| HELIUM SPARGING:
the bubbling of helium through the mobile phase to remove
dissolved air. See DEGASSING.
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| HIGH-PRESSURE MIXING: a pumping procedure in which two
or more different solvents are mixed on the high pressure
side of the pump to form a final mobile phase. Generally
one pump is required for each solvent, so such systems
are often referred to as "two-pump" systems. See also LOW-PRESSURE MIXING.
|
 Waters 2-pump gradient system
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| HPLC or HIGH-PERFORMANCE
LIQUID CHROMATOGRAPHY: a special application of liquid
chromatography using instrumentation to allow complex
separations and analyses to be carried out in very short
times. Also often called HIGH-PRESSURE LIQUID
CHROMATOGRAPHY, it is distinguished from "classical"
or "open-column" liquid chromatography in which
mobile phase flows through the column by gravity only. It
is also called "LC" for short.
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| HYDROPHILIC: "water-loving";
refers to compounds, solvents or bonded phases that
either dissolve easily in water or prefer water to
nonpolar organic solvents. See HYDROPHOBIC.
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| HYDROPHOBIC:
"water-hating"; refers to compounds, solvents
or bonded phases that either dissolve easily in nonpolar organic solvents such as hexane, or
prefer such solvents to water. See HYDROPHILIC.
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