What is direct ion-selective electrode?
Direct and indirect ion selective electrodes (ISEs) are two methods commonly used in biochemistry laboratories in order to measure the electrolytes such as sodium. In the direct ISE, the sample is not diluted and the results are correct even if the volume of plasma water is modified.
What is ion-selective electrode potentiometry?
An ion-selective electrode (ISE), is a type of electrochemical sensor that converts the activity of a specific ion dissolved in a solution into an electrical potential.
How does an ISE work?
The ion-selective electrode works based on the principle of a galvanic cell. The difference in potential between the electrode and the membrane depends on the activity of the specific ion in solution. The strength of the net charge measured is directly proportional to the concentration of the selected ion.
Which electrodes are used in potentiometry?
Reference electrodes generally used are hydrogen electrodes, calomel electrodes, and silver chloride electrodes. The indicator electrode forms an electrochemical half cell with the interested ions in the test solution. The reference electrode forms the other half cell.
What is direct potentiometry?
Direct potentiometry: utilized by blood gas machines and does not involve sample dilution. Indirect potentiometry: utilized by automated chemistry analyzers, such as the ones used at Cornell University, and involves sample dilution before analysis.
What is an ion-selective electrode explain its principle and working?
Principle of ion-selective electrode (I.S.E.) consists of a thin membrane across which only the intended ion can be transported. The transport of ions from a high conc. to a low one through a selective binding with some sites within the membrane creates a potential difference.
What is the principle of potentiometry?
Potentiometric Titration principle of Potentiometry Principle. When the pair of electrodes are placed in the sample solution or analyte, it shows the potential difference between two electrodes by the addition of the titrant or by the change in the concentration of ions.
What is the difference between direct and indirect ISE methods?
Direct ISE is the technique employed in blood gas and most other point-of-care analyzers whereas indirect ISE is used in the majority of biochemistry profiling analyzers sited in central laboratories.
What is an ion-selective electrode give examples?
Glass membranes are made from an ion-exchange type of glass (silicate or chalcogenide). This type of ISE has good selectivity, but only for several single-charged cations; mainly H+, Na+, and Ag+. A very common example of this type of electrode is the pH glass electrode.
What is ion-selective electrode used for?
Ion selective electrode (ISE) is an analytical technique used to determine the activity of ions in aqueous solution by measuring the electrical potential. ISE has many advantages compared to other techniques, including: It is relatively inexpensive and easy to operate. It has wide concentration measurement range.
What are the uses of ion-selective electrode?
Ion-selective electrodes (ISEs) are very similar in use to pH electrodes. They are used for chloride, potassium, calcium, carbon dioxide/carbonate, oxygen, and a variety of other ions. These methods are particularly suited for field analysis and online measurements.