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Date: | Thu, 25 Mar 1999 12:39:05 +-100 |
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Dear Mr Ravi Bhushan
As CHNOS cunsummable manufacturer and supplier. we have some experience in that field. The number of analysis you can run depend of the amount of O2 ecxess, the copper have to trap, and also depend on reduce copper quality you use. In sediment the amount of organic materiel, is very poor, comparing classical CHNOS organic standard. So the O2 amount necessary for combustion is very law. I suggest you to reduce the amount of oxygen you introduce for each analysis when you run sediment. So that the ecxess of O2 will be lower and the reduce copper consomption will be also lower and of course you will run more sample. Be carrefull if you run organique pure products you will have to increase O2 again.
The O2 quantity the copper can trap depend on the active surface it got. As producer of this product we worked hard in past to improve O2 absortion capacity and we know that it is not so easy to find the right recepies. All copper available on market are not similar. They look like similar but they are not! So using a good physical reduced copper can also increase the number of analysis you can run.
I will be interested to know how do you feel your tube?
Best regards
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: Ravi Bhushan [SMTP:[log in to unmask]]
Sent: Thursday, March 25, 1999 8:23 AM
To: [log in to unmask]
Subject: NC Analyser!
Dear Friends,
We have a FISONS NA1500 NC analyser. We are using it frequently for the
analyses of marine sediments for carbon and nitrogen content. Fisons
principals claim that one can run upto ~200 samples per column filling but
the best I have been able to run is not more than 120 samples averaging
~100 samples per filling, which is on a very lower side realising the
cost of each filling. Can anyone suggest some alternative. Also if anyone
can provide me the following information :
1) We are maintaining sample size of ~10mg, but it sometimes becomes
difficult for samples with very low carbon and nitrogen content. Does the
sample size controls the no of runs per filling.
2) Are there any standards available for analyses of marine sediments with
different concs. of carbon and nitrogen content.
3) Does the acidified samples (samples treated by HCl for removal of
carbonate fraction, HCl fumed filters etc) has any effect on the life of
the column filling. We have found while using acid treated samples that
column gets consumed very fast, sometimes just after 25-30 runs. Any
solution for this problem.
I shall be grateful if someone could give me feedback on this.
Thanking you in anticipation
Regards
Ravi
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* RAVI BHUSHAN ** Tel : (91)-(0)79-6462129 Ext:4047 *
* OCECS ** E-mail : [log in to unmask] *
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