Diatomaceous Silica Celite

The filter cake is stirred with 3.1 liters of acetone. The volume of acetone used is about 1.5 times the weight of the cake resulting in about a 65% acetone concentration. The benzoic acid dissolves in the acetone and the urokinase flocculates out. Sodium benzoate, about 1% of the weight of the cake, or 21 grams, is added to speed up the formation of the precipitate. The suspension of crude urokinase in acetone Is filtered on a Buchner funnel using filter paper precoated with a diatomaceous silica product (Celite 505). The precipitate is washed with acetone until the filtrate is water clear. The precipitate is then washed with ether and air dried. The yield of powder so obtained is 2.3 grams. 

SYNS AMORPHOUS silica CELITE D.E. DIATOMACEOUS EARTH, NATURAL DIATOMACEOUS SILICA DIATOMITE ... 

Celite, a Johns-Manville registered trademark for a diatomaceous silica product. It is used as a filter aid. Supplier Fisher. Bernstein recommends that a water-washed benzene extract of a reaction product be filtered through a small pad of Celite and evaporated without further drying. 

These are prepared from flux-calcined diatomaceous earth, also called diatomite, diatomaceous silica, or kieselguhr. This earth is composed of the skeletons of diatoms, which are single-celled algae. It is excavated from deposits found in various parts of the world. The calcining is carried out by mixing the earth with a little sodium carbonate (called the flux), and raising the temperature to above 900°C. Various white diatomaceous earths are available commercially. The more common of these are Anak-rom U, Celite 545, Chromosorb G (very robust material), Chromosorb W, Gas-Chrom CL, Gas-Chrom P, and Gas-Chrom S. 

Celite . [Celite] Diatomaceous silica filter aids, catalyst carriers, filler, extender pigment, grinding aid, conditioner, processing aid, flatting agent for paints, agric. chonicals, paper, rubber, polishes, cleaners. 

Numerous inorganic and organic materials have been used as carriers activated charcoal [375], alumina [376], silica [377, 378], diatomaceous earth (Celite) [165, 379], cellulose [380], controUed-pore glass, and synthetic resins [381]. In contrast to the majority of enzymes, which preferably adsorb to materials having a polar surface, lipases are better adsorbed onto lipophilic carriers due to their peculiar physicochemical character (Sect. 2.1.3.2) [72, 382-385]. Adsorption is the method of choice when enzymes are used in lipophilic organic solvents, where desorptiOTi cannot occur due to their insolubility in these media. 

Diatomaceous silica is also known as d. earth, diatomite, infusorial earth, kieselguhr and tripohte modem trade names include Celite, Celatom, Dicalite, Kenite and Aquafil (Kranich). It is Usted by the Colour Index as Cl 77811/Pigment White 27. 

Atomite - 3.0pm calcimn carbonate (ECC America Inc.) Celite 281 - diatomaceous silica (Cehte Corp.)... 

Mix equivalent weights of silica gel 60 GF254 (Merck) and diatomaceous earth (Hyflo Super-Cel Celite, World Minerals) in a mechanical blender or in a large plastic bag for 2 hr. Store <3 months in a sealed container at room temperature. 

A solution of chromium trioxide in dilute sulfuric acid used in aqueous acetone is called Jones reagent [572]. Other solvents of chromium trioxide are ether [535] and hexamethylphosphoric triamide (HMPA) [543. Oxidations are also carried out with chromium trioxide adsorbed on Celite (diatomaceous earth) [53S], silica gel [537], or an ion exchanger such as Amberlyst A26 (a macroreticular quaternary ammonium salt anion exchanger) [571, 617]. Such oxidations often take place at room temperature and can be used not only for saturated alcohols but also for unsaturated and aromatic alcohols (equations 208 and 209). 

The supports most commonly used are silica gel (sometimes referred to as silicic acid), diatomaceous earths (kieselguhr, celite, etc.) and cellulose. Other solids such as starch or glass beads have found more limited use. 

As described previously, the silica carrier was the FC Celite (Manville), a macroporous diatomaceous earth, with 1 wt-% alumina. The total surface area of the Celite was 45 m /g and the porous volume (essentially macroporous) was 1.0 cm /g, with a mesopore volume contribution of only 0.1 cm /g. 

Silica itself (the simplest silicate ) has found tittle use in PVC because of its abra-sivity (Mohs hardness of 7) and its acidity (pH 6-6.5), having been superseded as an antiblocking agent by zeolite and various silicates. An exception is diatomaceous amorphous silica, which, in synthetic forms (Celite ) and as naturally occurring diatomaceous earth, is often used as the carrier in dry Uquid dispersions. Diatomite is less abrasive than other forms of silica (Mohs hardness of 5-6) and is pH-neutral. It is an excellent solid carrier for polymeric plasticizers of viscosity high enough to make handling difficult. 

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