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:
“In child rearing it would unquestionably be easier if a child were to do something because we say so. The authoritarian method does expedite things, but it does not produce independent functioning. If a child has not mastered the underlying principles of human interactions and merely conforms out of coercion or conditioning, he has no tools to use, no resources to apply in the next situation that confronts him.”
—Elaine Heffner (20th century)
“I suppose that one of the psychological principles of advertising is to so hammer the name of your product into the mind of the timid buyer that when he is confronted with a brusk demand for an order he can’t think of anything else to say, whether he wants it or not.”
—Robert Benchley (1889–1945)
“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)