Concentration of selected heavy metals in spices, dry fruits and plant nuts.

Different spices, dry fruits and plant nuts commonly consumed in Pakistan were assayed for the heavy metals cadmium, lead, copper, zinc, iron and manganese by the potentiometric stripping analysis and AA spectrophotometry. The results revealed wide variation in heavy metal content among different biological materials. Mixed spices generally exhibited higher value for trace metals specially lead (6.6-9.2 micrograms/g), cadmium (0.65-1.34 micrograms/g), iron (142.3-285.0 micrograms/g) and zinc (64.2-65.8 micrograms/g). Dry fruits contained relatively lesser amounts of heavy metals than plant nuts. Almonds contained higher levels of lead (1.02 micrograms/g) and cadmium (0.24 micrograms/g) than other nuts and dry fruits.