Water
All water samples were fi ltered through
Whatman glass-fi ber fi lters (GF/C). The resulting
extracts were then extracted again with 2%
APDC:MIBK:4N HNO3 (10:10:10, v/v) (Sukasem,
1989). The concentrations of heavy metal in the
fi nal extracts were determined by use of the fl ameatomic
absorption spectrophotometer.