Direct polarography has been used to determine lead in soil. Potentiometric stripping methods have been used to determine copper and lead in non-saline sediments, lead in saline sediments and copper and lead in sewages. Program-controlled automatic switching and mixing of these three electrode configurations during a single analysis via software commands occur. The standard addition method (SAM) is the procedure generally employed to calculate the analyte content from the signal of the sample solution; electric current SAM amount of substance/mass concentration. The SAM is coupled directly to the determination of the sample solution so that all factors which influence the measurement remain constant. Spectrofluorimetric methods are applicable to the determination of lead and selenium in soils and non-saline sediments, thorium and uranium in non-saline sediments, mercury in marine sediments and cadmium in sludges. Non-specific background attenuation has always been the most common type of interference in graphite furnace atomic absorption spectrometry.