Furthermore, the concentration-dependent inhibitory effect of heavy metal ions on RNase A was observed using the method and the results indicated that Ba2+, Co2+, Pb2+, As3+, and Cu2+ inhibited RNase A activity with IC50 values of 93.7 μM (Ba2+), 90.9 μM (Co2+), 110.6 μM (Pb2+), 171.5 μM (As3+), and 165.1 μM (Cu2+), respectively. 
THERM