The stability of uric acid in ammonium hydroxide.

1988 ◽  
Vol 34 (11) ◽  
pp. 2280-2282 ◽  
Author(s):  
P Ellerbe ◽  
A Cohen ◽  
M J Welch ◽  
E White
Keyword(s):  
Mass Spectrometry ◽  
Uric Acid ◽  
Initial Rate ◽  
Ammonium Hydroxide ◽  
Ammonium Hydroxide Solution ◽  
Hydroxide Solution ◽  
The Stability ◽  
Decomposition Curve

Abstract We examined the stability of uric acid in dilute aqueous ammonium hydroxide solution by mass spectrometry. Uric acid decomposes in ammonium hydroxide even as dilute as 15 mmol/L when the mole ratio of ammonium hydroxide to uric acid is 50:1. There are at least four products of the decomposition, two of which have been identified as allantoin and urea. The slope of the decomposition curve indicates that uric acid is destroyed at an initial rate of 2-3% per hour. In ammonium hydroxide at a concentration of 1 mmol/L and a mole ratio of ammonium hydroxide to uric acid of less than or equal to 3.4, uric acid is not detectably decomposed. Evidently, any method for determination of uric acid that involves treating the analyte with ammonium hydroxide before analysis may destroy it. Therefore, a published method described as being "definitive" for uric acid (J Clin Chem Clin Biochem 1985; 23:129-35) could produce incorrect results because it involves storing the uric acid in 15 mmol/L ammonium hydroxide at a mole ratio of ammonium hydroxide to uric acid of greater than 120:1.

scholarly journals Determination of the Stability of the Noncovalent Phospholipid Transfer Protein−Lipid Complex by Electrospray Time-of-Flight Mass Spectrometry

Biochemistry ◽  
2002 ◽  
Vol 41 (25) ◽  
pp. 8013-8018 ◽  
Author(s):  
A. P. M. de Brouwer ◽  
C. Versluis ◽  
J. Westerman ◽  
B. Roelofsen ◽  
A. J. R. Heck ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Time Of Flight ◽  
Phospholipid Transfer Protein ◽  
Lipid Complex ◽  
Transfer Protein ◽  
Flight Mass Spectrometry ◽  
Phospholipid Transfer ◽  
The Stability

Ammonia fumigation for reducing green mould wastage in oranges during ethylene degreening

1964 ◽  
Vol 4 (13) ◽  
pp. 173 ◽  
Author(s):  
D Leggo ◽  
JA Seberry
Keyword(s):  
Convenient Method ◽  
Laboratory Tests ◽  
Ammonium Hydroxide ◽  
Penicillium Digitatum ◽  
Ammonia Treatment ◽  
Ammonium Hydroxide Solution ◽  
Extensive Experiment ◽  
Hydroxide Solution ◽  
Excellent Control ◽  
Green Mould

The addition of ammonia to experimental cabinets reduced the development of green mould (Penicillium digitatum) wastage in oranges during ethylene degreening. The treatment consisted of introducing ammonia at a concentration of 6000 p.p.m. (v/v) three times every 24 hours throughout the three or four day degreening period. Ammonia gave excellent control of green mould wastage in wound inoculated oranges in preliminary laboratory tests. In an extensive experiment with Valencia oranges, surface inoculated with spores of P. digitatum, ammonia reduced green mould wastage when fruit was degreened at chamber loads of 25 and 50 per cent. These loads would represent the limits likely to be encountered commercially. The ammonia treatment did not cause rind damage to treated fruit. The evaporation of concentrated ammonium hydroxide solution is a practical and convenient method of adding ammonia to the degreening chamber.

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