AOCS Standard Norms and Compatible Instruments for UV/Vis Spectroscopy

This ISO method specifies a colorimetric method for the determination of the phosphorus content of animal and vegetable oils and fats.

This method determines phosphorus or the equivalent phosphatide content by ashing the sample in the presence of zinc oxide, followed by the spectrophotometric measurement of phosphorus as a blue phosphomolybdic acid complex.

Total gossypol defines gossypol and gossypol derivatives, both free and bound, in cottonseed products that are capable of reacting with 3-amino-1-propanol in dimethylformamide solution to form a diamino-­propanol complex, which then reacts with aniline to form dianilinogossypol under the conditions of the test method.

This method determines the color of the test sample after treatment with a specified bleaching earth under the conditions of this test.

This method determines the color of the test sample after treatment with a specified bleaching earth under the conditions of this test.

This method is designed to examine the color of oil and fat spectrophotometrically.

This method is used to determine mg/kg (ppm) of chlorophyll-related pigments (predominantly pheophytin a) in oils from spectrophotometric absorption measurements at 630, 670, and 710 nm.

This method determines total chlorophyll pigments, expressed as pheophytin a, in crude vegetable oils. The method is suitable for the determination of quantities of chlorophyll pigments higher than 1 mg/kg (1 ppm).

This method is used to determine mg/kg (ppm) of chlorophyll in cold-pressed oil (e.g., virgin olive oil) and chlorophyll-related pigments (predominantly pheophytin a) in crude heated oils from spectrophotometric absorption measurements at 630, 670, and 710 nm.

This spectrophotometric method determines polyunsaturated acids in animal and vegetable fats, focusing on natural cis isomers, small amounts of preformed conjugated material, and pigments with significant absorption changes. The conjugated constituents are determined by measuring the ultraviolet absorption in a purified solvent.

This method determines the amount of aldehydes (principally 2–alkenals and 2,4–dienals) in animal and vegetable fats and oils, by reaction in an acetic acid solution of the aldehydic compounds in an oil and the p-anisidine, and then measuring the absorbance at 350 nm.

This method permits the direct determination of the 2-thiobarbituric acid value (TBA value) in oils and fats without preliminary isolation of secondary oxidation products. This standard is applicable to animal and vegetable fats and oils, fatty acids and their esters, partial glycol esters, and similar materials.

This method is used to determine mg/kg of chlorophyll-related pigments (predominantly pheophytin a) in oils from spectrophotometric absorption measurements at 630, 670, and 710 nm.

This method measures the color of commercial fatty acids and expresses the color as percent transmission at 440 and 550 nm (percent transmittance at 440/550 nm). Alternately, the method can be used to designate a photometric index to characterize the color which is expressed as 100 with the absorbance at each of the two wavelengths, 440 and 550 nm.

This method determines the color of products that are completely liquid and clear by comparison with artificial standards.

This method determines the diene conjugation of unsaturated linkages present, expressing this value as a percentage of conjugated dienoic acid.