Column chromatography elution

An aqueous solution of NaCl, NaN03, and Na2S04 was passed through a Cig-silica reversed-phase liquid chromatography column eluted with water. None of the cations or anions is retained by the Cjg stationary phase, so all three salts were eluted in a single, sharp band with a retention time of 0.9 min. Then the column was equilibrated with aqueous 10 mM pentylammonium formate, whose hydrophobic tail is soluble in the C18 stationary phase. 

Clemo-McQuillen pycnometer, 49 color tests, 631, 649, 653 column chromatography. See also chromatography column elution, 94-95 column packing, 93-94 defined, 92 fraction collection, 95 materials, 92-93 sample application, 94 column holdup, 65 columns... 

In the continuous process for producing phosphatidylcholine fractions with 70—96% PC at a capacity of 600 t/yr (Pig. 5) (16), lecithin is continuously extracted with ethanol at 80°C. After separation the ethanol-insoluble fraction is separated. The ethanol-soluble fraction mns into a chromatography column and is eluted with ethanol at 100°C. The phosphatidylcholine solution is concentrated and dried. The pure phosphatidylcholine is separated as dry sticky material. This material can be granulated (17). 

Cyclohexylidene fulvene [3141-04-6] M 134.2. Purified by column chromatography and eluted with -hexane [Abboud el al. J Am Chem Soc 109 1334 1987]. 

Diazocamphor A large wide-diameter chromatography column (8.5 cm diameter) is packed with 1000 g of basic chromatography grade alumina. The previously prepared solution of the monotosylhydrazone is filtered, if necessary, to remove solids, then poured directly onto the alumina, and the column is eluted with chloroform. The solution of diazocamphor thus obtained is evaporated yielding the desired product. It may be recrystallized from hexane, mp IS. ... 

A variety of chromatographic techniques are now in common use, all of which work on a similar principle. The mixture to be separated is dissolved in a solvent, called the mobile phase, and passed over an adsorbent material, called the stationary phase. Because different compounds adsorb to the stationary phase to different extents, they migrate along the phase at different rates and are separated as they emerge (elute) from the end of the chromatography column. 

In the ion-exchange technique, separated amino acids exiting (eluting) from the end of the chromatography column mix with a solution of ninhydrin and undergo a rapid reaction that produces an intense purple color. The color is detected by a spectrometer, and a plot of elution time versus spectrometer absorbance is obtained. 

Elution (Chapter 12 Focus On) The removal of a substance from a chromatography column. 

A chromatography column of 4.5-cm diameter was charged with 250 g of silica gel (ICN Silica 10/18 60 A). The viscous oily crude product is dissolved in 10 mL of methylene chloride, 10 g of silica gel is added, and the solvent is evaporated. The resulting dry powder is applied on the top of the column which is then successively eluted with petroleum ether, 95 5 petroleum ether/acetone, and 90 10 petroleum ether/acetone. 

All the solutes in exclusion chromatography are eluted between the interstitial column volume and the column dead volume (i.e. the pore volume). Consequently, the column must be large enough to provide... 

Reversed-phase Cig chromatography column. Keystone Scientific Betasil, 100 x 2.0-mm i.d., 5-pm particle size, 100 A, Part No. 105-701-2-CPF TSQ 7000 LC/MS/MS system with electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI) interface and gradient high-performance liquid chromatography (HPLC) unit, or equivalent Vacuum manifold for use with SPE cartridges (Varian Vac Elut 10 or equivalent)... 

A glass chromatography column (1.5-cm i.d., 30-cm length) is filled with 10 g of Florisil using a solution of diethyl ether-n-hexane (3 17, v/v) and 5 g of anhydrous sodium sulfate are placed on the top of the Florisil. The residual sample obtained in Section 5.3 is dissolved in 10 mL of diethyl ether-n-hexane (3 17, v/v) and transferred on to the column and 100 mL of diethyl ether-n-hexane (3 17, v/v) are added as eluent and discarded. Using 100 mL of diethyl ether-n-hexane (3 7, v/v), isoxathion is eluted. The eluate is collected and concentrated under reduced pressure below 40 °C. 

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