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 Atomic
Absorption Spectrometry (AAS) - The
AAS method is absorption analysis (as opposed to emission analysis). Various sample
weights and acid mixtures are used in digesting the samples. The elements in solution
are vaporized into an acetylene flame. The atoms of the element in the flame absorb
light. The analysis is performed by the measurement of the amount of this light
that is absorbed by the sample. The monochromatic light source used is selected
to match an absorption line of the element of interest. The monochromatic light
source used produces a wavelength of light that precisely matches the absorption
line of the element of interest. AAS is capable of achieving ppm values for most
elements. AAS analysis can only accurately be done one element at a time.
Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) - The
ICP-OES method is an attractive technique for multielement analysis. The procedure
involves digesting a variety of sample weights using various acid combinations
and vaporizing them into an extremely high-energy argon plasma. Energy is absorbed
by the elements in the sample as they pass through the middle of plasma. As the
sample leaves the plasma, the excited elements return to 'ground state'. In doing
so they emit energy in the form of light. Each element emits light at several
different wavelengths. One of these wavelengths is isolated for each element and
the intensity of light at that wavelength is measured. The intensity of the light
measured is proportional to the concentration of that element in the sample. Most
elements of interest have acceptable sensitivity using this technique.
TSL Laboratories offers a variety of packages involving AAS and ICP methods. Please
refer to our Fee Schedule for the appropriate package. As well, you can contact our client
services group to help you decide on the appropriate method for your project. |
