Hello Michael,

The reason most users go with  the 0.1mm wires, at least for Cu is because once oxidized it becomes brittle. Any thinner Cu wire will
not hold for long.

Regarding the sharper peaks question, try using the continuous fused silicas capillary approach (Keith Goodman, "Hardware Modifications to an Isotope Ratio Mass Spectrometer Continuous-Flow Interface Yielding Improved Signal, Resolution, and Maintenance", Anal. Chem. 1998; 70(5), pp. 833-837).

I have used it and it works well, but you need to make sure not to disturb the furnace, as the fused silica will be suspended at 850C with no polyimide coating around it (very brittle!!)


Nabil Saad
Kinemed, Inc.

On Wed, Mar 26, 2008 at 1:47 PM, Kubo, Michael D. (ARC-SSX)[SETI INSTITUTE] <[log in to unmask]> wrote:

Has anyone had experience with building their own oxidation reactors with smaller ID tubing to improve their chromatography during the combustion process?  I know how much of a pain it is to change these reactors, and while a smaller ID/OD tubing will probably increase the chances of breakages during replacement (not to mention potentially decrease the life span of the reactor), for certain types of analyses the performance gain may make up for it.


Also, is there a reason most users go with the 0.1 mm wires instead of something a little thinner (say 0.05mm) to increase the packing efficiency (and thereby reduce dead volume) and also surface area?


I have to admit that this is the first time I've ever had to purchase reactors from Thermo (I inherited a stock from the previous technician) and I actually laughed at the customer service rep who gave me the price over the phone…


Thanks in advance,





Michael D. Kubo

NASA Ames Research Center

M/S 239-4

Bldg. N239, Room 327

Moffett Field, CA 94035


(650) 604-6110