Urea/Ammonia, UV method

Enzymatic method for the determination of urea and ammonia. Based on the spectrophotometric measurement of NADPH consumed through the reactions, after addition of urease (URE) and glutamate dehydrogenase (GlDH).

This rapid and simple specific enzymatic method is used for the simultaneous determination of urea and ammonia (ammoniumions) in foodstuffs such as wine, fruit juice, bakery products, dairy products, egg products, meat and seafood, as well as in paper, fertilizer, pharmaceuticals, cosmetics, water and biological samples.

Urea is the most important product of protein metabolism in mammals and the most abundant organic compound in their urine. Ammonia is mainly produced by microbial protein catabolism of organic materials. Therefore, these analytes may be used as reliable quality indicators for food products such as fruit juice, milk, cheese, meat and seafood. Urea and/or ammonia may also be sued as indicators of the presence of faeces, urine and microorganisms in water.

In the wine industry, ammonia determination is important in the calculation of yeast available nitrogen (YAN). This kit uses a glutamate dehydrogenase that is not inhibited by tannins found in grape juice and wine. However, YAN comprises three components: free ammonium ions, amino nitrogen from free amino acids and from the side chain of L-arginine. Thus, for the most accurate determination of YAN, all three components should be quantified, which is possible by using Nzytech’s L-Arginine/Urea/Ammonia kit.