Question

the flame side of the AA measures concentration in parts per million range and the furnace side of the AA measures in parts per billion. what is the major difference in terms of sample introduction and electron excitation for these two kinds of spectroscopy?

I am in desperate need of help!!! It would be amazing if someone were to answer this in a way where it makes sense.

Answer 1

For the Atomic Absorption,it can be chiefly measured via two routes-1)Flame Atomic Absorption Spectroscopy and 2) Graphite Furnace Atomic Absorption Spectroscopy.The flameside AA concentration measurements are done in Parts per Million while in Furnace AA it is measured in Parts per Billion.

The major difference between Flame AA and Furnace AA is Graphite Furnace analysis is that required time islonger than those for Flame sampling, and fewer elements can be determined using GFAA.Also the sensitivity and detection power through Furnace AA is much higher than Flame AA as atomized species stay for longer period in the tube.

In terms of Flame AA spectroscopy Atomic Absorption (AA) happens when a ground state atom absorbs energy in the form of light of a specific wavelength and is pushed to an excited state. The amount of the light energy absorbed in this wavelength will increase as the number of atoms of the selected element in the light path increases.While in Furance AA spectroscopy the sample is introduced directly into a graphite tube, which is then heated until all the sample is atomozed and all the atoms are retained in the tube for longer period of time and it becomes easy to detect very trace species which are in very minute amount in analyte.That's why Furnace AA can measures concentration in parts per billion.