The measurement of sulfide, especially hydrogen sulfide, has held the attention of the analytical community due to its unique physiological and pathophysiological roles in biological systems. Electrochemical detection offers a rapid, highly sensitive, affordable, simple, and real-time technique to measure hydrogen sulfide concentration, which has been a well-documented and reliable method. This...

The experiments described above show that the rate of digestion and the conductivity of protein solutions are very closely parallel. If the isoelectric point of a protein is at a lower hydrogen ion concentration than that of another, the conductivity and also the rate of digestion of the first protein extends further to the alkaline side. The optimum hydrogen ion concentration for the rate of d...

1. The Donnan equilibrium furnishes a test for the ionic nature of any diffusible substance, since the ratio of the concentration of any ion on the two sides of a membrane must be equal to the ratio of the concentrations of any other ion of the same sign and valence, whereas a non-ionic substance would be equally distributed on both sides. 2. The distribution of trypsin inside and outside of ge...

This Module consists of three Web pages of required reading. The pagination is visible at the bottom of each page with direct links to adjacent pages. Introduction The driving force that causes metals to corrode is a natural consequence of their temporary existence in metallic form. To reach this metallic state from their occurrence in nature in the form of various chemical compounds (ores), it...

THE PULMONARY circulation has been the subject of many studies since the original measurement of pulmonary arterial pressure by Beutner in 1852.1 Of particular importance were the observations by von Euler and Liljestrand in 1946,2 that the administration of 10 per cent oxygen with 90-per cent nitrogen resulted in a significant rise in pulmonary arterial pressure in the cat. This observation wa...

S.P.L. Sgrensen not only introduced the p H concept, but in his classical paper from 1909 “Enzymstudien 11” he also described in great detail the colorimetric as well as the potentiometric methods for p H measurement, and he pointed out that two kinds of acidity must be distinguished: Actual acidity and titratable acidity. Previous to Sgrensen the acidity of a solution was usually determined by...

Introduction Perioperative use of Normal Saline is linked to hyperchloraemic or Strong Ion Difference (SID) related acidosis. It has been suggested, that this can be avoided by the use of balanced crystalloid solutions including Ringer’s Lactate (RL). Significant changes in SID were noted previously in cardiac surgery, however recent publication disproved the link between SID and hydrogen ion c...