Glass fritted plate

Filter the petroleum ether extract through 1 or 2 cm. of anhydrous sodium sulfate contained in a glass Buchner funnel equipped with a 30-mm. fritted-glass plate of coarse porosity. This filtration may be carried out rapidly without the aid of suction. (A small amount of filtering aid may be mixed with the sodium sulfate to remove plant pigments.)... 

Filter the cold acetone rapidly into a glass-stoppered test tube by means of suction through a 2- or 3-ml. micro Buchner funnel, fitted with a fritted-glass plate of medium porosity. Wash the tube and funnel with 3 ml. of cold acetone and combine it with the filtrate. 

The hygroscopicity of a propellant is detd rapidly in an apparatus consisting of 2 identical gas washing bottles provided with fritted glass plates near the bottom. The outlets at the bottom are connected through a diaphragm pump... 

Twenty milliliters of petroleum ether is added to precipitate the nitramide. The suspension is stirred with a small porcelain or platinum spatula. The precipitate is filtered on a smooth, hardened filtered paper or fritted glass plate using slight suction. The solid is returned to the bottle by means of the spatula, washed by decantation with 10 ml. of petroleum ether, and filtered. This washing-by-decantation procedure is repeated once more. The funnel is covered with filter paper, and a slow stream of air is drawn through until the product is dry. The nitramide should be in the form of pure white, shiny leaflets. If the product is slightly yellow, it should be dissolved in a minimum amount of anhydrous ethyl ether and reprecipitated with petroleum ether as above. Theoretical yield 3.1 g. actual yields 2.3 to 2.6 g. (75 to 85 per cent of theory). 

A particularly satisfactory ruthenium catalyst was prepared as follows. Commercial ruthenium powder was fused with a mixture of potassium hydroxide and potassium nitrate (1 part ruthenium, 10 parts potassium hydroxide, 1 part potassium nitrate) preferably in a silver crucible and stirred with a silver spatula. Pusion was complete after 1 to 2 hours. After cooling, the fused mass was dissolved in water a deep red solution of potassium ruthenate resulted, which was heated to boiling. Methyl alcohol was added dropwise to the boiling solution. The reduction of potassium ruthenate to ruthenium dioxide began with the addition of the first drops and went rapidly to completion. The precipitate settled after a few hours. It was washed on a fritted glass plate, first with water acidified with nitric acid and then with distilled water. Finally the catalyst was dried at 110°C. The reduction to metal proceeds just as smoothly under synthesis conditions as by a hydrogen treatment, which latter is usually required with catalysts of the iron group. 

The hard black rhenium (IV) iodide is transferred to a test tube 30 cm. long and 25 mm. o.d., which has been constricted to about 10-mm. i.d. at the center. Five grams of iodine is placed on the tetraiodide and the tube is evacuated (oil-pump) and sealed. The tube is heated at 350 5° for 8 hours in a furnace. The tube is then adjusted in such a manner that the rhenium(III) iodide which has formed is maintained in one portion in the furnace at 220° while the other portion protrudes from the furnace. The latter portion is allowed to cool slowly at first and is then cooled further by a jet of air. When all the iodine has apparently collected in the cooled portion, the entire tube is allowed to cool to room temperature. The tube is then scored in the center with a file and broken. (Care is taken to effect a break without introducing shards of glass into the product.) The glistening black crystals are transferred onto the fritted-glass plate of a tared crucible and washed with carbon tetrachloride until the washings are colorless. (About 400 ml. of solvent is required.) The product is then rinsed with two 20-ml. portions each of ethanol and ethyl ether and dried at 110°. The yield is 16.3 g. or 83%. Anal. Calcd. for Reis Re, 32.8 1, 67.2. Found Re, 33.0 1,67.0. 

The reaction flask is now replaced with a reflux condenser which is attached to the Ng-generating apparatus (to equalize the pressure). The receiver flask is heated and the ether is distilled throu the fritted glass plate and onto the residue by cooling the receiver flask, the ether is suction-drawn through the residue back into the flask. This operation is repeated until the residue is colorless. On cooling, most of the complex compound crystallizes in the receiver. The crystal slurry thus obtained is recrystallized from a large quantity of ketyl ether or it is extracted... 

