A flame atomic absorption spectrometer (Solaar M6 TJA Solutions)
with deuterium background correction, equipped with a hollow
cathode lamp was used for determination of Cd, Cu, Ni, Pb, and
Zn. An air-acetylene burner was used. The wavelengths (spectral
band pass) were as follows: for Cd: 228.8 nm (0.5 nm), Cu: