As plane-polarized light goes through some substances their plane of polarization
spatial orientation changes (turns on some angle). Such substances are called optically active substances. Some crystals (quartz, vermilion, etc.), pure liquids (turpentine, nicotine, etc.), solutions of some substances (sugar, vinic acid, etc.), some gases (camphor vapor) – are optically active substances. All important biological molecules (proteins, nucleic acids, vitamins, polysaccharids, etc.) are optically active. The law of plane of polarization turn was stated for solutions. Plane of polarization turning angle φ depends on optically active substance concentration in solution С & light path length in solution L: φ = аСL,
Polarimetry
а – is called specific turning coefficient.
This equation is the base of Polarimetry– the method of solution examination. Thanks to this method the concentration of substances in solution can be defined. Polarimetry is also used in molecular biophysics for molecular structure transformation research. One of the most important examples of polarized light using is polarimetry microscope. Some tissues (i.e. muscle, bone and nerve tissues) are optically active and only they can be seen in polarization microscope during examination. During examination on polarization microscope only objects which turn plate of polarization can be seen.
A box with
solution
L
Rieznyk