Used solution

Soil (g)/Solution Volume (ml)

Temperature (˚C)

Time (h)

Chemical forms

Row

MgCl₂ (1 mol/l), pH = 7

16

25

1

Water Soluble and Exchangeable WsEx.

1

NaOAc (1 mol/l), pH = 5

16

25

5

Carbonate Car.

2

NH₂OH×HCl (0.04 mol/l) in HOAc (%25 v:v), pH = 2

16

96

6

Iron and Manganese Oxides Fe-MnOx.

3

3 ml HNO₃ (0.02 mol/l), 8 ml H₂O₂ (%30), pH = 2, 5 ml NH₄OAc (3.2 mol/l)/HNO₃ (%20 v in v)

16

85

5.5

Organic Om.

4

(3:1 v/v) HCl:HNO₃

16

130

2

Residual Res.

5