The role of trace and toxic levels of elements in human
health has become an important area of scientific research.
Lead and cadmium constitute the highest environmental
hazard due to their extensive use, toxicity and widespread
distribution. Heavy metals are non-degradable and so they
accumulate in the environment.1–2 The advent of atomic
absorption techniques provided more accurate determination
of low levels of metals in human body fluids and
other complex matrices. Graphite furnace atomic absorption
spectrometry seems to be the most suitable technique
for trace determination of metal ions because of its
excellent sensitivity, relatively simple operation, and low
consumption of samples. However, it is an expensive
analytical method and suffers from matrix interference.
Flame atomic absorption spectrometry is often applied
because of its speed and ease of operation, but it has the
major drawback of low sensitivity for direct determination
of low levels of heavy metals. Therefore, preconcentration
and matrix elimination steps are required for
ultra trace determination of elements.3 Among different
automated techniques for the determination of trace metals
in a complex matrix, flow injection analysis (FIA)