Separation of Hydrogen Peroxide from Organic Hydroperoxides

Abstract

drops of concentrated sulfuric acid and 10 ml. of hydrofluoric acid (48%). This is heated until dry, ignited, cooled, and weighed. The difference in weight represents silica.Any residue left in the platinum crucible is fused with potassium acid sulfate, the mass dissolved in hydrochloric or sulfuric acid (1 to 9), and the contents are added to the combined original filtrates which should have a total acidity of 10 to 20% and a total volume of not more than 250 ml. The required amount of halomandelic acid is now added and the zirconium content of the sample determined as described above.Results obtained by this procedure are given in Table III. SUMMARY Zirconium in aluminum alloys can rapidly and conveniently be 'determined gravimetricaliy by the mandelate method. The use of p-chloroor p-bromomandelic acid is preferred to mandelic acid (4). No significant difference exists between the chloro and bromo derivative. These reagents are now available com-mercially from the H.

The relationship between CO2 assimilation, photosynthetic electron transport and water–water cycle in chill‐exposed cucumber leaves under low light and subsequent recovery

“…The content of H 2 O 2 was measured by monitoring the A 410 of titanium-peroxide complex following the method described by MacNevin & Uron (1953) and Patterson, Mackae & Mackae (1984). For the measurement of lipid peroxidation in leaves, the thiobarbituric acid (TBA) test, which determines malonaldehyde (MDA) as an end-product of lipid peroxidation, was used.…”

Oxidative metabolism in tomato plants subjected to heat stress

“…The methods used for extraction of H 2 O 2 were those of McNervin and Uron (1953) and Brennan and Frenkel (1977). Hydroperoxides form a specific complex with titanium (Ti +4 ), which can be measured by colorimetry at 415 nm.…”

Involvement of Hydrogen Peroxide in the Regulation of Senescence in Pear

“…Hydroperoxides form a specific complex with titanium (Ti4+) which can be measured by colorimetry (19). Peroxides were extracted by homogenizing 100 g fruit tissue in 200 ml cold acetone.…”

“…The homogenate was filtered and the filtrate brought to 300 ml with water. Two ml of a titanium reagent (20% titanic tetrachloride in concentrated HCl, v/v) were added to 20-ml samples of the peroxide extract, followed by the addition of 4 ml concentrated NH40H to precipitate the peroxide-titanium complex (19). After centrifugation (5 min at 10,000g), the supernatant was washed repeatedly with acetone, and brought to a final volume of 20 ml with water.…”