Dear Simon,

We recently use  a mixture of V2O5 and NaPO3 in Cu capsules.
The reaction is COMPLETE  at  800C within 7minutes. This time
refers to 8mg BaSO4 (for dual inlet MS). I do not know if it would be
as good with Sn capsules into which some Cu is loaded with sample
and reagent.


At 08:44 1.02.01 -0800, you wrote:
>Hello everyone,
>
>As there's a small S conversation going on, I thought I'd ask if anyone
>might have any suggestions as to how to analyse d34S of BaSO4 by elemental
>analysis?  I find that I often get very variable yields of SO2, which I
>think is due to inconsistent heating of BaSO4 during Sn combustion, and
>hence incomplete decomposition of BaSO4.  I've tried a couple of things to
>try and increase the temperature/duration of the Sn combustion (e.g. using
>a larger Sn cup, using two Sn cups, adding PbO or sucrose, etc.), and this
>helps, but doesn't completely solve the problem.  I'm currently using a
>single quartz tube at 1000 C - has anyone tried using a double tube
>configuration with an alumina tube at higher temperature (1300+ C) for the
>combustion, and then a quartz tube with Cu at 1000 C?  Alternatively, has
>anyone identified an effective additive to promote complete BaSO4
>decomposition?
>
>Thanks in advance for any help or suggestions.
>
>Cheers,
>Simon
>
>*****
>Simon R. Poulson
>Dept. of Geological Sciences, MS-172
>University of Nevada-Reno
>Reno, NV 89557-0138
>USA
>Phone: (775) 784-1104
>Fax: (775) 784-1833
>[log in to unmask]
>*****