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NEW Optical Kit for
Ammonium Concentration Determination
Accurate
determination of ammonium in aquatic environments is a critical measurement
when investigating Nitrogen cycling and nutrient dynamics. Historically,
methods for ammonium determination have been a source of frustration within
the scientific community due to the lack of a simple, accurate and affordable
method, particularly in the submicromolar range.
Recent developments in fluorometry have resulted
in the introduction of a new optical kit (10-303) specifically designed
for a new ammonium technique.
Ammonium Technique
The new ammonium technique offers researchers
and technicians an excellent alternative to existing colormetric methods.
Benefits of the fluorometric method include:
- Sensitivity: Detection in the submicromolar
range.
- Wide Range: Two protocols have been
developed to allow for use in a wide range of concentrations.
- Accuracy: More accurate than previous
methods for low ammonium concentration samples.
- Simple: Requires only one mixed reagent
and no special equipment other than a Turner Designs fluorometer.
- Convenient: Easy sample collection
and preservation.
- Affordable: Filter Fluorometer with
optical kit and one working reagent.
- Field Portable: Use with the 10-AU-005-CE
Field Fluorometer.
- One, Mixed Reagent: OPA, sodium sulfite,
and sodium borate.
The widely used colormetric indophenol blue
method is susceptible to inconsistent results, particularly with submicromolar
ammonium concentrations. The new fluorometric technique has been proven
to provide accurate and precise data over a wide range of water quality,
ammonium concentration and salinity.
This fluorometric method is particularly useful
for work in oligotrophic systems, where natural ammonium concentrations
are commonly in the submicromolar range.
Standard Concentration (µmol/L)
Recent Publications
Holmes, R.M., A.Aminot, R.Kérouel, B.A.Hooker,
B.J.Peterson. 1999 . A simple and precise method for measuring ammonium
in marine and freshwater ecosystems. Can. J. Fish. Aquat. Sci. 56:
1801-1808.
Kérouel, R., and A. Aminot. 1997. Fluorometric
determination of ammonia in sea and estuarine waters by direct segmented
flow analysis. Mar. Chem. 57:265-275.
The Ammonium Optical Kit (P/N 10-303) includes
two Near UV Mercury Vapor Lamps, 350nm excitation filter (310-390nm),
a 410-600nm emission filter, a 1:75 Attenuator plate, and a 10-300 Reference
Filter (>300nm). The 10-303 Optical Kit works in the 10-AU Digital
Field Fluorometer, TD-700 Laboratory Fluorometer and the Model 10 Analog
Fluorometer and also includes a reference filter (P/N 10-300).
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