3.2. ICP-AES analysis of waste water
Experiments showed that no preliminarily sample
preparation was necessary except for addition
of HNO3 to adjust the pH to 4.5. Waste water
samples (500 ml) from a non-ferrous metallurgical
plant near Plovdiv were analysed by the proposed
procedure. The results are presented in Table 4.
They are in good agreement with that obtained by
the reference ICP-MS method.