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Hydrophilic interaction chromatography (or hydrophilic interaction liquid chromatography, HILIC) [1] is a variant of normal phase liquid chromatography that partly overlaps with other chromatographic applications such as ion chromatography and reversed phase liquid chromatography. HILIC uses hydrophilic stationary phases with reversed-phase ...
The bottom of the paper device is inserted into a sample solution prepared in-lab, and the amount of color change is observed. [62] More recently, a paper-based microfluidic device using colorimetric detection was developed to quantify glucose in blood plasma.
An example of these amphiphilic molecules is the lipids that comprise the cell membrane. Another example is soap, which has a hydrophilic head and a hydrophobic tail, allowing it to dissolve in both water and oil. Hydrophilic and hydrophobic molecules are also known as polar molecules and nonpolar molecules, respectively. Some hydrophilic ...
For such sensitive cases there is a test for the metal content of a column is to inject a sample which is a mixture of 2,2'- and 4,4'-bipyridine. Because the 2,2'-bipy can chelate the metal, the shape of the peak for the 2,2'-bipy will be distorted (tailed) when metal ions are present on the surface of the silica .
The effect originates from the disruption of highly dynamic hydrogen bonds between molecules of liquid water. Polar chemical groups, such as OH group in methanol do not cause the hydrophobic effect. However, a pure hydrocarbon molecule, for example hexane, cannot accept or donate hydrogen bonds to water. Introduction of hexane into water causes ...
The behavior of fluids and their control in open microchannels was pioneered around 2005 [11] and applied in air-to-liquid sample collection [12] [13] and chromatography. [14] In open microfluidics , at least one boundary of the system is removed, exposing the fluid to air or another interface (i.e. liquid).
HLB scale showing classification of surfactant function. The hydrophilic–lipophilic balance (HLB) of a surfactant is a measure of its degree of hydrophilicity or lipophilicity, determined by calculating percentages of molecular weights for the hydrophilic and lipophilic portions of the surfactant molecule, as described by Griffin in 1949 [1] [2] and 1954. [3]
For example, the blood/gas partition coefficient of a general anesthetic measures how easily the anesthetic passes from gas to blood. [5] Partition coefficients can also be defined when one of the phases is solid , for instance, when one phase is a molten metal and the second is a solid metal, [ 6 ] or when both phases are solids. [ 7 ]