Burners:

Two main types of nebuliser burners used in AAS are premix nebuliser-burner system and total consumption burner. You have learnt about these within the context of flame photometry. You would recall which in premix type burner, liquid is sprayed within a mixing chamber whereas the droplets are mixed along with the combustion gas and are sent to the burner. Figure gives a schematic drawing of such a burner used within AAS.

Instead, in the total consumption burner, the nebuliser and burner are combined. This is also known as turbulent flow burner. Various factors are included in the selection of a burner. Commonly speaking, a premix burner is preferred for atomic absorption work, except while a high burning-velocity flame must be used. Turbulent flow burners are hugely used for atomic emission measurements about that you would learn further.

The flame atomisation method elaborates above is used more frequent than the others. As various as 67 elements could be determined through employing simple, easy to use, equipments based on flame atomisation. It is facilitated through the usage of sharp line light sources that result in the ease and reliability in selection of resonance lines. More so, a method is rapid and provides a precision of as high as ± 0.1 % in a various cases.

Figure: Schematic diagram of premix nebuliser burner system used in AAS