Powdered detergents defined

Reflectance NIR cells allow rapid analysis of many different materials, but with some loss in precision over transmission measurement. Walling and Dabney have demonstrated the use of a conventional reflectance instrument to measure active agent content and functionality of an alcohol sulfate, as well as concentration of an additive (12). For a well-defined system, the determination of several parameters requires only a very few minutes. A reflectance NIR instrument is also suitable for quality control monitoring of surfactants and other components of powdered detergent formulations (13). NIR reflectance has even been demonstrated for detecting residues of an unspecified detergent on a stainless steel surface, with a detection limit in the 1 pg/cm range and reasonable hnearity down to about the 15 pg/cm level (14). The patent literature describes the use of NIR reflectance to determine the amount of water film left behind on a quartz tube after a surfactant solution has contacted the exterior of the tube. Within limits, the mass of the film is related to the surfactant concentration of the solution (15). 

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