0) 



0) 

 Q. 



0.020 



0.016 — 



2 



2 0.012 



c 

 o 



i_ 

 c 



G) 

 O 



c 

 o 

 O 



0.008 



0.004 



0.000 



As 



Pb 



B 



Ni 



Cd Se 



Cr Zn 



Cu 



