Automated flow pH-method for the determination of total free fatty acids content in edible oils.

An automated flow pH-method for the determination of titratable acidity (TA) in edible oil without titration is proposed, based on pH measurements on an oil sample emulsion in a suitable reagent. The developed flow pH system involves two constant rate flows: the flow of oils samples and the flow of reagent: triethanolamine+KNO+HO+i-PrOH, in which oils is insoluble. The flows are mixed in the mixer forming the emulsion in which the free fatty acids (FFA) extraction is started.

Redox-potentiometric determination of peroxide value in edible oils without titration.

Standard methods for peroxide value determination in edible oils, which are based on KI oxidation by the hydroperoxides and volumetric titration of the liberated iodine, have been improved using redox-potentiometric iodine determination without titration. Stages of the KI oxidation and redox-potentiometric measurements were combined in the same electrochemical cell. The limit of quantitation of the new method is 0.

pH-Metric method for acid number determination in hydraulic oils without titration.

A heptane-mediated extraction of acids from hydraulic oils is proposed for pH-metric acid number determination without titration. The acids are extracted in the reagent consisting of triethanolamine and potassium nitrate dissolved in water and isopropanol. The use of heptane allows us to overcome the influence of additives in the hydraulic oil on the glass electrode.

pH-Metric determination of acid values in oilseeds without titration.

A new pH-metric method for determination of acid values in oilseeds without titration has been developed in the range 0.6-10 and more mg KOH/g. The method is based on a rapid (1-2 min) selective and complete extraction of free fatty acids from an oilseed test portion into a special reagent A, separation of the solution from the solid oilseed material by centrifugation or filtration, transfer of an aliquot of the solution into a pH-metric cell with reagent B for measurement of conditional pH(1)' of the formed mixture, addition of standard acid (HCl or H(2)SO(4)) and pH(2)' measurement.

pH-Metric determination of acid numbers in petroleum oils without titration.

A new pH-metric method without titration has been developed for determination of acid numbers lower than 0.1 mg (KOH) g(-1) (oil) in petroleum oils such as White, Transformer and Basic oils. The method is based on rapid and complete extraction of acids from an oil test portion into the novel reagent and measurement of the conditional pH in the ;oil-reagent' mixture by a glass electrode.