How does fluoride ion-selective electrode work?
How does fluoride ion-selective electrode work?
The ion-selective electrode (ISE) typically consists of an inner reference electrode plus a membrane that provides the interface between the sample solution and the ISE. A potential develops across the membrane that depends on the difference in the activity of a specific ion on each side of the membrane.
What are ion-selective electrodes give examples?
Glass membranes Chalcogenide glass also has selectivity for double-charged metal ions, such as Pb2+, and Cd2+. The glass membrane has excellent chemical durability and can work in very aggressive media. A very common example of this type of electrode is the pH glass electrode.
What is ISE and its principle?
PRINCIPLE: An Ion-Selective Electrode (ISE) makes use of the unique properties of certain membrane materials to develop an electrical potential (electromotive force, EMF) for the measurements of ions in solution.
What are some advantages of ISE?
ISE has many advantages compared to other techniques, including:
- It is relatively inexpensive and easy to operate.
- It has wide concentration measurement range.
- As it measure the activity, instead of concentration, it is particularly useful in biological/medical application.
What is the purpose of TISAB?
A total-ionic strength adjustment buffer (TISAB) is used to adjust samples and standards to the same ionic strength and pH; this allows the concentration, rather than the activity, to be measured directly and often read directly off a meter.
What is the most common ion-selective electrode?
With respect to process analytical applications of ion-selective electrodes, the oldest and most common is the glass pH electrode.
Which of the following is used as reference electrode during analysis of fluoride by using ion-selective electrode?
Some commercially available reference electrodes have an internal junction which minimizes the liquid junction potential between the sample solution and the electrolyte in the reference electrode (KCl).
What is ISE electrolyte?
As previously mentioned, indirect ISE measures the mean concentration of electrolytes in plasma, i.e. the weighted average between the concentration of the electrolyte-containing water and the electrolyte-free protein/lipid.
What are the applications of ion-selective electrode?
FIELDS OF THE APPLICATION OF ISE the electrode are used in following fields and branches: food industry, agriculture, agronomy, medicine, chemistry, physics, biology, stomatology, enviroment protection, etc.
What is ISE measurement?
Ion concentration measurement or ion-specific (ISE) measurements can be performed in every laboratory for a variety of sample types including water, food and beverage, pharmaceuticals, and biological samples. To evaluate a sample’s ion-specific performance, the best resource is slope S, also known from pH measurement.
What is ISE testing?
Ion selective electrode (ISE) is an analytical technique used to determine the activity of ions in aqueous solution by measuring the electrical potential.
What is the mechanism of action of fluoride?
In the 1980s, it was established that fluoride controls caries mainly through its topical effect. Fluoride present in low, sustained concentrations (sub-ppm range) in the oral fluids during an acidic challenge is able to absorb to the surface of the apatite crystals, inhibiting demineralization.
Why is fluoride prescribed?
Fluoride is used to prevent tooth decay. It is taken up by teeth and helps to strengthen teeth, resist acid, and block the cavity-forming action of bacteria. Fluoride usually is prescribed for children and adults whose homes have water that is not fluoridated (already has fluoride added).
What is fluoride analysis?
Fluoride analyses using the ion selective electrode are simple, sensitive, and rapid. Recoveries are usually >90%, but this is dependent on the type of sample and the sample preparation required. Sample for ISE analysis must be prepared to solubilize the fluoride in the sample.
What is the masking agent in TISAB?
Often, 0.03% w/v sodium citrate has been used as the masking agent in TISAB solutions [26, 27, 29, 39, 40, 44]; however, much higher concentrations, has also been used [23, 40, 43]. The most commonly used CDTA concentration is 0.4% w/v [40, 42].
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.
What is the role of TISAB in fluoride analysis?
TISAB adjusts ionic strength, buffers pH to 5-5.5, and contains a chelating agent to break up metal-fluoride complexes. Calibration is performed by analyzing a series of standards and plotting mV vs. fluoride concentration on semilog paper or by calibrating the ion meter directly in terms of fluoride concentration.
What is direct ISE and indirect ISE?
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 ISE in clinical chemistry?
ISE means ion-selective electrodes. Indirect ISE: Measures on a total plasma sample (or serum) that has been diluted with a large volume of diluent. Requires that the plasma and erythrocytes are separated by centrifugation.
What are the characteristics of ion-selective electrodes?
The potentiometric selectivity of an electrode is its ability to respond only to the target analyte ion in the presence of other ions. In other words, if the activity of the target ion is the same, the electrode potential and the measured EMF (ideally) are also the same whatever is the composition of the sample.
What is a pH electrode?
pH electrodes are analytical sensors for measuring potential of hydrogen (pH), the negative logarithm of the hydrogen ion activity in solution. The pH value of a substance is directly related to the ratio of the hydrogen ion [H+] and the hydroxyl ion [OH-] concentrations.
Can ion-selective electrodes be used for pH measurements?
The most well-known and highly used ion-selective electrode is a pH electrode, which is sensitive toward the H+ ion. A desirable aspect of ion selective electrodes is their ease of use. Using pH electrodes as an example, after appropriate calibration, it is quite trivial to measure the pH of a solution.
How fluoride inhibits caries formation?
How does fluoride prevent tooth decay?
Fluoride prevents tooth decay by making the enamel more resistant to the action of acids. They and accelerate the buildup of healthy minerals in the enamel, further slowing the occurrence of decay. Studies even show that in some cases, fluoride can stop already started teeth decay.