Polarimetry

• Description

Polarimetry allows us to measure the rotation of the plane of vibration of a polarized light after passing through a solution in which the solute is an optically active substance. 

The value of the angle of rotation depends on the nature of the optically active species, the wavelength of the light used, and the length of the path that the rays travel within the solution. According to the direction of rotation, the substances are classified in dextrorotatory substances, if the angle rotates to the right; and in left-handers substances, if it turns to the left. 

The optical rotation of a pure substance, under specified conditions, provides a fundamental physical constant that is useful for identifying that substance. 

Optical activity is characteristic of many natural products such as amino acids, steroids, alkaloids, and carbohydrates.

• Technology

Polarimeter Perkin Elmer 241MC.

• Applications

• Determination of the specific rotation of a substance [α] λ T 
• Qualitative analysis. If it's a dextrorotatory substance or a left-handed substance 
• Structural determination after chemical reactions. 
• Quantitative analysis from calibration curves 

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