[soil]Why soil fusion need potassium persulfate?

To destroy humic acids.
The humic acids are chelating agents and bind many metals.
Destruction of them releases bound metals

Bob M

[Only registered users see links. ] (chemistrynewbie!) wrote:

I am doing some experiments for determination of lead &zinc in the
soil. the mannual request the 0.1gsoil sample to be mixed with
0.5gpotassium persulfate.th e sample is then melted and fused~

would any of you could be kind enough to tell me the theory behind it
& the chemical equations involved.
Thank you very much

winnie

[Only registered users see links. ] (R Molony) wrote in message news:<[Only registered users see links. ].co.nz>...

how can the potassium persulfate can destry the humic acid??
can any chemicals eplace it???

Potassium persulfate oxidizes the humic acids, which are orgnic
compounds. I suppose other oxidizing agents like bleach would work, but
who'd want to handle that instead of the safer potassuim persulfate?

--OL

[Only registered users see links. ] (chemistrynewbie!) wrote in message news:<16a9e3b1.0402220531.70a0b16b@posting.google. com>...

When you fuse or melt the soil sample with persulfate, it converts the
organic matter (including humic acids) to its carbonate or carbon
dioxide. There are various fluxes for silicate containing materials
(soil) and the choice depends on the type of metal you want to
determine in it.
Potassium persulfate would be perhaps more suitable, safer to handle
than other fluxes.
If your object is to destroy organic matter in your soil sample, you
can use sodium peroxide , potassium chlorate, potassium nitrate or
sometime sodium carbonate with one of these is used. Consult your
instructor before using any of these substances.