The material is reductively decomposed in the apparatus of Fig. 336. The sample is placed over the fritted-glass plate b (which acts as a distributor). When the hydrogen stream is adjusted to 10 liters/hour at STP, the mixed oxalate should form a stable fluidized bed. The temperature is then raised to 350°C. The decomposition takes 150 minutes. 

Fig. 336. Preparation of mixed salt catalysts by fluidized bed decomposition of ojQ gen-containing compounds, a reactor, b fritted-glass plate (distributor), c electric heating coil, d thermometer connectedto an on-off relay in the heater circuit.

After 30 minutes the solid sulfinic acid is separated on a fritted-glass filter. The sulfinic acid is dissolved from the filter by a mixture of 750 ml. of ether and 750 ml, of methylene chloride. The solution is dried over calcium chloride and evaporated to dryness under reduced pressure (bath temperature 25°) (Note 5). The residue is suspended in 50 ml. of water, and small portions of dilute ammonia are added to the well-stirred suspension until it has a pH of 9 (Note 6). Insoluble impurities are separated by filtration, and 2-nitrobenzenesulfinic acid is precipitated from the filtrate by adding 5-ml. portions of 6N hydrochloric acid with cooling the sulfinic acid precipitated by each portion of acid is separately collected on a Buchner funnel (Note 7). The acid, a pale yellow solid, is dried on a clay plate in a vacuum desiccator over potassium hydroxide pellets, m.p. 120-125° (dec.), weight 9.4-14.9 g. (50-80%). If the 2-nitrobenzenesulfinic acid is to be used for the hydrogenation of the next step high purity is required, and it is generally advisable to reprecipitate the acid once more in the same way (Note 8). 

Small filter tube with Jena glass fritted filter plate (13 f. G 2). 

Figure 17.11 Transmission spectroelectrochemistry cell designed for use with room-temperature haloaluminate melts and other moisture-reactive, corrosive liquids, (a) Auxiliary electrode and reference electrode compartments, (b) quartz cuvette containing the RVC-OTE, (c) brass clamping screw, (d) passageway between the separator and OTE compartment, (e) fritted glass separator, (f) A1 plate, (g) lower cell body (Teflon), (h) upper cell body (Teflon). This cell is normally used inside a glove box and is optically accessed with fiber optic waveguides. [From E. H. Ward and C. L. Hussey, Anal. Chem. 59 213 (1987), with permission.]...

The reactions are carried out in a 1-1. round-bottomed flask (Fig. 18) sealed to a dropping funnel and a gas inlet tube A.% The neck of the flask is closed with a rubber stopper bearing a gas inlet C and an outlet tube B (i.d. at least 5 mm.). The latter is connected to a filter assembly which consists of a 25-mm.-i.d. filter tube with a fritted-glass filter plate D (porosity B). The distance from the filter plate to the top of the tube should be at least 35 cm. As shown in Fig. 18, tubes B and C extend into the flask through glass sleeves and are attached to these sleeves by means of rubber tubing so that B and C may be raised or lowered. 

Frit-inlet asymmetrical flow field-flow fractionation (FIA-FIFFF) [1-3] utilizes the frit-inlet injection technique, with an asymmetrical flow FFF channel which has one porous wall at the bottom and an upper wall that is replaced by a glass plate. In an asymmetrical flow FFF channel, channel flow is divided into two parts axial flow for driving sample components toward a detector, and the cross-flow, which penetrates through the bottom of the channel wall [4,5], Thus, the field (driving force of separation) is created by the movement of cross-flow, which is constantly lost through the porous wall of the channel bottom. FlA-FlFFF has been developed to utilize the stopless sample injection technique with the conventional asymmetrical channel by implementing an inlet frit nearby the channel inlet end and to reduce possible flow imperfections caused by the porous walls. 

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