Trace Element Concentration and Speciation in Selected Mining-Contaminated Soils and Water in Willow Creek Floodplain, Colorado
Table 3
Designated partition and chemical reagents used for total extractable and sequential extractionsa.
Partition
Reagents/procedure
Total extractable (TE)
9.0 mL 16 M HNO3 + 3.0 mL 12 M HCl (concentrated); microwave digestion: 180 degrees C for 10 min; made to final 50-mL volume with distilled deionized (DDI) water
(1) Water soluble (WS)
10 mL distilled deionized water H2O; shake 1 h
(2) Exchangeable (EX)
10 mL 0.1 M NaNO3; shake 1 h
(3) Specifically sorbed/carbonate bound (SS/CAR)
10 mL 1 M CH3COONa, adjusted to pH 5 with CH3COOH; shake 5 h
(4) Fe-Mn oxide bound (OX)
20 mL 1 M NH2OH·HCl in 25% v/v CH3COOH; shake 4 h
(5) Organic/sulfide-bound (OM/S)
2 mL 0.02 M HNO3 + 5 mL 30% H2O2, adjusted to pH 2 with concentrated HNO3; heat to 85 degrees C for 2 h with occasional agitation; add 3 mL H2O2; heat to 85 degrees C for 2 h with occasional agitation; cool and wash with 5 mL 3.2 M NH4OAc in 20% v/v HNO3; dilute to 20 mL; shake 30 min
(6) Residual (RES)
9.0 mL 16 M HNO3 + 3.0 mL 12 M HCl (concentrated); microwave digestion: 180 degrees C
aAfter Tessier et al., 1979 and modified by Keller and Vedy, 1994.
