Chromatography filters

Chromatography. Filtered polysaccharide solutions were analyzed using an SEC system consisting of an automatic sampler (Waters WISP, Waters, Milford, MA) with a high-performance liquid chromatography pump (Waters model 590), pulse dampener (Viscotek, Houston, TX), viscometer... 

There are otlier teclmiques for mass separation such as tire quadmpole mass filter and Wien filter. Anotlier mass spectrometry teclmique is based on ion chromatography, which is also capable of measuring tire shapes of clusters [30, 31]. In tills metliod, cluster ions of a given mass are injected into a drift tube witli well-defined entrance and exit slits and filled witli an inert gas. The clusters drift tlirough tills tube under a weak electric potential. Since the... 

With Stirring, hydrazine hydrate (4 ml in 30 ml of THh ) was added over 60 min. The reaction mixture was then cooled to room temperature and filtered through Celite. The filtrate was concentrated in vacuo and the residue purified by chromatography through silica gel using 10% ether in hexane for elution. The fractions containing product were combined and evaporated to give the product as a clear oil (2.94g, 50%). 

Lipoproteins may denature on heating and if present during pasteurization can result in the formation of haze or turbidity in the final product. This material was removed traditionally by filtration through asbestos (qv) sheets (6) however, health hazards associated with asbestos have led to its replacement by alternative filter materials (23,37,193). These media have been less effective than asbestos and further measures have been required to ensure the visual clarity of albumin products, eg, further filtration developments for Hpid removal (194), preferential denaturation of contaminants using in-process heat treatment, and anion-exchange chromatography (49). 

Aluminum compounds, particularly the hydroxides and oxides are very versatile. Properties range from a hardness iadicative of sapphire and comndum to a softness similar to that of talc [14807-96-6] and from iuertness to marked reactivity. Aluminas that flow and filter like sand may be used for chromatography (qv) others are viscous, thick, unfilterable, and even thixotropic (1). 

Sodium and chloride may be measured using ion-selective electrodes (see Electro analytical techniques). On-line monitors exist for these ions. Sihca and phosphate may be monitored colorimetricaHy. Iron is usually monitored by analysis of filters that have had a measured amount of water flow through them. Chloride, sulfate, phosphate, and other anions may be monitored by ion chromatography using chemical suppression. On-line ion chromatography is used at many nuclear power plants. 

Nltroestrone (2)/ Claylen was prepared from a mixture of Fe(N03)3 H2O (45 g Oil mol), K 10 bentonite clay and MeaCO (750 mL) Freshly prepared Claylen" (2 0 g) was added to estrone 1 (0 54 g 2 mmol) and PhMe (150 mL) The suspension was slirred overnight at 20° and filtered under vacuum The yellow liltraie was purified by column chromatography on sdica gel (n-hexane ElOAc 8 2] Evaporation of the corresponding fraction afforded 0 347 g of 2 (55%) mp 178 180°C... 

The mixture is dned (Na2S04), filtered (celite pad) arxJ evaporaled Chromatography (alumina 2% Et20 in pentane) afforded 144 mg of 5 (96%)... 

Graded Adsorbents and Solvents. Materials used in columns for adsorption chromatography are grouped in Table 12 in an approximate order of effectiveness. Other adsorbents sometimes used include barium carbonate, calcium sulfate, calcium phosphate, charcoal (usually mixed with Kieselguhr or other form of diatomaceous earth, for example, the filter aid Celite) and cellulose. The alumina can be prepared in several grades of activity (see below). 

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