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HI All--

If it's the GCC tubes, practice packing the reduction (copper only) first....

take care

gerry

Quoting Bill Holmes <[log in to unmask]>:

> Mike,
> Are you talking about Thermo part number 1040920 used in the GC-C/III
> combustion furnace? This is about the smallest ID tube you can get wires
> through. There's not much room to eliminate dead space and improve
> chromatography. Perhaps you could use a greater number of smaller wires. For
> our non-Thermo GC-C-IRMS, we use a wider bore tube and put in more wires (2
> each Cu, Ni, Pt). This results in the same chromatography, but much greater
> oxidative capacity - no need to re-oxidize frequently.
>
> If your looking to reduce dead volume, start by replacing the Valco union on
> the GC side of the ox reactor. Use a narrow bore union (Valco part #ZRU1.5L)
> and be sure to burn off 5mm of the polyimid coating from the end of the
> capillary before inserting into reactor.  I'll send you the pdf diagram off
> list.
> -Bill
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Bill Holmes
> UC-Davis Stable Isotope Facility
> 2220 Plant & Env Sci
> One Shields Ave
> Davis, CA 95616
> Phone: (530) 752-8100
> FAX: (530) 752-4361
> stableisotopefacility.ucdavis.edu
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
>  _____
>
> From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
> Of Kubo, Michael D. (ARC-SSX)[SETI INSTITUTE]
> Sent: Wednesday, March 26, 2008 1:47 PM
> To: [log in to unmask]
> Subject: [ISOGEOCHEM] DIY Oxidation Reactor -- Better Chromatography with
> Smaller Tubes?
>
>
>
> 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,
>
> Mike
>
>
>
>
>
> ****************************************************************************
> ************************************************************
>
> Michael D. Kubo
>
> NASA Ames Research Center
>
> M/S 239-4
>
> Bldg. N239, Room 327
>
> Moffett Field, CA 94035
>
>
>
> (650) 604-6110
>
>
>
>