2.1. Apparatus
Lead and cadmium concentration were determined by an AA-
680 Shimadzu (Kyoto, Japan) flame atomic absorption spectrometer
(FAAS) in an air-acetylene flame, according to the user’s manual,
provided by the manufacturer. Lead and cadmium hollow
cathode lamps (HCl) were used as the radiation source with wavelengths
of 283 nm, and 228.8 nm, respectively. The pH was measured
at 25 ± 1 C with a digital WTW Metrohm 827 Ion analyzer
(Herisau, Switzerland) equipped with a combined glass-calomel
electrode.