The emphasis on the removal of toxic metal ions has
led to a considerable growth in the development of new
methods in analytical chemistry for extraction, separation
and determination of various metal ions. Accurate and precise
analyses of trace heavy metal ions by instrumental
analysis techniques including inductively coupled plasmamass
spectrometry (ICP-MS), inductively coupled plasmaatomic
emission spectrometry (ICP-AES), flame atomic
absorption spectrometry (FAAS), etc., are an important
part of analytical chemistry1-4 because ecological and health
problems associated with environmental contamination
continue to rise. The direct determination of the trace metals
in solid or powder sample solutions with a complicated
matrix by atomic spectroscopic methods, such as flame
atomic absorption spectrometry (FAAS) and inductively
coupled plasma atomic emission spectrometry (ICP-AES)
is often difficult due to their extremely low concentrations
and matrix interferences; therefore, a preconcentration
method is required.5-8