Detection of Castor Oil Purity by Measuring Optical Rotation Using a Polarimeter

Abstract

Polarimeter is a device that uses the principle of polarization, ie a beam that is passed by the polarizer in various forms of polarized light. The polarized beam can be shaped linear polarization, circular polarization and elliptical polarization. Polarized light beam that has been passed to the analyzer. Analyzer is the recipient of a polarized light beam from the polarizer. Polarimeter in organic chemistry can be used as a tool to determine the optical rotation, concentration and composition of optical isomers in a solution or mixture rasemik. Castor oil is a vegetable oil obtained from Jatropha seed extraction (ricinus communis), in the field of pharmaceuticals is also known as castor oil. Gasoline is a non-polar solvent that dissolves the most perfect for a variety of oils including castor oil, and therefore gasoline is a solvent used in the lab this polarimeter. Practicum with a polarimeter performed by using a variable that is fixed castor oil 10 ml and 20 ml of castor oil as well as variables that change with the addition of gasoline each 1 ml, 2 ml, 3 ml, and 4 ml for kurvet I, while for kurvet II added each 2 ml, 4 ml, 6 ml and 8 ml. To kurvet I in one variable has an optical rotation of 104.5 °, then the second variable optical rotation of 103 °, a third variable that has an optical rotation of 100.5 °, all four variables had an optical rotation of 98.5, while the fifth has a variable optical rotation of 95 ° . To kurvet II on one variable has an optical rotation of 108 °, then the second variable has an optical rotation of 106.5 °, the third variable has an optical rotation of 105 °, the fourth variable optical rotation of 102.5 °, while the fifth has a variable optical rotation of 100.5 °