The environmental pollution can cause increased levels of toxic
elements in foods, which results in detrimental effects on human
health. Moreover, some of the metals are the subject of food and
drug legislation. For instance, according to the regulations of
Hong Kong government, the maximum allowed concentration of
As, Hg and Pb in many herbs is 2, 0.2 and 5 lg g1, respectively.
Thus, the determination of toxic elements in herbs is important
as a quality check. ICP-MS has been applied for the determination
of trace elements in various food and herb samples