Atomic absorption spectrophotometer is widely used for the determination of heavy metals and some cations in environmental analysis. The source of radiation is a HOLLOW LAMP, which contains the cathode of some metals as being analyzed. They emits the wavelength characteristics of the metal, and a different lamp is required for each metal. The light from the lamp is required for each metal. The light from the lamp is directed to a flame and onto a monochromator, which selects the preferred analytical wavelength. The light is monochromator is detected by a photomultiplier tube and converted to an electrical signal. The sample is aspirated in the flame where the solution is evaporated and the metal containing compounds are volatilized and dissociated into ground state atoms. The ground state atoms absorbs the radiation from the hallow lamp and excited to higher energy levels. Some atoms are also thermally excited but their fraction is so small that it causes no error in the analysis. An acetylene-air flame is used....ORIGINALLY WRITTEN BY FREEVIBES.COM.NG
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