What are selectivity coefficients?
What are selectivity coefficients?
A selectivity coefficient is the equilibrium constant for the reaction of displacement by one ligand of another ligand in a complex with the substrate. Binding selectivity is of major importance in biochemistry and in chemical separation processes.
What does a high selectivity coefficient mean?
For reference: Definition of selectivity coefficient Higher concentrations of target ions result in the interfering ions having a smaller effect, and conversely, lower concentrations result in them having a larger effect. An ion selective electrode has its own operable pH range.
What is selectivity coefficient in ion exchange?
Ion exchange resins, when placed in a solution, reach an equilibrium state between ions in the solution and ions on the resin. ions on the resin. These selectivity coefficients are a measurement of a resins preference for an ion. The greater the selectivity coefficient, the greater the preference for the ion.
What is potentiometric selectivity coefficient?
https://doi.org/10.1351/goldbook.P04791. A. coefficient. which defines the ability of an ion-selective electrode to distinguish a particular ion from others.
What’s the definition of selectivity?
selectivity. / (sɪˌlɛkˈtɪvɪtɪ) / noun. the state or quality of being selective. the degree to which a radio receiver or other circuit can respond to and separate the frequency of a desired signal from other frequencies by tuning.
What is selectivity in chemistry?
Selectivity is the discrimination shown by a reagent in competitive attack on two or more substrates or on two or more positions in the same substrate. It is quantitatively expressed by ratios of rate constants of the competing reactions, or by the logarithms of these ratios.
What is the selectivity of a drug?
Selectivity is the degree to which a drug acts on a given site relative to other sites. Relatively nonselective drugs affect many different tissues or organs. For example, atropine, a drug given to relax muscles in the digestive tract, may also relax muscles in the eyes and in the respiratory tract.
How is drug selectivity determined?
Selectivity is defined as the ratio of the affinity of the compound towards the off-target protein relative to the target protein (Kd ratio = Kd,off target/Kd,target). The larger the Kd ratio, the better the selectivity.
What factors affect the selectivity of ion exchangers?
Examples are given in anion-exchange chromatography to show the effect of variations in the geometry, bulkiness and polarity of the resin cation on selectivity. The type of resin matrix, the hydrophobic nature of the resin surface and the degree of solvation also affect chromatographic behavior.
What 3 factors affect the selectivity of ion exchangers?
The factors that affect separation during ion exchange chromatography include the surface area of the stationary phase (resin bead size); the density of exchange sites on the stationary phase surface (cross-linkage); the flow rate of the mobile phase (resin bead size and column geometry; system pressure in high- …
What is the principle of ion selective electrode?
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 type of an electrode is F selective electrode?
A fluoride selective electrode is a type of ion selective electrode sensitive to the concentration of the fluoride ion. A common example is the lanthanum fluoride electrode.
What does the selectivity coefficient mean in a circuit?
The selectivity coefficients is the approximate apparent increase caused by the interfering ion. A selectivity coefficient of 0.1, for example, implies that the electrode is ten times more responsive to the primary ion than to the interfering ion.
What is the difference between selectivity and specificity?
Selectivity or specificity The terms selectivity or specificity are in many cases used interchangeably. As specificity is considered as an absolute term, it cannot be graded. IUPAC has earlier stated that “specificity is the ultimate of selectivity”.
Which is an example of a coefficient in math?
Coefficient. more A number used to multiply a variable. Example: 6z means 6 times z, and “z” is a variable, so 6 is a coefficient. Variables with no number have a coefficient of 1. Example: x is really 1x. Sometimes a letter stands in for the number.
Which is an example of a selectivity method?
Selectivities in methods. Current analytical methods are based on multistage separation and detection principles. Metals are often determined with methods based on detection selectivity, e.g, atomic emission spectrometry. Separation techniques for all types of species rely on selectivity in the separation process, separation selectivity.