Dear Dr Johnston.

We are manufacturer and distributor of cunsummable for CHN,O,S analysis. We Got lot of customer in IR analysis field.

We will be present at Pittcon 99 in Orlando booth 1383. We will be please to meeting with you about your problem if you attend this show. We are going to try to help you now. 

If you want to analyse your sample without evaporating the solvant I suggest you to use our smooth tin capsules 1.06 x 5.5 mm (ref 84.9900.26) particularly dedicated for volatil component analysis.

If you can wait for solvant évaporation, I suggest you to use a large capsule for solid as exemple 5.0 x 9.0 mm (Ref 76.9811.26). Put your liquid sample inside and wait for aceton evaporation. In that case, you have to check the maximum sample size you can take to avoid sample creeping.

Of course if you use smooth capsules you will have the problem of higher tin amount. So you need to increase oxygen injection level for capsules tin oxidation.

If you want to improve combustion of sample difficult to burn, I suggest you to add vanadium pentoxide (ref 99.0709.10) in powder to your solid sample in tin capsules. So that you increase the combustion temperature and you bring more oxigen to your sample.

You can see all products we supply at http://perso.wanadoo.fr/courtage.analyses.services 


Best regards/ Sincères salutations
Laurent Bertal
Manager

e.mail: [log in to unmask]
http://perso.wanadoo.fr/courtage.analyses.services
Tel: + 33 2 35 07 60 00
fax: + 33 2 35 70 64 39

 

-----Original Message-----
From:   Andrew Johnston [SMTP:[log in to unmask]]
Sent:   Thursday, February 25, 1999 3:17 PM
To:     [log in to unmask]
Subject:        Tin cups for elemental combustion: tips + advice

Hi

I am using some solvents to transfer an azo dye into tin cups for
elemental combustion and then ms analysis. This has proved to be
tricky as the solvent, acetone, has the effect of creeping up the
sides and over the top of the cup resulting in loss of sample.

To reduce this I have been using Chromosorb and it works to some
extent but nothing is ever perfect....

so I thought I would use the smooth wall tin cups with a flat base.

They work great and dont need any chromosorb!!

Now this is a whole bunch more tin being combusted

Does anyone have any advice or tips to improve the combustion of the
sample. I remember someone telling me that it is best to increase the
O2 time.

We are using an ANCA SL sampler converter attached to a 20-20 IRMS
Europa Scientific.

Any advice or tips are most welcome.

Andrew Johnston


Dr A.M.Johnston
CEP
SCRI
Dundee
DD2 5DA
Scotland

Tel No: 44 1382 562731
Fax No: 44 1382 562426