Theoretical absorbance

Using the extinction coefficients given above, the example for p-carotene, a 1 % solution (1 g/100 ml or 10 mg/ml) would give a theoretical absorbance reading of 2592 AU. A 2 pg/ml solution should therefore give an absorbance reading of 0.518 AU however, as indicated earlier, the standard solution must be... 

Figure 3. Theoretical absorbance for a monolayer at the A/W interface plotted as a function of the experimental angle of incidence of the incoming radiation. The solid line indicates the theoretical absorbance for s-polarized radiation the dashed line indicates the theoretical absorbance for p-polarized radiation.

C. Prepare a STOCK solution of0.9350 g/L K2Cr207 in 0.005 mol/L H2S04. This solution has a theoretical absorbance (A) of 10.0 at 350nm. Stable indefinitely in a well-stoppered, pyrex glass container. 

For electrolyses involving time scales shorter than about 500 /is, the diffusion layer is of the same order as S, and the absorbance is sensitive to the evolving concentration profile of R (6, 46, 47). The resulting optical transients can be useful for characterizing rather fast electrochemical processes, which are otherwise complicated severely by nonfaradaic contributions to current and charge functions. Theoretical absorbance transients can be computed from (17.1.13), once the diffusion-kinetic equations defining the concentration profile of R have been solved, either analytically or by numeric methods such as digital simulation. 

Neglecting photon shot noise and dark counts, the lowest theoretical absorbance (A) measurable on a 16-bit camera can be calculated using the Beer-Lambert law ... 

Figure 11. Theoretical absorbance vs. time profiles at various diffraction angles. Chromophore ( = 10,750) was generated from 1.2 X 10 3 M of a colorless precursor, at an electrode with 0.5 itm path length along the optical axis (Beer s law absorbance = 0.65). The diffusion coefficient was 1.5 X 10"5 cm2/sec and the laser wavelength was 632.8 nm.

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