Frit porosity

Double-ended filter (frit porosity 3) with two male joints... 

Fig. 1. Electrochemical cell for the removal of residual silver ion. The cathode is a cylindrical platinum net electrode (18 X 40 mm) and the anode is a 20 X 40 mm platinum sheet. A Kimble fine frit (porosity 4-5.5) separates the anode from the cathode compartment. The checker has added a vent to the anode compartment to remove H2. A self-regulating power supply such as the Tektronix PS 501-2 works well.

Meanwhile, the thermometer and stirrer of the reaction flask are replaced with stoppers and the condenser with a drying tube while the system is purged with argon or nitrogen. The reaction flask is then filled with 400 mL of dry diethyl ether and shaken to wash the product from the potassium salts. In order to filter the resulting solution, the drying tube is replaced with a fritted funnel (50-mm diameter coarse glass frit, porosity 3), which is connected to a vertical vacuum adapter topped by a 1-L two-necked flask. The apparatus is then inverted as the... 

Standard two-compartment H cell. The catholyte consisted of 3.25 M nitric acid and was separated by a medium-porosity sintered glass frit. Experiments were also carried out to determine if surface oxidation of hydrocarbon polymers could be obtained in an electrolyte consisting only of nitric acid. 

The reaction mixture is diluted with 250 ml of water, the mixture is transferred to a 2 liter flask using methanol as a wash liquid, and the organic solvents are distilled at 20-25 mm using a rotary vacuum evaporator. The product separates as a solid and distillation is continued until most of the residual toluene has been removed. The solid is collected on a 90 cm, medium porosity, fritted glass Buchner funnel and washed well with cold water. After the material has been sucked dry, it is covered with a little cold methanol, the mixture is stirred to break up lumps, and the slurry is kept for 5 min. The vacuum is reapplied, the solid is rinsed with a little methanol followed by ether, and the material is air-dried to give 9.1 g (85%), mp 207-213° after sintering at ca. 198°. Reported mp 212-213°. The crude material contains 1.0-1.5% of unreduced starting material as shown by the UV spectrum. Further purification may be effected by crystallization from methanol. 

The filtering operation can also be conveniently done in a high-quality nitrogen atmosphere dry box by vacuum filtration through a 90-mm., 60-ml., medium-porosity fritted-disk Buchner funnel. 

FIGURE 8.2 Sample recovery tube for recovery of samples from PLC plates (Catalog No. 416400-0023). The approximate bulb capacity is 25 to 30 ml, overall length 180 mm, and fritted disc porosity coarse. (Photograph supplied by Kimble/Kontes, Vineland, NJ.)... 

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. 

Products in the reaction mixture were analyzed by infrared and nmr spectroscopy. IR spectra were obtained on a Perkin-Elmer 521 infrared spectrophotometer. The reaction mixture was first suction filtered through a fine porosity glass frit inside a glove box (Vacuum Atmosphere HE-43-2) under an argon atmosphere, and was placed in NaCl cells (International Crystals, Inc.) of path length 0.1 or 0.5 cm with Teflon stoppers. H nmr spectra... 

An extractor of 2-1. capacity with fritted disc of 85 mm. diameter and coarse porosity was used (Figure 2). 

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