The premeabilities of planar lipid bilayer (egg phosphatidylcholine-decane) membranes to butyric and formic acids were measured by tracer and pH electrode techniques. The purposes of the study were (a) to establish criteria for the applicability of each method and (b) to resolve a discrepancy between previously published permeabilities determined using the different techniques. Tracer fluxes of...

The effect of pH and electrochemical potential on copper uptake, xanthate adsorption and the hydrophobicity of sphalerite were studied from flotation practice point of view using electrochemical and micro-flotation techniques. Voltammetric studies conducted using the combination of carbon matrix composite (CMC) electrode and surface conduction (SC) electrode show that the kinetics of activation...

A physic-mathematical model has been developed that is suitable for biosensors incorporating membranes and bisubstrate enzymes. The set of equations regarding the transport of reactants across the membrane, the bisubstrate enzymatic reaction, back diffusion of reactants and reaction products, are written down and simultaneously solved and transient response of the electrode is determined as...

a pvc ion-selective membrane electrode based on cd-tetraphenyl porphyrine as a carrier was prepared fordetermination of mno4- ion. this electrode revealed good selectivity toward permanganate ion over a widevariety of anions. effects of some experimental parameters such as nature of the plasticizer, the amounts ofcarrier and additive, and concentration of the internal solution on the potential ...

in order to preparing strontium ion selective electrode 6-(4- nitropheny1)-2-pheny14, 4- dipropy1-3, 5-diaza-bicyclo [3, 1, 0] hex-2-ene (npdbh) was used as an ionophore. this electrode responds to sr (ii)ion with a sensitivity of 28.2 ± 0.5 mv/decade over the range 1.0 x 10-6 to 1.0 mat ph 3.0-10.0. thelimit of detection was 2.4 x 10-7 m. the influences of membrane composition, the ph of the t...

By performing an acid-base titration by coulometric generation of OHor H+ ions at an inert electrode in close proximity to the pH-sensitive gate of an ISFET, it is possible to determine the acid or base concentration of a solution using the ISFET as an indicator device for the equivalence point in the titration curve. Typical values for the titration time are 0.1 to 10 s for acid or base concen...

The use of postural restriction in the treatment of patients with hiatus hernia has been analysed using continuous oesophageal pH measurements. It appears that it is not effective in the prevention of reflux of acid. The percentage of the time during which oesophageal pH remains below 5 is not significantly different when comparison is made during periods of sitting and lying. The frequency of ...

In this study, a dual microsensing electrochemical probe for measuring oxygen (O2) and pH levels was developed based on a dual recessed Pt disk electrode (each disk diameter, 10 μm) with the use of two Ag/AgCl reference electrodes (one for each disk of the dual electrode). One of the recessed Pt disks of the dual electrode was electrodeposited with a porous Pt layer and then coated with a hydro...

Here, a simple, quick, Low cost and sensitive Potentiometric method is described for tramadol hydrochloride measurement using .PVC membrane electrode based on neutral ligand (E)-N'-(1-(2-hydroxyphenyl)ethylidene)benzohydrazid. Besides, effect of various parameters like ionic additives, membrane solvent and pH on the Potentiometric response of the electrode are investigated. The best electrode p...