Turbidity measurements can be performed with an absorbance instrument that measures light transmission through a sample. The more turbid a sample is, the less amount of light will pass through the sample. This relationship is directly proportional in a linear fashion and can be used to determine the degree of turbidity of a sample, i.e. the amount of insoluble particles in solution. However, this linear relationship only occurs to a certain degree of turbidity. For most absorbance instruments, the turbidity measurements deviate from a direct linear relationship usually above 3 O.D., that is when only 1 photon of light in 1,000 is transmitted through the sample. BMG LABTECH microplate readers that can perform turbidity absorbance measurements are: SPECTROstar, FLUOstar, and POLARstar Omegas; FLUOstar and POLARstar OPTIMAS; SPECTROstar Nano; as well as the PHERAstar Plus and PHERAstar FS.
|Fig 1. Light-scattering can be used to measure the turbidity of a sample.|
|Fig. 2: Solubility diagram of CD-Econazole-nitrate complex |