Sensitivity in atomic absorption

Ramirez-Munoz, J., N. Shifrin, and A. Hell Quantitative Sensitivity in Atomic-Absorption Spectroscopy. Microchem. J. 11, 204 (1966). 

Sensitivity in atomic absorption is conventionally defined using the gradient of the calibration line for each element. In flame atomic absorption, it is expressed in terms of the concentration level of the clement (microgram per millilitre) producing an absorption of 1%, i.e. a relative absorbance of 0.0044. The sensitivity defined in this way essentially depends on the atomisation conditions geometry of the burner, equilibrium reactions, etc. 

What causes the red feather in a reducing nitrous oxide-acetylene flame Explain why electrothermal atomizers result in greatly enhanced sensitivity in atomic absorption spectrophotometry. 

Sensitivity, in atomic absorption, is a measure of the amount of absorption produced by a given sample concentration and is generally given as p.p.m./l% absorption. Detection limit is defined in various ways to represent the minimum sample concentration which it is possible to distinguish from zero. The most common misconception is the belief that an increase in sensitivity—Le., higher absorption for the same concentration—automatically produces an improved detection limit. This is by no means true since the detection limit depends also on the stability and freedom from fluctuation of the signal produced. 

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