A polarimeter is a laboratory instrument used for measuring the rotation of polarized light that passes through a sample. This instrument is commonly used in pharmaceutical, chemical, and food industries to measure the concentration and purity of chiral compounds, which are compounds that exist in two enantiomeric forms that have different optical activities.
A polarimeter works by passing a beam of polarized light through a sample and measuring the rotation of the plane of polarization as it passes through the sample. The amount of rotation is proportional to the concentration and specific rotation of the chiral compound in the sample. The specific rotation is a unique value for each enantiomer and is measured in degrees per unit concentration per unit path length.
Polarimeters come in two main types: manual and automatic. Manual polarimeters are simple and low cost and are suitable for most laboratory applications. Automatic polarimeters use advanced technology, such as digital signal processing and touch screen displays, to provide more accurate and efficient measurements.
Polarimeters are also available in different sizes and configurations, including benchtop and portable models. Benchtop polarimeters are large and suitable for high-throughput laboratories, while portable polarimeters are compact and convenient for field applications.
Overall, polarimeters are essential laboratory instruments that enable scientists to identify and quantify chiral compounds in a range of applications.