Results 211 to 220 of about 803,542 (263)

Stability of Diltiazem in Acid Solution

Journal of Pharmaceutical Sciences, 1991
A brief study of the stability of diltiazem was conducted at 70 degrees C in the pH range of 0.45 to 6.1 using polarimetry. Racemization did not occur. The hydrolysis rate of the acetate ester moiety was found to be slow, with a minimum in the pH-rate catenary at approximately pH 3.5.
L, Chafetz, K P, Shah
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Acidity of Frozen Electrolyte Solutions

The Journal of Physical Chemistry B, 2006
Ice is selectively intolerant to impurities. A preponderance of implanted anions or cations generates electrical imbalances in ice grown from electrolyte solutions. Since the excess charges are ultimately neutralized via interfacial (H(+)/HO(-)) transport, the acidity of the unfrozen portion can change significantly and permanently. This insufficiently
Robinson, Carmen, Boxe, C. S., Guzmán, M. I., Colussi, A. J., Hoffmann, M. R.   +4 more
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Analysis of peracetic acid solutions

Talanta, 1966
In the estimation of peracetic acid in aqueous solution, hydrolysis of the peroxy group must be taken into account. The best volumetric method is an indirect one using cerium(IV) as the oxidant, followed by iodometric titration of the excess of cerium(IV). A spectrophotometric estimation of the hydrogen peroxide present, based on the peroxytitanium(IV)
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[A-] in weak acid solution

Journal of Chemical Education, 1986
The cubic equations that arise when accurately calculating the concentrations of the various species of a monobasic acid or base in solution have recently attracted some attention in this journal.
Ian J. McNaught, Gavin D. Peckham
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Kinetics of hydrolysis of peroxybenzoic acid in aqueous acidic solution

Journal of the Chemical Society B: Physical Organic, 1971
The kinetics of decomposition of peroxybenzoic acid have been studied in acidic solutions in a wide range of concentrations of the reactants at various temperatures and at ionic strength 0·2M. The rate equation is (i) where k1=(2·8 ± 0·1)× 10–7 s–1 and k2=(5·14 ± 0·07)× 10–6 l mol–1 s–1 at 25°C.
SECCO, FERNANDO, S. CELSI
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Solute clusters in aqueous citric acid solutions

Chemical Engineering Science, 1991
Abstract Densities of aqueous citric acid monohydrate solutions are examined at three different concentrations. Two supersaturated solutions exhibit density gradients in a vertical column, but a saturated solution does not. The density gradients can be expressed satisfactorily by use of a theoretical model based on the Brownian diffusion equation for
Kazunari Ohgaki, Yoshihiro Makihara, Makoto Morishita, Masahiro Ueda, Norio Hirokawa   +4 more
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Depolymerization reactions of hyaluronic acid in solution

International Journal of Biological Macromolecules, 1994
Samples of microbial sodium hyaluronate were degraded by heating, ultrasonication ultraviolet (UV) and gamma-ray irradiation and enzymatic treatment. The weight-average molecular weight, Mw, of hyaluronate in 0.15 M NaCl and 0.06 M Na2HPO4 was determined by gel filtration with UV detection. The Mw of the degraded samples varied from 8 x 10(4) to 1.38 x
M, Reháková, D, Bakos, M, Soldán, K, Vizárová   +3 more
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Acid solution

Nature Catalysis, 2022
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Solutions in difluorophosphoric acid

2011
The physical and inorganic chemistry of solutions in difluorophosphoric acid, HPO₂F₂, has been studied, as part of a general study of solutions in non-aqueous protonic solvents. Difluorophosphoric acid is a colourless, associated liquid which might be expected to have solvent properties similar to those of other protonic systems such as H₂O, H₂SO₄ and ...
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RACEMIC ACID IN SOLUTION

Journal of the American Chemical Society, 1922
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