Apparatus
An atomic absorption spectrometer of the
Perkin Elmer Instruments (USA), model AAnalyst
100 was used for lead determination. A 10 cm long
slot burner head, hallow cathode lamp and
air/acetylene flame were used in this study. A
centrifuge, model EBA20 (Hettich Zentrifugen,
Germany) was used for centrifugation. The pH
measurements were made with a Denver Instrument
pH meter Model 251 (Denver Instrument, USA) with a
combined ATC electrode.