Technical Summary: Industrial Ammonia Analysis (Bulletin ref. TB079946A)
 

A simple and rapid enzymatic analysis for ammonia in a variety of biological fluids, e.g. in monitoring and control of culture media and fermentation processes in biotechnology industries.
 

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Ammonia (industrial)
GMRD-152
2 x 30 tests; 140 analyzer cycles
GM8 Series analyzers
 

Principle:

i) Ammonia is converted to L-glutamate by a-ketoglutarate in the presence of glutamate dehydrogenase (GLDH) and excess NADH in a brief pre-reaction:

ii) Under the conditions of the assay, the rate of oxidation of the excess NADH by peroxidase (POD) is inversely proportional to the total ammonia present:

Samples:
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Aqueous solutions (pH 5 - 7), culture fluid, etc.
25 µl
0.5 - 20.0 mmol/L (34 mg/dl) (0.34 g/L) by direct injection. Higher levels via pre-dilution
Typical within-run C.V. = 1 - 2 % @ 8.0 mmol/L (136 µg/ml)
0.2 mmol/L, ca 4 µg/ml
 

Reagent Stability:

Shelf life 9 months unopened when stored at 0 - 5°C. Reconstituted
NADH/a- ketoglutarate, 7 - 10 days (2 vials) if stored at 0 - 5°C.