Drop chromatography

This is invariably referred to in various literature as open-column chromatography drop chromatography strip-chromatography spread-layer chromatography surface chromatography . 

Izmailov, N.A. Shraiber MS (1938) The application of analysis by drop chromatography to pharmacy. Farmezia 3 1... 

In 1938, N. A. Ismailov and M. S. Shraiber [313] described the basic principle of the procedure in an article entitled Analysis by Drop-chromatography and its Application in Pharmacy . They applied the method to the separation and characterisation of extracts of medicinal plants (tinctures of the Soviet Pharmacopoeia VII). 

DROP CHROMATOGRAPHY. Application of a drop of mixture solution to a layer, followed by applications of drops of a solvent on top of the sample to develop it into concentric rings. 

Elution volume, exclusion chromatography Flow rate, column Gas/liquid volume ratio Inner column volume Interstitial (outer) volume Kovats retention indices Matrix volume Net retention volume Obstruction factor Packing uniformity factor Particle diameter Partition coefficient Partition ratio Peak asymmetry factor Peak resolution Plate height Plate number Porosity, column Pressure, column inlet Presure, column outlet Pressure drop... 

Rhodamine B chloride [3,5-his-(diethylamino)-9-(2-carboxyphenyl)xanthylium chloride] [81-88-9] M 479.0, m 210-211"(dec), Cl 45170, A,max 543nm, Free base [509-34-2] Cl 749, pK 5.53. Major impurities are partially dealkylated compounds not removed by crystn. Purified by chromatography, using ethyl acetate/isopropanol/ammonia (conc)(9 7 4, Rp 0.75 on Kieselgel G). Also crystd from cone soln in MeOH by slow addition of dry diethyl ether or from EtOH containing a drop of cone HCl by slow addition of ten volumes of dry diethyl ether. The solid was washed with ether and air dried. The dried material has also been extracted with benzene to remove oil-soluble material prior to recrystn. Store in the dark. 

As a general procedure, a mixture of the steroidal ketone (50 mg) and lithium aluminum deuteride (20 mg) in dry ether (5 ml, freshly distilled from lithium aluminum hydride) is heated under reflux until the reduction is complete according to thin layer chromatography test. The excess deuteride is then decomposed by the careful addition of a few drops of water and the reaction mixture is worked up by the usual procedure. For hindered ketones or esters the use of other solvents, such as tetrahydrofuran or dioxane, may be preferable to allow higher reaction temperatures. 

Ethoxymethyl)phthalonitriie (12 2,88 g, 15.5 mmol), Fe(OAc)2 (672 mg, 3.9 mmol), and two drops of DBU were heated in anhyd hexan-l-ol (120 mL) at 150rC until all the phthalonitrile had reacted (TLC). The mixture was cooled and the solvent was removed under reduced pressure. The residue was washed with McOH and purified by column chromatography [neutral alumina (deactivated with 4% H,0), CHC1, ... 

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