PHYSPHAR-LAB (dragged) 2.pdf

CYCLE SEM Physical Pharmacy LAB PHARM3A | TUTOR 1 1 MODULE 3: REFRACTIVE INDEX DETERMINATION OF VOLATILE OI...

CYCLE SEM Physical Pharmacy LAB PHARM3A | TUTOR 1 1 MODULE 3: REFRACTIVE INDEX DETERMINATION OF VOLATILE OILS REFRACTIVE INDEX Refractometer Refractive Index Apparatus used to determine refractive index Index of Refraction used for basic determination: Physical constant used in the identification o Refractive index and detection of impurities in volatile oils of a o Dispersive value transparent substance is the ratio of the o Brix percentage velocity of light in air to its velocity in the Used for applied determination: material. Sin Li / Sin Lr o Purity o Angle of Incidence – Angle between o Viscosity the ray in the first medium o Specific gravity o Angle of Refraction – corresponding o Mixing ratio angle on the second medium o Rxn tracing A value calculated from the ratio of the speed o Polymerization of light in a vacuum to that in a second o Properties medium of greater density. o Ripeness The refractive index variable is most commonly symbolized by the letter n or n' in ABBE REFRACTOMETER descriptive text and mathematical equations. In Optics a dimensionless number that describes how fast light travels through the material. It is defined as: n = c / v o where c is the speed of light in vacuum and v is the phase velocity of light in the medium. For example, the refractive index of water is 1.333, meaning that light travels 1.333 times ATAGO REFRACTOMETER as fast in vacuum as in water. Increasing refractive index corresponds to decreasing speed of light in the material. Refraction of a Light Ray Portable Refractometer RA 130 Kem Kyoto Electronics Manufacturing Co. Ltd. AD | PHARMACY 2A | 2021 1  MODULE 3: REFRACTIVE INDEX DETERMINATION OF VOLATILE OILS POST LAB DISCUSSION SAMPLE STANDARD REFRACRIVE INDEX ANISE OIL 1.5530 – 1.5600 LEMON OIL 1.4742 – 1.4750 PEPPERMINT OIL 1.4590 – 1.4755 EUCALYPTUS OIL 1.4580 – 1.4700 ROSEMARY OIL 1.4570 – 1.4630 SPEARMINT OIL 1.4840 – 1.4910 LAVENDER OIL 1.4590 – 1.4700 ROSE OIL 1.4570 – 1.4630 BERGAMOT OIL 1.4640 – 1.4690 ORANGE OIL 1.4720 – 1.4740 AD | PHARMACY 2A | 2021 2