Extractants

Ratio(w/v)/Time/Temperature

Pool

Reference

1 M NH4Cl

1:6/16h/room temperature

Neutral salt soluble/exchange

[12]

0.005 M DTPA

1:2/2h/room temperature

Chelating, extractable

[13]

1 M HCl

1:33.3/2h/room temperature

Weak acid extractable

[14]