A solution of polyhexamethylene biguanide hydrochloride (PHMB-HCl) was titrated with a standard solution of potassium poly(vinyl sulfate) (PVSK) using crystal violet (CV) as an photometric indicator cation. The end point was detected by a sharp absorbance change due to an abrupt decrease in the concentration of CV. A linear relationship between the concentration of PHMB-HCl and the end-point vo...

Theis and Steinhardt (1) recently have shown that, when native collagen is treated with calcium or magnesium chloride solutions, drastic shrinkage of the collagen occurs at low temperatures. It was further shown that potassium or sodium chloride has exactly the reverse effect; i.e., they actually increase the temperature at which collagen is said to contract. The effect of neutral salts upon th...

A new concept of critical point is expounded by analysing the potentiometric titration curves of aluminium salt solutions under the moderate slow rate of base injection. The critical point is defined as the characteristic spot of the Al salt solutions potentiometric titration curve, which is related to the experiment conditions. In addition, the changes of critical points reflect the influence ...

The author corroborates the data of Schmidt showing that the dissociation index of the third group of arginine is pK(3)' = 12.5. New titration data of edestin have been obtained in very alkaline solutions and show that there is a corresponding group with a titration index of pG' = 12.0, but present in much less quantity than can account for the arginine found on hydrolysis. The data support the...

Intracerebral inoculation of tuberde bacilli into normal guinea pigs induces acute meningoencephalitis with minor metastatic lesions. The disease is fatal in a relatively short time and is characterized by a rather typical succession of symptoms and a fairly characteristic temperature curve. The disease is produced by very small numbers of bacilli; and under standard conditions, survival time i...

Experimental methods and equations are given for calculating the concentration and dissociation constant of each acid or base in a mixture by use of its complex pH titration curve. The principle is illustrated by means of experimental data for malonic acid. This problem is important as an aid in determining the nature of the acids and bases in p~ant and animal fibers, fruits, culture media , pu...

Acid or base concentrations can be determined by performing an acid-base titration with coulometrically generated OHor H+ ions at a noble metal actuator electrode in close proximity to the pH-sensitive gate of an ISFET. It is shown, both theoretically and experimentally, that the relation between the acid or base concentration and the time needed to reach the equivalence point in the resulting ...

These three component inorganic ion-exchanger was synthesized under different condition. The most thermal and chemical properties of this material is prepared by intermixing solutions of sodium molybdate (0.1 M), sodium arsenate (0.1 M) and antimony(III) chloride (0.1 M) solution in different volume ratios at pH-1. The Ion-exchange capacity of all the samples was determined by column process. T...