern FTIR spectrometers can operate in a rapid scan mode with approximately 50 ms time resolution, TRIR experiments in the millisecond time regime are readily available. Recent advances in ultra-rapid scanning FTIR spectroscopy have improved the obtainable time resolution to 5 ms. Alternatively, experiments can be performed at time resolutions on the order of 1-10 ms with the planar array IR technique, which utilizes a spectrograph for wavelength dispersion and an IR focal plane detector for simultaneous detection of multiple wavelengths. ... 

Two aiproaches have been taken for the design of multiple-wavelength detectors [65-58,73-75]. The first approach uses conventional forward optics and a rapidly movipg holographic... 

These detectors are based on selective absorption of ultraviolet or visible light by the desired solute. A large number of single or multiple wavelength... 

Hewlett Packard Multiple wavelength detector 1050 series... 

It seems that the PDA is not fully utilized. When quantitative measurements are performed, most of the spectral information is often ignored, since detector s response is locked on a single wavelength (or two). Multicomponent analysis uses multiple wavelengths to deconvolute the unresolved peaks and provides accurate quantitation independent of peak resolution and peak shape. 

The most commonly-used detectors are those based on spectrophotometry in the region 184-400nm, visible ultraviolet spectroscopy in the region 185-900nm, post-column derivativisation with fluorescence detection (see below), conductivity and those based on the relatively new technique of multiple wavelength ultraviolet detectors using a diode array system detector (described below). Other types of detectors available are those based on electrochemical principles, refractive index, differential viscosity and mass detection. 

THIS SYSTEM IS COMPOSED OF XXX SUBPROGRAMS WHICH ACQUIRE DATA FROM A DUAL BEAM MULTIPLE WAVELENGTH DETECTOR IN A CONFIGURATION FOR USE WITH A HIGH PRESSURE LIQUID CHROMATOGRAPH. 

For all types of chemical analysis, the quality of the results ultimately relates to the chemical purity of the best available SRM. For naturally chiral substances, there is the additional more serious concern over what constitutes absolute enantiomeric purity. Not even mass spectroscopy, which provides assurance that a substance is chemically pure, can be used to report absolute enantiomeric purities. To actually report an enantiomeric purity higher than 99% is truly beyond the capability of current analytical methodology. ° As noted previously, the fact is that results are measured relative to an enantiopurity defined to be 100%. Chemical purities aside, the measurement of enantiomeric purity and enantiomeric excess is technically the same, the difference being the extent of race-mization. There are only two experimental options, either enantiomeric separations or multivariate spectroscopic analyses, that involve either two distinct detectors or multiple-wavelength detection for a single detector, as noted above. The newly described derivati-zation reactions fulfill the second option. 

Photodiode array A linear array of photodiodes that can detect multiple wavelengths simultaneously see diode array detector. Photoelectric colorimeter A photometer that responds to visible radiation. 

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