QC2C: OTHER INSTRUMENTAL METHODS

- Livy

Polarimetry

The measurement of optical rotation or optical activity of a substance determining if a drugs is active depending on isomer.

Polarized light

one direction light from the polarizer

Chiral

Substances that may show optical rotatory power

Optically Active

Substances rotates planet polarized light to the left or to the right

Sucrose at 65.9 degrees

Standard used in Polarimetry

Polarimeter

Measures the extent to which a substance interacts with plane polarized light (light at which consists of waves that vibrate only in one plane)

Specific Rotation of a Liquid

Defined as the angular rotation in degrees through which the plane polarization of polarized monochromatic light is rotated by passage

25 C

Temperature specified in official standards for the measurements of optical activity is ——-

light source, polarizer, sample compartment, analyzer, detector

parts of polarimeter

Refractometry

valuable in the identification of a substance and the detection of impurities and a technique that measures how light is refracted when it passes through a given substance (an unknown compound) and the amount by which the light is refracted determined the Refracted Index (RI)

Refractive Index

_____ of a substance is the ratio of the velocity of light in air to the velocity of light in a substance; the amount of light refracted

25 C

temperature for refractive index

Refractometer

An instrument by Ernst Abbe designed in 1689 which can be used with ordinary white light.

Water

Reference standard of refractive index

1.3325

RF of water at 25C

1.00029294

absolute RI of air

Water Jacket

a part of refractometer for the control of temperature

Refracting prism assembly with illuminator

most important part of refractometer

Hinged lightshield

part of refractometer used to trap light, protect the prism and cover the lower and upper prism case

eyepiece, measurement scale, dual reticle and total reflection borderline

parts of the internal measurement scale

Temperature Compartment

part of refractometer that records the temperature

Compensating Prism System

the part of the refractometer that functions to adjust the calibration

Percentage Brix

a quantitaive measurement that is capable of measuring sugar

Potentiometry

Branch of electrochemistry which deals with the study and measurement of electrode potential

Electrochemical cells

the potential difference between the cathode electrode potential and the anode electrode potential is the potential of the ________

Glass Electrode

The most popular of all indicator for pH determinations

pH meter

Potentiometric method gives the pH values using commercially available _____

Chloride

the most common ion used in pH meter

Iodine

selective electrodes used in water determination