Absorbance or light scattering

Absorbers or light scatterers to reduce light absorption by the impurities in the polymer. 

The absorbance or light scattering properties of a microbial culture are related to... 

Compound purity or integrity testing using methods such as UV absorbance, evaporative light scattering, MS, NMR, etc.25... 

Protein content, particularly in urine or cerebrospinal fluid, may also be estimated by methods based on precipitation using sulfosalicylic acid (an anionic protein precipitant) or heat. The turbidity, which is a measure of protein concentration, can be quantitated by spectropho-tometric absorbance methods or light scattering analysis. Absorbance of a hydrophobic indicator dye that binds to protein and changes color is also used. 

Molecular absorption or light scatter can be corrected for by several methods. If the interfering salt composition is known, it may be possible simply to add the salt or salts to standards and make a direct comparison with calibration curves. It is relatively simple to measure the background absorbance. One way is to choose a nonresonance line from the lead hollow cathode lamp or another lamp that is not absorbed by lead and which occurs at least two bandpasses from the resonance... 

Optical Probe. Optical probes can also be used to measure solid concentration and are generally of two types light absorption or light scattering. In both cases the amount of light absorbed or scattered is related to the solids concentration. For absorption. Beer s law applies ... 

One must wash the porous solid with pure solvent to eliminate all free particles. Then one can either measure in terms of density or UV absorbance. It may also be possible to use various diffraction methods (neutrons, X-rays or light scattering). 

Turbidimetry and Nephelometry. In contrast to classical absorbance methods, immunoassay reactions frequently involve agglutination in which the optical scatter signal of the agglutinated particles is measured by turbidimetric or nephelometric means. The principles of light scattering as it relates to analytical methods is discussed in reference 6. 

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