Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: roztwór buforowy

Sortuj według:

Ogranicz wyniki do:

Potentiometric determination of the apparent dissociation constants and free energy of transfer of tris (hydroxymethyl) aminomethane buffer in various hydroorganic media

Anwar Z. M.

Bulletin of the Polish Academy of Sciences. Chemistry

2003

Vol. 51, No. 3-4

195-205

The apparent dissociation constant of tris (hydroxymethyl) aminomethane (Tris-buffer) was determined at (25.0 š 0.1)°C and / = 0.1 mol dm(-3) KNO3 by po-tentiometric pH titration in pure water and different hydroorganic solvent media. The organic solvents used were methanol, ethanol, N, N-dimethylformamide (DMF), acetone and dioxane. pKa(2) changes with an increase in the concentration of organic solvent. The results are discussed in terms of solvent characteristics. Solvent basicity and stabilization of the conjugate acid free base by hydrogen bonding interactions in hydroorganic solvent media relative to pure aqueous media as well as proton-solvent interaction play an important role in the dissociation equilibrium of the Tris buffer. The free energy of transfer of the protonated form of the Tris buffer to the neutral from water to mixtures of water + organic solvents are calculated.

Determination of lysozyme enthalpic pairwise interaction parameters using a titration calorimeter at 288.15, 298.15 and 308.15 K

Wszelaka-Rylik M.

Bulletin of the Polish Academy of Sciences. Chemistry

2003

Vol. 51, No. 2

135-141

The titration Omega MicroCal microcalorimeter (ITC) was used to obtain the enthalpy changes accompanying dilution of buffer solutions of lysozyme. Titration calorimetry affords a convenient method for the estimation of enthalpic pairwise solute-solute interaction parameters (hxx}- In this paper the results of determination of the enthalpy of dilution and then evaluated pair interaction coefficients (hxx) of lysozyme in a buffer containing 0.1 M sodium acetate, pH 4.25 at temperatures 288.15, 298.15, and 308.15 K are presented.

Roztwory buforowe w laboratorium

Danch M.

LAB Laboratoria, Aparatura, Badania

2002

R. 7, nr 5

22-24

W praktyce laboratoryjnej bardzo często zachodzi konieczność zapewnienia stałej wartości pH w badanym układzie. Środkami, które umożliwiają utrzymanie stabilnego pH są roztwory buforowe. W artykule omówiono podstawowe, klasyczne układy buforujące, a także trendy we współczesnej ,,chemii buforów".