flame atomic absorption spectroscopy Flashcards
How can absorption and emission of radiation be explained?
By considering radiation as a stream of particles called photons or quanta
what state must electrons be in when absorption is observed?
ground state
what state must electrons be in when emission occurs?
from a higher level - doesnt always return to ground state
what does this lead to?
more emission lines than absorption lines
what are spectral line widths?
narrow spread of wavelengths over which absorption and emission is observed for a given electronic transition
What 3 factors can affect line widths?
natural line width, doppler broadening, pressure broadening
why is the narrowness a distinct advantage? 2
reduces spectral overlap and makes atomic spectroscopy very specific and sensitive
give examples of applications of FAS
trace metals in blood, toxic metals in industrial waste, elemental impurities in oil
what kind of information does this technique provide you with?
elemental composition of samples, no info on molecular composition
what is the simplest method of converting ions and molecules into atoms in atomic spectroscopy?
flame
What is the main factor that affects the process?
Flame temp
after creating a calibration graph of data and calculating the slope, m and intercept c, what can the slope be used to determine?
molar absorptivity
