[tonydoss]

Hi,

I use a sequential leaching procedure to leach soils. here a couple of the steps:
- 40mL 0.04M hydroxylamine hydrochloride in 25% (v/v) HOAc
- 10mL of 3.2M NH4OAc in 20% (v/v) HNO3

Here's the few doubts I have: when leaching in 40mL 0.04M hydroxylamine hydrochloride in 25% (v/v) HOAc, does that mean that 30 mL are 0.04M hydroxylamine hydrochloride and 10 mL are glacial HOAc? Or the concentration of HOAc is 25% but then what is it s volume added?

Similar question with NH4OAc: when using 10mL of 3.2M NH4OAc in 20% (v/v) HNO3, does that mean 20% of the 10mL are HNO3? If that’s the case, what is the concentration of HNO3 supposed to be? It seems to imply it is concentrated HNO3, however in this case I suspect the selectivity wouldn’t be that great since silicates would be attacked too. Or if “20% (v/v) HNO3” is the concentration of HNO3, what is then the volume of HNO3 added to 10mL of NH4OAc?

what do you think??
thanks in advance