Variable wavelength

Figure 3 depicts profiles of Total PAH fluxes vs. time (36). The following polycyclic hydrocarbons have been determined by high performance liquid chromatography, variable wavelength absorption detection Naphthalene, acenaphthylene, 7,12-dimethylbenzanthracene, 2-methylnaphtalene, fluorene, acenaphtene, phenanthrene, 2,3-dimethylnaphtalene, anthracene, fluoranthene, 1-methylphenanthrene, pyrene, 2,3-benzofluorene, triphenylene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, perylene, benzo(e)pyrene, 1,2,3,4-dibenzanthracene, benzo(a)pyrene, and 1,2,5,6-dibenzanthracene. 

In order to calculate particle size distributions in the adsorption regime and also to determine the relative effects of wavelength on the extinction cross section and imaginary refractive index of the particles, a series of turbidity meas irements were made on the polystyrene standards using a variable wavelength UV detector. More detailed discussions are presented elsewhere (23) > shown here is a brief summary of some of the major results and conclusions. 

Kratos Spectroflow 400 LC pumps ABI Model 783 variable-wavelength ultraviolet (UV) detector... 

Figure 5.8 Scheaatic optical diagram of a variable wavelength dual beam absorption detector. A, and a photodiode array detector with reverse optics, B.

Stewart, J. E., Spectral-bandwidth effects of variable-wavelength absorption detectors in liquid chromatography, ]. Chromatogr., 174, 283, 1979. 

Both fixed and variable wavelength uv/visible detectors are available. The variable types use a deuterium and/or a tungsten filament lamp as the radiation source and can operate between about 190-700 nm. They will have a number of absorbance ranges (ranges are given... 

Variable-wavelength detector, showing deuterium lamp, optical path, reference photodiode and monochromator. 

Omura et al.21 used a reverse phase high performance liquTcT cEromatographic column, JASCO PACK SV-02-500, for macrolide antibiotics with methanol, M/15 acetate buffer pH 4.9, and acetonitrile (35 60 5) as solvent. A variable wavelength UV detector using the absorption of the individual compounds gave the required sensitivity. Alterations of buffer pH and the composition ratio of the mobile phase gave selectivity for separation of individual macrolide antibiotics. 

Series 10 chromatography LC-95 variable wavelength UV/visible detector, LC-90 variable wavelength UV detector, LC-135 and L-235 diode array detectors, LC 1-100 computing integrator, 1SS-100 intelligent amjj in s stjm, Series 410 LC pump... 

HP 1050 Series comprising programmable variable-wavelength wavelength detector, pumping system, autosampler... 

Series 100 comprising CE 1100 pump, CE 1200 variable wavelength monitor, CE 1300 gradient programmer, CE 1400 refractive index detector, CE 1500 electrochemical detector, CE 1700 computing integrator, CE 1710 recorder and 1720 recorder, CE 1800 sample injector, 1200, 2000 column monitoring panel and sample valve. 

Model RR/066 351 and 352 pumps models 750/16 variable-wavelength UV monitor detector 750/11 variable filter UV detector, MPD 880S multiwave plasma detector, 750/14 mass detector 750/350/06 electrochemical detector refractive index detector HPLC columns column heaters, autosamplers, pre-columns derivatization systems, solvent degassers, preparative HPLC systems... 

FIGURE 13.8 The HPLC variable-wavelength UV detector—a UV spectrophotometer with a flow cell. A peak appears when a mixture component that absorbs the set wavelength elutes from the column. 

Distinguish between the fixed-wavelength UV detector and the variable-wavelength UV detector in terms of design and use. 

Fig. 38. LS plots31) for high molecular weight polystyrene (M = 2.8 x 106) at a fixed angle (90°) and variable wavelength...

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