THE COLORIMETRIC DETERMINATION OF CARBOHYDRATES IN PLANTS BY THE PICRIC ACID REDUCTION METHOD II. THE DETERMINATION OF STARCH AND OTHER “RESERVE” POLYSACCHARIDES1

1924 ◽  
Vol 46 (7) ◽  
pp. 1670-1675 ◽  
Author(s):  
Walter Thomas
Keyword(s):  
Reduction Method ◽  
Picric Acid ◽  
Colorimetric Determination ◽  
Acid Reduction

Colorimetric Determination of Cyanide Liberated from Apricot Kernels

1977 ◽  
Vol 60 (4) ◽  
pp. 954-956 ◽  
Author(s):  
Keith L Egli
Keyword(s):  
Hydrogen Cyanide ◽  
Steam Distillation ◽  
Sodium Hydroxide Solution ◽  
Picric Acid ◽  
Colorimetric Method ◽  
Potassium Cyanide ◽  
Colorimetric Determination ◽  
Apricot Kernels ◽  
Aoac Method

Abstract A simple colorimetric method is described for determining the quantity of hydrogen cyanide produced by the spontaneous decomposition of amygdalin in apricot kernels. The evolved cyanide is collected in sodium hydroxide solution and assayed colorimetrically by reaction with picric acid. Results for duplicate assays, 3.02 and 3.06 mg CN-/g, compare well with those obtained by AOAC method 26.115 which specifies steam distillation and silver nitrate titration; results for triplicate assays were 3.02, 3.03, and 3.08 mg CN-/g by the latter. Recovery of cyanide from potassium cyanide at a level equivalent to 243 μg CN-/g was 101.0%.

Simplified Automated Method for Determination of Urinary or Serum Uric Acid, Based on Reduction of Ferric-Phenanthroline Complex

1975 ◽  
Vol 21 (1) ◽  
pp. 125-129 ◽  
Author(s):  
John W Nelson ◽  
K K Batra
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Reduction Method ◽  
Phosphotungstic Acid ◽  
Colorimetric Method ◽  
Automated Method ◽  
Phenanthroline Complex ◽  
Acidic Conditions ◽  
Acid Reduction

Abstract We describe an automated colorimetric method for determination of uric acid in serum or urine by use of an AutoAnalyzer II or SMA 12/60 (Technicon Corp.). The method depends on reduction of a ferric-phenanthroline complex by uric acid under acidic conditions to a ferrous-phenanthroline complex, which absorbs at 505 nm. Advantages of this method over other methods now in use are that color and concentration are linearly related (to 20 mg/100 ml); aqueous reagents are easily prepared, stable, and inexpensive; and interference from ascorbic acid has been eliminated by use of an alkaline copper-containing diluent. The analysis is also free of interference from glucose, creatinine, glutathione, salicylates and hemoglobin. Correlation with results of the Technicon phosphotungstic acid reduction method is excellent (r = .996). Correlation with results of an automated uricase method is satisfactory (r = .979). Recovery of uric acid was 101% over a wide concentration range.

Amines in Fish Muscle: I. Colorimetric Determination of Trimethylamine as the Picrate Salt

1945 ◽  
Vol 6d (5) ◽  
pp. 351-358 ◽  
Author(s):  
W. J. Dyer
Keyword(s):  
Picric Acid ◽  
Colorimetric Method ◽  
Fish Muscle ◽  
Colorimetric Determination ◽  
Acid Reagent ◽  
Fishery Products

A sensitive accurate colorimetric method for trimethylamine determination is presented, based on the extraction with toluene of an alkaline sample containing 0.002 to 0.02 mg. trimethylamine nitrogen, and the formation of the yellow coloured picrate by mixing with a picric acid reagent. The application of the method in fishery products and effects of interfering substances have been investigated.

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