Water Environment Federation (WEF) Discussion Forums
Home      Members   Calendar   Who's On
Welcome Guest ( Login | Register )
      

Home » WEF Discussion Forums » Laboratory Management & Technical Issues » TKN Digestion


TKN DigestionExpand / Collapse
Author
Message
Posted 5/6/2008 2:08:33 PM
Forum Newbie

Forum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum Newbie

Group: Forum Members
Last Login: 5/8/2008 7:36:46 PM
Posts: 1, Visits: 12
I am trying to find information on how to perform a digestion for TKN using an autoclave. Can anyone tell me if this is possible? Any information is greatly appreciated.

Thanks,
Andy



Saving the world was merely a hobby. My *vocation* has been that of inspector of desert water holes.-Abbey
Post #9067
Posted 5/13/2008 2:03:38 PM
Junior Member

Junior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior Member

Group: Forum Members
Last Login: 5/13/2008 5:33:19 PM
Posts: 10, Visits: 336
We are just embarking on the adventure of trying an autoclave method for total nitrogen.  We plan to follow the alkaline persulfate method that was evaluated by the USGS as an alternative to TKN.  We found it as Water-Resources Investigation Report 0.-4174.

We currently run TKN by block digestion and are enticed by better detection limits, higher sample through-put and the ablility to run TP concurrently.

We are hoping to make our first attempt in the next few weeks.

Hope this helps...

Post #9121
Posted 5/13/2008 2:04:40 PM
Junior Member

Junior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior Member

Group: Forum Members
Last Login: 5/13/2008 5:33:19 PM
Posts: 10, Visits: 336
Ooops!!!

That report number is 03-4174

Post #9122
Posted 5/13/2008 5:02:30 PM
Forum Member

Forum MemberForum MemberForum MemberForum MemberForum MemberForum MemberForum MemberForum Member

Group: Forum Members
Last Login: 6/26/2008 11:35:12 AM
Posts: 44, Visits: 286
This alkaline persulfate digestion is not the same as the one in standard Methods, 20th edition, according to the report. It would seem to be more applicable to the types of samples we analyze (our lab is currently also looking at combining TKN and TP analysis into one digestion). But it is not an approved method, so I don't see how we could use it.

Is there an EPA/SM approved alkaline persulfate method that will analyze both TN and TP together and can be run on acidified freshwater samples?

thanks,

aldri7@comcast.net

Post #9124
Posted 5/13/2008 5:31:05 PM
Forum Member

Forum MemberForum MemberForum MemberForum MemberForum MemberForum MemberForum MemberForum Member

Group: Forum Members
Last Login: 6/26/2008 11:35:12 AM
Posts: 44, Visits: 286
More to the point (as I read this further) - is there any alkaline persulfate digestion method (for both TP and TN) that is approved for NPDES compliance monitoring and safe drinking water act monitoring?

Ken

aldri7@comcast.net

Post #9125
Posted 5/13/2008 5:43:08 PM
Junior Member

Junior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior MemberJunior Member

Group: Forum Members
Last Login: 5/13/2008 5:33:19 PM
Posts: 10, Visits: 336
I'm sorry if I sent anyone on a wild goose chase.  I hadn't thought about other peoples need for EPA approved methods.  The samples we are planning to run are not permit required and thus they do not need to be run by an EPA approved method.  The samples are part of an additional project we are involved in and the persulfate method is approved for this particular project.

We run TKN/TKP by block digestion on our plant samples.

Lynn

Post #9127
Posted 5/14/2008 2:20:46 PM
Forum Member

Forum MemberForum MemberForum MemberForum MemberForum MemberForum MemberForum MemberForum Member

Group: Forum Members
Last Login: 6/26/2008 11:35:12 AM
Posts: 44, Visits: 286
No problem. We bandied the idea about for a day - until we went in and really read the method.

So no, our lab will not be able to do this....

Ken

aldri7@comcast.net

Post #9136
« Prev Topic | Next Topic »


Reading This TopicExpand / Collapse
Active Users: 1 (1 guest, 0 members, 0 anonymous members)
No members currently viewing this topic.

PermissionsExpand / Collapse

All times are GMT -5:00, Time now is 12:12am

Powered By InstantForum.NET v4.0.0 © 2008
Execution: 0.172. 10 queries. Compression Enabled.