I believe the tarnish on silver capsules in not an oxide but silver sulfide. 

Once upon a time I had some samples in the lab that had been sitting for a number of years and the silver was very tarnished. As a test, we removed the references and ran them along with some fresh ones in newly baked silver capsules. They were indistinguishable.  

With that said, I still like to bake silver capsules to ensure they are clean.


Yale Analytical and Stable Isotope Center
Yale Institute for Biospheric Studies
21 Sachem Street
New Haven, CT 06511
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> On Dec 4, 2018, at 1:39 PM, Scott Hughes <[log in to unmask]> wrote:
> Jordon,
> The oxidation on silver capsules can be removed by heating in air at 375oC for one hour prior to use.
> Sincerely,
> Scott Hughes
> EA Consumables, Inc.
> 5090 Central Hwy STE 3A
> Pennsauken, NJ 08109-4637
> Toll Free: 855-695-1312 x301
> Fax:         856-343-0550
> [log in to unmask] <mailto:[log in to unmask]>
> <>
> ----------------------- Original Message -----------------------
> From: "Munizzi, Jordon" <[log in to unmask]> <mailto:[log in to unmask]>
> To: [log in to unmask] <mailto:[log in to unmask]>
> Cc: 
> Date: Tue, 4 Dec 2018 18:33:21 +0000
> Subject: [ISOGEOCHEM] Oxidized silver capsules
> Hi everyone,
> In the wild days before it became a cost center, someone purchased many thousands of silver capsules for our TC/EA. Unfortunately, most have oxidized just in time for us to get our TC/EA up and running. Even some of the capsules that appear unoxidized are giving us blank issues.
> Has anyone tried to salvage oxidized silver capsules? I'm thinking of setting up something to stream hydrogen over a load of capsules while gently heating them, but perhaps there's another way? Preferably one that doesn't involve the phrase "just throw them out and buy more"?
> All input is much appreciated,
> Jordon
> ----------------------------
> Jordon Munizzi, PhD
> Research Facility Manager
> <Outlook-shjkp4qa.png>
> Department of Earth and Environmental Sciences
> University of Kentucky
> Ph: (859) 270-9177
> Fax: (859) 323-1938
> [log in to unmask]
> <>