Trace and ultratrace analysis:
The accuracy, precision and detection limits of flame AAS depend on how the analyte sample is introduced into the atomiser. We need to transfer a reproducible and representative portion of a sample into an atomiser which depends on the physical and chemical state of the analyte and the sample matrix. The sample introduction is achieved with the help of a nebuliser. The generally used nebulisation techniques are ultrasonic nebulisation, pneumatic nebulisation, electrothermal vaporisation and hydride generation.
Atomic absorption spectrophotometry (AAS) is now a routinely and widely employed technique for trace and ultratrace analysis of complex matrices of geological, biological, glass, environmental, industrial, cement, marine sediment, pharmaceutical, engine oil or any other kind of samples. An atomic absorption techniques using flame are rapid and precise and are applicable to about 67 elements. The electrothermal methods of analysis instaed are slower and less precise; thus, these are more sensitive and require much smaller samples.