Absorption ratio

It is seen that the profile of the combined peaks is perfectly symmetrical and displays no hint that there are two solutes present. Obviously an absorption ratio curve from a diode array detector would quickly disclose the presence of the two components, as would an appropriate changes in mobile phase composition. However, there would be a further clue for the analyst to follow that would give warning of the "duplicity" of the peak. The double peak would be very broad and be inconsistent with the change in peak width of the other solute peaks with retention time. The peak width of a solute increases regularly with retention time but, unfortunately, the relationship is not smooth. There are good reasons for this, but they... 

Absorption Ratio, Differential—Ratio of concentration of a nuclide in a given organ or tissue to the concentration that would be obtained if the same administered quantity of this nuclide were uniformly distributed throughout the body. 

A number of UV-vis absorption ratios have been measured to provide information about the state of humification and content of humic material in the dissolved organic carbon (DOC). For example, the ratio of the ultraviolet absorbance at 254 nm (UV254) with the DOC content provides an estimate of the abundance of ultraviolet absorbing species and may also be used for comparison of the aromaticity of various humic materials (McDonald et al., 2004). 

Absorbance spectra monolayer on mica, 244/ thickness of mica sheet, 241 Absorptivity ratios, definition, 28 Acyl chains, monolayer films, 198 Adatom(s) definition, 210 surface migration, 211214... 

For all the above reasons, it is to be preferred to measure two solute properties in one detector, especially if both measurements can be performed simultaneously. An example of this is the application of dual-wavelength absorption detection in LC. The application of this technique for the purpose of selectivity optimization has been investigated by Drouen et al. [584]. For the purpose of peak assignment or recognition, ratio recording may be used. The principle of this technique is based on Beer s law and may be explained from the following equation for the absorption ratio Ra ... 

Absorption Ratio Hard segment Soft segment Substrate Side... 

Table II. Absorption Ratios of Biomer Film Surfaces (19)...

The structure elucidation of 34 was based, in principle, on two facts color reactions and hydrolysis. Compound 34 does not react with ninhydrin (therefore, no primary amino group is present) but it does react with l-fluoro-2,4-dinitrobenzene. By exact determination of the absorption ratio E35O/E390 after the reaction with the latter reagent, Tait concluded that 34 contains a secondary amino group (50). Hydrolysis (6 N HC1, 110°C, 24 hr) of the so-called compound II afforded 2,3-dihydroxybenzoic acid and spermidine (50). The presence of two 2,3-dihydroxybenzoyl residues in 34 was demonstrated by its enzymatic (50) and chemical synthesis (51-54). 

The selection of appropriate wavelengths and the use of accurate absorptivity values are clearly crucial. Generally A is the A for component 1, while A is the A for component 2, provided that at these wavelengths the absorptivity of the overlapping component is small. If the spectra of both components are very similar, the errors of the method increase appreciably as the difference between the absorptivity ratios tends to zero. 

Further evidence can be deduced from the absorptivity ratios of peaks within a spectrum moreover, the change in these ratios together with the shift in peak positions as the pH is changed can be diagnostic. If a drug molecule ionises reversibly (i.e. without degradation), the family of curves for a constant concentration in acidic and basic solvents will display one or more isosbestic points at characteristic wavelengths, where the absorb-ance is constant at all values of pH. 

It is seen that the separation appears to be satisfactory and all the peaks represent individual solutes. Furthermore, without further evidence, it would be reasonable to assume that all the peaks were pure. However, by plotting the adsorption ratio, 250 nm/255 nm, for the anthracene peak it becomes clear that the peak tail contains an impurity as the clean rectangular shape of the other peaks is not realized. The absorption ratio peaks are shown in figure 10. 

Considering the analogical inference, we can consider here the black body, which is perfectly black at normal temperature. (Soot has almost the same nature with the black body, and has an absorption ratio of 95% ) The intensity of the radiation from the black body increases only with the temperature, and it changes the colour from black to red, orange, white as the temperature increases. The colour is determined by the temperature only, and is shown by the M curve on the chromaticity diagram(Fig.35) ... 

Finne U, Salivirta J, Urtti A. Sodium acetate improves the ocular/ systemic absorption ratio of timolol applied ocularly in monoisopropyl PVM-MA matrices. Int J Pharm 1991 75 Rl—R4. 

Figure 1. IR absorption ratios for O, low conversion and high conversion...

Before bending tests, all specimens were ground to make the surfaces smooth and to have the same thickness. All specimens were dried at 105 degree Cels, for 48 hours. Water absorption ratio was measured by the difference of weight before and after drying only in the case water curing. 

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