Nephelometry
The nephelometry ( Greek. Νέφος nephos , cloud 'and μέτρον métron , dimension'), or tyndallometry , an optical analysis method with which a finely distributed over the quantitative concentration of colloidal particles in liquids or gases can determine the haze. The instrument used for the analysis is a nephelometer , the result will in Nephelometric Turbidity Units (NTU) (engl. For nephelometric turbidity units ) indicated.
If a suspension of small particles is placed in a light beam, part of the light that has entered is absorbed , while part is scattered to the side of the incoming beam (the side scattering is based on the Tyndall effect ).
With nephelometry, the scattered light emerging from the side is measured, with turbidimetry, on the other hand, the scattering-related reduction in the intensity of the light beam passing through the liquid . The latter is not to be confused with photometry , in which absorption processes are responsible. Turbidimetry is still used routinely today to determine lipase activity. Laser nephelometry is mainly used for the quantification of immunologically determinable serum components (by means of antigen-antibody reactions ).
Individual evidence
- ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, pp. 931-932.