Evaluation of Ferrous Thiocyanate Colorimetric Method

Abstract

The colorimetric ferrous thiocyanate method, first proposed by Young, Vogt, and Nieuwland, has been tested on a variety of autoxidized materials. It was found fundamentally accurate on hydrocarbon materials containing no conjugated diolefins; on diolefins the results varied considerably with time and were therefore of only empirical value. The precision was relatively poor (approximately ± 5 to 10% Of the absolute value) but the method was sensitive to very small peroxide concentrations.Presence of FERROUS ion has been used extensively as a reducing agent for the determination of organic peroxides. * One of the common methods involving ferrous ion, originally proposed by Young, Vogt, and Nieuwland ( 7), comprises reduction of the sample in an acidified solution of ferrous thiocyanate in methanol followed by measurement of the depth of color of the ferric thiocyanate produced. Bolland, Sundralingam, Sutton, and Tristram (3) used this method with slight variations in rubber research, and Farmer et al. ( 3) based theoretical conclusions on results using this method. Lips, Chapman, and McFarlane (5) used a similar method with acetone as solvent in place of methanol.

Stimulation of human platelet guanylate cyclase by unsaturated fatty acid peroxides.

“…On the other hand, methanol (final concentration of 50%) was added to the remaining fatty acid emulsion treated with lipoxidase. This methanol solution was utilized for determination of the peroxide value (peroxide content of emulsions) by the ferrous thiocyanate method as described by Wagner et al (31). Reagent (3 ml) was added to the sample (20 ml) and the absorption of 500 nm was measured and compared with standard ferric chloride that had been similarly treated.…”

“…Emulsions containing 1 mM arachidonic acid were oxidized by the various amounts of lipoxidase at 300 for 10 min. The extent of the oxidation was measured by de-termining the peroxide value by the ferrous thiocyanate method (31). Emulsions of arachidonic acid of different peroxide values were tested on guanylate cyclase.…”

“…Arachidonic or linoleic acid peroxide was prepared by incubation of either fatty acid at 0.1 mM with soybean lipoxidase at 15 ,g/ml for 10 min at 300 and added directly to the reaction mixture of the guanylate cyclase. The peroxide values in fatty acid emulsions were determined by the ferrous thiocyanate method (31). gated (Table 4).…”

Increased Production of Antioxidative Sesaminol Glucosides from Sesame Oil Cake through Fermentation byBacillus circulansStrain YUS-2

“…Anti-lipid peroxidation and free radical scavenging activities of compounds in the fermented SOC were evaluated by degrees of inhibition of oxidation of linoleic acid 5) and by the decrease of DPPH, 6) respectively. Anti-lipid peroxidation activity was deˆned as the inhibition ratio of oxidation in which the perfect anti-lipid peroxidation was indicated as 1.0.…”

Autoxidation of Chloroprene

“…This reagent reacts very slowly with dialkyl per oxides and therefore gives an upper limit to the hydroperoxide content of a peroxide sample. A much more sensitive reagent was ferrous thiocyanate in methanol (19), which again generally estimates hydroperox ides and not dialkyl peroxides.…”