Minimum wavelength

Yoshimura et al. [193] carried out microdeterminations of phosphate by gel-phase colorimetry with molybdenum blue. In this method phosphate reacted with molybdate in acidic conditions to produce 12-phosphomolybdate. The blue species of phosphomolybdate were reduced by ascorbic acid in the presence of antimonyl ions and adsorbed on to Sephadex G-25 gel beads. Attenuation at 836 and 416 nm (adsorption maximum and minimum wavelengths) was measured, and the difference was used to determine trace levels of phosphate. The effect of nitrate, sulfate, silicic acid, arsenate, aluminium, titanium, iron, manganese, copper, and humic acid on the determination were examined. 

Fig. 3.19a Solar spectral irradiance (global AM 1.5) and the fraction of the irradiance above A,niin where A,niin is the minimum wavelength at which the spectral irradiance has a measurable value [101],...

In an X-ray tube where electrons are accelerated by a potential of 5000 V, the minimum wavelength of X-rays produced is found to be 248 pm. Explain why this is, and estimate a value for Planck s constant. 

Zero-order first and second derivative UV absorption spectra of 18 purines and pyrimidines were determined in aqueous solution at 298 K. The procedure, based on the direct comparison of the derived maximum and minimum wavelengths and of the sequences of relative amplitudes, can be used for concentrations of purines as low as 5 x 10-6 M <85MI 7li-0l>. A similar study has shown that second derivative spectra can be used for the identification of eight mixtures of purines and pyrimidines <88TAL513>. The structure and equilibrium of purine in ethanol has been studied by UV spectroscopy which indicates the existence of annular automery in purine and the presence of associated species of only one of its tautomers <88JST(174)83>. Both polarized UV and Raman... 

Minimum Wavelength for Common Solvents Used In UV Spectroscopy ... 

In this laboratory apparatus has been constructed to examine the photodegradation of polycarbonate with simultaneous control of the following variables l) minimum wavelength of light, 2) oxygen or nitrogen atmospheres, 3) relative humidity, and 4) state of prior hydrolysis of the sample. In addition, the temperature is controlled at 22-25 "C. 

Minimum Wavelength (nm) ATM. Time (hr.) (xlO3) m Low-molecular-wt products ... 

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