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Date: | Tue, 11 Nov 1997 09:59:05 -0500 |
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>I don't know the amount of hydrochloric acid you used, but I
>suppose that high pH waters would need more than some drops.
>The most concentrated HCl contains cca. 64 % H2O, so this
>method would bring industrial water into the sample. Is there a
>reason why 100% H3PO4 is not used for this purpose?
A good point! We (Martin Knyf in H. Schwarcz's lab) normally use H2SO4.
This can be obtained as 100%, but care must be taken as it is highly
hygroscopic.
I think that I would avoid 100% H3PO4, because it isn't. If you see what I
mean. Concentrated phosphoric acid contains a significant proportion of
polyphosphoric acids, such as H4P2O7. These will hyrolyse at lower
concentrations and take up oxygen, probably with an isotopic offset. It is
a trivial effect, but is probably better avoided.
Hilary
.
Hilary Stuart-Williams Ph.D. - Climate and behaviour study using stable
isotopes.
School of Geography and Geology, McMaster University, Hamilton
Ontario, Canada L8S 4M1
Telephone: (905) 525-9140 Ext. 27594 (Bus.) (905) 523-8935 (Home)
Fax (905) 522-3141, Email [log in to unmask]
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