Steps | Fractions | Reagents | Durations |
F1 | Exchangeable Fraction | 8 ml 1MMgC12 (pH7) | 1 hr. |
F2 | Carbonate Fraction | 8 ml 5MNaOAC12 (pH5) | 5 hrs. |
F3 | Fe-Mn Oxide Fraction | 0.04M NH20H.HCI | 6 hrs 96 + 20C |
F4 | Organic matter Fraction | 30% H202 (pH2) | 5 hrs 85 + 20C + 30 mins |
F5 | Residual | Aqua-regia HC104 | Until white fumes appeared |