Hyflo Supercel

Systems such as Pseudomonas lipase dispersed inside Hyflo Supercell (a diatoma-ceous silica of pH 8.5-9) and SP 435 Novozym (Candida antarctica lipase grafted on an acrylic resin) are thermally stable and have optimum activity in the range 80-100 °C. They can therefore be used with conventional or microwave heating if the temperature is strictly controlled. 

Hyflo Supercel, a filter aid purchased from Johns-Manville Corporation, was used by the checkers. 

Upon determination of the completion of the reaction 20.0 g of 10 wt. % of aqueous sodium hydrogen sulfate solution was added in one portion, and the resultant admixture stirred for 10 min at ambient temperature. The batch was then concentrated in vacuo at 45°C to dryness. Subsequently water (180 g), toluene (69 g), ethyl acetate (36 g) were added and vigorous stirring for about 10 min undertaken. The resulting layers were separated and the aqueous layer saved in a flask. The organic layer was washed thrice with a solution of 26 ml of 2.5% HCI. The combined aqueous layers were then filtered through a pad of wet (with water) hyflo-supercel filter aid. Subsequently, EtOAc (85 g) was added to the filtrate and concentrated... 

Upon the reaction was complete, the batch was cooled to ambient temperature under the nitrogen atmosphere, and the contents filtered over a hyflo-supercel filtering pad (3.0 g, wetted with water). The flask and wet cake were rinsed with acetic acid (20 g). The filtrate was concentrated in vacuo to... 

To a suspension of 6-chloropyrido[2,3-6]pyrazine-2-hydrazine (6 1.9 g, 10 mmol) in CHC1, (100 mL) was added freshly prepared Mn02 on carbon catalyst in small portions at rt. under vigorous stirring. After the addition had been completed, the solvent was refluxed for 2 h. The suspension was filtered, while still hot, over Hyflo Supercel. The solid material was extracted with hot CHCI, (100 mL). The combined extracts were dried (MgS04), filtered and the solvent removed (in vacuo) yield 1.2 g (70%). The product was recrystallized (H20). 

Often a small amount of insoluble, dark-brown material remains in suspension. Filtration of this product is most difficult, since it tends to clog the filter paper. It seems advisable to change filter papers two or three times during the filtration, if necessary. This step usually requires from 30 minutes to 1.5 hours however, the time can be shortened appreciably by the use of Hyflo Supercel . 

To MCI, (1 g) dissolved in the minimum volume of water is added AgCFjSOs (n equiv). The solution is stirred rapidly for 5-10 min, and the precipitated AgCl is removed by vacuum filtration through a bed of Hyflo Supercel (Gallard Schlesinger) on a sintered-glass funnel. Isolation and purification procedures are the same as described in Sections A and B. 

Without prior fractionation the total concentration of carotenoids ( total carotenes ) in a sample extract may be estimated by spectrophotometry at 450 nm (using an average molar absorptivity for calculation). As an improvement, in earlier times, individual carotenoids or carotenoid classes were collected after separation on alumina or magnesia-hyflo supercel columns and the absorbance of the eluted fractions measured. This approach once formed the basis of the Association of Official Analytical Chemists (AOAC) method for foods. 

Reversed phase partition systems have been described both for conjugated and free bile acids (1) (straight phase systems for free bile acids are described in Section III.B.2). Suitable solvent systems are summarized in Table I. Three types of support have been employed acid-washed siliconized Hyflo Supercel, Hostalen, and methylated Sephadex (1, 40). The first-mentioned type is the most versatile one for two-phase solvent systems. The Sephadex derivative should be used only with solvents of the C-type this material is designed for use with miscible solvent systems (see Section III. B.3). The mobility of some bile acids in different two-phase systems are shown in Table II. These values refer to use of Hyflo Super-Cel which takes up 4 ml stationary phase/4.5 g retention volumes are smaller with Hostalen (3 ml/4.5 g) and larger with methyl Sephadex (6 ml/4.5 g). A 4.5 g Supercel column should not be loaded with more than 25-30 mg of material—flow rate should be about 0.3-0.6 ml/min/cm column cross sectional area. The... 

TABLE II. Approximate Retention Volumes of Bile Acids in Reversed Phase Liquid-Liquid Partition Chromatography on Hydrophobic Hyflo Supercel ... 

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