This article summarizes methods for determining proton surface charge at mineral/water interfaces. It covers conventional experimental procedures and discusses problems with the techniques. Also it involves recommendations for obtaining reasonable and comparable results. The term "comparable results" refers to comparison between results for the same solid as obtained in different laboratories. ...

The possibility of using disposable plastic-carbon potentiometric sensors as enzyme biosensors was examined. Urease enzyme was immobilized on poly(vinyl chloride) based Hor NH4-selective membranes using cellulose acetate. This approach has resulted in a potentiometric response on changing the pH of the solution or NH4 ion content due to an enzymatic reaction that occurs between urease and urea....

A potentiometric procedure for cysteine thiol group concentration monitoring in media generating free radicals was developed using a thiol specific silver-mercury electrode. Electrolytic deposition of mercury on a silver wire and treatment with 20 mM cysteine in 0.5 M NaOH were used to produce the electrode. A silver-chloride electrode in saturated KCl was the reference. A glass capillary with ...

The ionic composition of urine is a good indicator of patient's general condition and allows for diagnostics of certain medical problems such as e.g., urolithiasis. Due to environmental factors and malnutrition the number of registered urinary tract cases continuously increases. Most of the methods currently used for urine analysis are expensive, quite laborious and require skilled personnel. T...

Clomipramine hydrochloride, active component of an antidepressant drug, was determined in the pharmaceutical formulation by two kinds of potentiometric sensor; a PVC membrane sensor and a carbon paste electrode modified by MWCNTs and ionic liquid. Both sensors were corporated with clomipramine-tetraphenylborate ion-pair complex and they respond based on ion exchange mechanism. The best PVC memb...