Nitrogen testing kits or probes

From: HANSON Steve [mailto:HANSON.Steve@deq.state.or.us]
Sent: Wednesday, June 22, 2005 6:56 PM
To: Volunteer water monitoring
Cc: Sandy Lyon
Subject: [volmonitor] Nitrogen testing kits and probes

I am requesting feedback from groups that have used nitrogen testing kits or probes. I'm interested in what kits/probes you have used, what the detection limits are (please specify mg/L as N or NO3), and how the kits performed for you. If you were able to compare the results from your kit/probe to samples analyzed at a laboratory, or any other quality control testing you did, I'd be very interested in how the samples compared .

I work with volunteer groups all over the state of Oregon who do water quality monitoring. I am trying to determine what methods could be used by Oregon groups to identify nutrient sources.

Thanks for your response.

Steve Hanson
Volunteer Monitoring Specialist
Oregon DEQ Laboratory
Phone: 503.229.5449
Toll Free: 1.800.452.4011
Fax: 503.229.6957
http://www.deq.state.or.us/lab/wqm/volunteermonitoring.htm
email: hanson.steve@deq.state.or.us
2020 SW Fourth Ave. Suite 400
Portland, OR 97201


Responses

-----Original Message-----
From: Linda Green [mailto:LGreen@uri.edu]
Sent: Wednesday, August 17, 2005 11:26 AM
To: HANSON Steve
Subject: RE: [volmonitor] Nitrogen testing kits and probes

I am program director of a volunteer monitoring program in RI, URI Watershed Watch, housed at Cooperative Extension. We have an analytical lab and use an Astoria-Pacific segmented continuous
flow nutrient autoanalyzer for our nutrient anlyses, since our waters are typically <2ppm in any form of nitrogen, which I think is pushing the limit on kits. I was fortunate that our Dean contributed ~ 75% of
the $42K it cost to purchase the autoanalyzer last year, it was replacing a 15 year old model that had been purchased by a professor I worked with. The prof departed without the analyzer, I took it over.

Best Wishes,

Linda Green
URI Cooperative Extension Water Quality
Department of Natural Resources Science
1 Greenhouse Road
Kingston, RI 02881-0804
401-874-2905
www.uri.edu/ce/wq/
www.usawaterquality.org/volunteer

Date: Wed, 22 Jun 2005 16:23:26 -0700
From: Lesley Jones <ljones@deschuteswatersheds.org>
Subject: Re: [volmonitor] Nitrogen testing kits and probes

Steve,
We only take grab samples and process in the lab. The methodology is:

TKN - EPA 351.2, sulfuric acid to pH<2 preservation, 4C, analyze within 48 hrs
Nitrate/Nitrite - EPA 300.0, 4C, analyze within 48 hrs
TP - EPA 365.3, sulfuric acid to pH<2 preservation, 4C, analyze within 28 days

The weird thing is that the Practical Quantitation Limit for TP is above the guideline of 0.05 mg/L. If there is a non-detect, the result is reported as one half of the PQL and is above the guideline. Therefore, no matter what result you get, the guideline is exceeded. The City of Bend lab is working on this issue to see if they can lower the PQL for TP.

Regarding nutrient probes, we have never used them, but I hear rumor that 'they are not as good as lab analyses methods'. I personally like to use meters and probes when possible, so I am interested to hear what you find out from this inquiry.

Have fun!

Lesley Jones, Water Quality Specialist
Upper Deschutes Watershed Council
Water Quality Monitoring Program
541-382-6850

Date: Thu, 23 Jun 2005 10:18:42 -0400 (EDT)
From: NOLNACSJ@aol.com

Steve, our nutrient samples are analyzed by the National Parks Service-Cape Cod National Seashore (CCNS) lab. In the past we used the County health department lab and the detection limits were not sensitive enough (especially for P) because they were primarily set up to do drinking water samples, not lake/pond ones. I have passed on your question to the lab chemist at the CCNS in hopes she will reply.

I am not aware of any field instruments that are inexpensive enough for volunteer groups to use, which also meet the detection limit requirements, or would be approved by some of the state agencies who require analyses be done under an approved QAPP and a certified lab. We do use YSI DO meters in the field for DO, but follow up with a water sample for Winkler analysis at a lab (for marine samples), if DO readings are below 5.0 mg/L.

I am interested in what you find out!

Judy Scanlon
Orleans Water Quality Task Force

Editor's note: Steve Hanson summarized the rest of the responses he received:

Responses are summarized in the following manner:

Nitrogen Testing Kits Comparison Information.
XContact/Organization
a. Kit Description
b. Method
c. Detectioin Limits/ Resolution
d. Performance
e. Comments