Principles
The technique makes use of absorption spectrometry to assess the concentration of an analyte in a sample. It requires standards with known analyte content to establish the relation between the measured absorbance and the analyte concentration and relies therefore on the Beer-Lambert Law. In short, the electrons of the atoms in the atomizer can be promoted to higher orbitals (excited state) for a short period of time (nanoseconds) by absorbing a defined quantity of energy (radiation of a given wavelength). This amount of energy, i.e., wavelength, is specific to a particular electron transition in a particular element. In general, each wavelength corresponds to only one element, and the width of an absorption line is only of the order of a few picometers (pm), which gives the technique its elemental selectivity. The radiation flux without a sample and with a sample in the atomizer is measured using a detector, and the ratio between the two values (the absorbance) is converted to analyte concentration or mass using the Beer-Lambert Law.
Read more about this topic: Atomic Absorption Spectroscopy
Famous quotes containing the word principles:
“...at this stage in the advancement of women the best policy for them is not to talk much about the abstract principles of women’s rights but to do good work in any job they get, better work if possible than their male colleagues.”
—Virginia Crocheron Gildersleeve (1877–1965)
“The proposition that Muslims are welcome in Britain if, and only if, they stop behaving like Muslims is a doctrine which is incompatible with the principles that guide a free society.”
—Roy Hattersley (b. 1932)
“Language is a process of free creation; its laws and principles are fixed, but the manner in which the principles of generation are used is free and infinitely varied. Even the interpretation and use of words involves a process of free creation.”
—Noam Chomsky (b. 1928)