4: Atomic Absorption Spectrometry (AAS) Check Access

This chapter discusses the use of flame and electrothermal atomic absorption spectrometry. It starts with a section equally applicable to many other techniques. The importance of standard preparation and calibration of the tools used, i.e. analytical balances and pipettes as well as ensuring that the stock standards used are commensurate with previous stock standards, is emphasised. The advantages and disadvantages of flame AAS are discussed along with useful hints and tips to assist the analyst. These include the use of less sensitive wavelengths to reduce the requirement of diluting numerous samples, rotating the burner head slightly to extend linear range, etc. Optimisation of the operating conditions ensuring maximal sensitivity is obtained is also discussed. The electrothermal atomization section also discusses the optimization protocols (ash/atomize curves) used when minimising interferences and maximising accuracy. The advantages and disadvantages of the technique are also provided. The hints and tips section covers the use of matrix modifiers and recommends consultation of the manufacturer’s handbook as this normally gives optimal conditions to use for the majority of sample types. A section on data analysis, emphasising the necessity to ensure that replicate analyses are precise, ensuring that periodic check standards are stable, etc. is provided.