A somewhat different approach was applied for the
analysis of polluted soils (technozems) in Palmerton,
Pennsylvania in the USA. The soil profile was studied
1 km to the southeast of a former plant that had been
smelting sphalerite (ZnS) for 80 years. The soil was
aerially contaminated with heavy metals, specifically,
zinc and lead, as well as by sulfuric acid [65].
The zinc forms were analyzed using the detailed
successive chemical extraction according to Zein and
Brummer and the synchrotron Xray technique. The
chemical extraction steps are the following: (1) 1M
NH4NO3 removes the exchangeable ions and water
soluble salts; (2) 1 M NH4OAc (pH 6) removes the
weakly complexed and carbonatebound metals; (3)
0.1 M NH3OHCl + 1 M NH4OAc (pH 6) removes the
metals bound to Mn oxides; (4) 0.25 M NH4EDTA
(pH 6) removes the metals bound to organic sub
stances; (5) 0.2 M NH4oxalate (pH 3.2) removes the
metals bound to weakly crystallized Fe oxides; (6)
0.1M scorbic acid + 0.2 M NH4oxalate (pH 3.2)
removes the metals bound to well crystallized Fe
oxides; (7) the residue includes the metals bound to
the remaining fraction [65]. This combination of ana
lytical methods is derived from the following ideas. As
the zinc forms are chemically extracted, the number of
phases decreases, which simplifies the spectroscopic
identification of the remaining phases. The successive
chemical extraction is the most efficient means for
identifying the most mobile and, hence, the most toxic
metal forms.