A simple method for the titration of multicomponent acid-base mixtures

Abstract

A titration method has been developed to analyze acid mixtures, in which the pK values differed by 0.5 to 1 pH units. Instead of the use of equivalence points a buffer capacity curve is numerically derived from the titration curve resulting in a presentation similar to chromatograms and spectra. The consumption of the NaOH titrant is determined within pH intervals of 0.2-0.6 units around the pK values of the components. The buffer capacity measured is expressed as the consumption of NaOH over the pH interval. The amounts of compounds are found from these results using simple models of chemometrics. The method has been applied to a mixture of formic and acetic acids with concentrations of 0-3 mmol/20 ml with an error of 0-0.05 mmol. Furthermore a curve-fitting method based on a theoretical equation of buffer capacity can be applied with an error slightly larger than with the previous method. In this case, the pK values were also computed. For titrations beyond the pH range 4-10, the buffer capacity of water has to be subtracted from the titration results. The whole procedure requires including the computations about 3-6 min.

Pre-treatment methods of Edam cheese milk. Effect on cheese yield and quality

“…Cheese salt content was measured with potentiometric chloride titration (IDF 88/ISO 5943:2006). Titratable fatty acids (TFA) were measured by using the titration method of Moisio and Heikonen (1996). Moisture in the non-fat substance (MNFS) was calculated with a formula MNFS(g/kg) ¼ (100-TS)/(100-Fat) Â 1000.…”

Sensory evaluation, chemical composition and consumer acceptance of full fat and reduced fat cheeses in the Finnish market

“…The methods above are accredited according to EN ISO/IEC 17025. Free amino acids (FAA) were analysed by a titration method (Moisio & Heikonen, 1996).…”

Chemometric Method of PLS in the Treatment of Titrimetric Data when Opredeleniye of Arginine and Lysine in Mixed Solutions

“…Так. в работе [6] показано, что на основе хемометрического моделирования данных потен-циометрических кривых титрования возможно одновременное определение кислот, у которых значения рК отличаются на 0.5-1 единицы. Мето-дика апробирована на смесях муравьиная-уксус-ная кислота в диапазоне концентраций 0-3 ммоль с погрешностью, не превышающей 0.05 ммоль.…”