چکیده (انگلیسی):

This work assessed levels of heavy metals exposure from silver coatings of mobile
phones recharge cards of three major companies (designated as A, B and C) with price
denominations 100, 200 and 400 from companies A, B and C respectively,
which were carefully scratched using a plastic scraper into a glass tube. The coatings
were acid digested for total metal concentration, while speciation experiment for Mn,
Cu, Cd and Pb was carried out. Total metals and speciation analysis were done using
AAS and XRF techniques. The total metal concentration from XRF analysis was in the
range: Ca (70–2140 g/g), K (20–4930 g/g), Sc (80–270 g/g), Ti (1530–12,580 g/g),
Fe (50–6660 g/g), Ni (20–2040 g/g), Cu (20–850 g/g) and Zn (40–460 g/g). Cr had
the lowest concentration (10 g/g) in A ( 400) while Ti had the highest concentration
(12,580 g/g) in C ( 500) for all the coatings analyzed. AAS and XRF results agreed closely
except for Fe with higher concentration. A ( 100) contained high concentration of the
metals compared with others. Speciation study identified Mn as the most mobile element
when present in the environment.