ANALYTICAL METHODS

Distance between two successive peaks and expressed in terms of nanometer (nm)

Infrared region

Visible spectrum

Ultraviolet region

Wavelength is ________________ to Frequency and Energy

Measurement of light intensity in a narrower wavelength

Measurement of light intensity

Involves measurement of light transmitted by a solution to determine the concentration of the light-absorbing substances in the solution

Simplest type of absorption spectrometer Designed to make on measurement at a time at one specified wavelength

Instrument that splits the monochromatic light into two components: 1 beam passes through the sample, 1 beam passes through a reference solution or blank

Function of additional beam

Provides polychromatic light and must generate sufficient radiant energy or power to measure the analyte of interest

Emits radiation that changes in intensity; Widely used in the labroatory Type of Light source

Commonly used light source in the visibule and near infrared region Example of Continuum source

Routinely used to provide UV radiation Example of Continuum source

Produces a continous source of radiation, which covers both the UV & Visible range Example of Continuum source

Emits limited radiation and wavelength Type of Light Source

Also used as light sources for spectrophotometry

Tungsten Light Bulb Mercury Arc

Deuterium lamp Mercury lamp Xenon lamp Hydrogen lamp

Merst glower Globar (Silicone carbide)

Minimizes unwanted or stray light and prevents the entrance of scattered light into the monochromator system

Any wavelengths outside the band transmitted by the monochromator Does not originate from the polychromatic light source Causes Absorbance error

Any wavelengths outside the band transmitted by the monochromator Does not originate from the polychromatic light source Causes Absorbance error