ANALYTICAL METHODS AND INSTRUMENTATION Flashcards
LIGHT WAVES THEORY:
> The light was made up of tiny particles
> The light moves in a straight direction in a vacuum.
ISAAC NEWTON
LIGHT WAVES THEORY:
> Described as photons of energy travelling in waves
> Planck’s formula: E=hv; E= is the energy of a photon in Joules, h= constant (6.626 x 10^34 erg sec)
ELECTROMAGNETIC RADIATION
LIGHT WAVES THEORY:
> Proposed a wave theory of light. Particles of light move in a wave-like manner
CHRISTIAN HUYGENS
TRANSMITTED VIA ELECTROMAGNETIC WAVES THAT ARE CHARACTERIZED BY THEIR FREQUENCY AND WAVELENGTH
ENERGY
THE DISTANCE BETWEEN TWO SUCCESSIVE PEAKS
WAVELENGTH
DISCRETE PACKETS OF ENERGY OR PARTICLES
PHOTONS
THE NUMBER OF VIBRATIONS OF WAVE MOTION PER SECOND
FREQUENCY
WHEN WAVES CHANGES DIRECTION BECAUSE IT BOUNCES OFF A SURFACE
REFLECTION
BENDING OF A RAY WHEN IT PASSES AT AN ANGLE FROM ONE MEDIUM INTO ANOTHER IN WHICH ITS SPEED IS DIFFERENT
REFRACTION
LIGHT ENCOUNTERS A SMALL PARTICLE THE ELECTROMAGENTIC FIELDS CREATED BY THE MOTION OF THE PARTICLE’S ELECTRON MAKES THE LIGHT CHANGES DIRECTION
SCATTERING
DECREASING WAVELENGTH
INCREASING FREQUENCY
THE LOWER THE WAVE FREQUENCY
THE LONGER THE WAVELENGTH
STATES THAT THE CONCENTRATION OF A SUBSTANCE IS DIRECTLY PROPORTIONAL TO THE AMOUNT OF LIGHT ABSORBED OR INVERSELY PROPORTIONAL TO THE LOGARITHM OF THE TRANSMITTED LIGHT
BEER’S LAW
AMOUNT OF LIGHT ABSORBED.
ABSORBANCE
AMOUNT OF LIGHT TRANSMITTED
TRANSMITTANCE
Involves measurement of the light transmitted by a solution to determine the concentration of the light-absorbing substances in the solution
SPECTROPHOTOMETRY
The device used to measure the wavelengths of the light or the intensity of radiation
SPECTROMETER
Is an analytical instrument that is used to quantitatively measure the transmission or reflection of visible light, UV light, or infrared light.
SPECTROPHOTOMETER
SPECTROPHOTOMETRY:
splits the monochromatic light into two components: one beam passes through sample, and other through a reference solution or blank
DOUBLE BEAM SPECTROPHOTOMETRY
TYPES OF DOUBLE BEAM SPECTROPHOTOMETRY:
with 2 photodetectors, for the sample beam and reference beam
DOUBLE-BEAM IN SPACE
TYPES OF DOUBLE BEAM SPECTROPHOTOMETRY:
1 photodetector; passes the monochromatic light through the sample cuvette then through the reference cuvette
DOUBLE-BEAM IN TIME
SPECTROPHOTOMETRY:
Simplest type of an absorption spectrophotometer.
Designed to make one measurement at a time at one specified wavelength
SINGLE BEAM SPECTROPHOTOMETER
SPECTROPHOTOMETRY:
It provides polychromatic light and must generate sufficient radiant energy or power to measure the analyte of interest
LIGHT/RADIANT SOURCE
TYPES OF LIGHT SOURCE:
emits radiation that changes in intensity; widely used in the laboratory.
CONTINUUM SOURCE
