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Acetonitrile has only modest toxicity in small doses. [11] [19] It can be metabolised to produce hydrogen cyanide, which is the source of the observed toxic effects. [9] [20] [21] Generally the onset of toxic effects is delayed, due to the time required for the body to metabolize acetonitrile to cyanide (generally about 2–12 hours). [11]
Supercritical fluid chromatography (SFC) [1] is a form of normal phase chromatography that uses a supercritical fluid such as carbon dioxide as the mobile phase. [2] [3] It is used for the analysis and purification of low to moderate molecular weight, thermally labile molecules and can also be used for the separation of chiral compounds.
Sparging introduces a gas that has little or no partial pressure of the gas(es) to be removed, and increases the area of the gas-liquid interface, which encourages some of the dissolved gas(es) to diffuse into the sparging gas before the sparging gas escapes from the liquid. Many sparging processes, such as solvent removal, use air as the ...
[7] [27] The added organic solvents must be miscible with water, and the two most common organic solvents used are acetonitrile and methanol. Other solvents can also be used such as ethanol or 2-propanol (isopropyl alcohol) and tetrahydrofuran (THF). The organic solvent is called also a modifier, since it is added to the aqueous solution in the ...
Gas properties Std enthalpy change ... Vapor-liquid Equilibrium for Acetonitrile/Toluene [4] P = 760 mmHg BP Temp. °C % by mole toluene liquid vapor 81.5: 3.3: 5.1
The chiral stationary phase, CSP, can interact differently with two enantiomers, by a process known as chiral recognition. Chiral recognition depends on various interactions such as hydrogen bonding, π-π interaction, dipole stacking, inclusion complexation, steric, hydrophobic and electrostatic interaction, charge-transfer interactions, ionic interactions etc, between the analyte and the CSP ...
The mobile phase is dependent on the absorptivity of the stationary phase and the composition of the compound of interest. [5] The compound is first tested with solutions such as diethyl ether, ethanol, dichloromethane, chloroform for normal phase HPTLC, or solutions such as methanol, acetonitrile, and tetrahydrofuran for
For extremely polar analytes (e.g. aminoglycoside antibiotics or adenosine triphosphate), higher concentrations of buffer (c. 100 mM) are required to ensure that the analyte will be in a single ionic form. Otherwise, asymmetric peak shape, chromatographic tailing, and/or poor recovery from the stationary phase will be observed.