Filtration apparatus

The complete filtration apparatus is shown in Fig. 5, p. 11. A simpler and cheaper apparatus is shown in Fig. 45. This consists of a boiling-tube A having a side-arm for connection to the pump the tube A is conveniently held in a wooden or cork block B or in a clamp. The funnel F may be fitted into A through a pliable rubber disc D the latter is more useful than a cork since it covers tubes of various diameters. The filtrate is collected in the centrifuge-tube T. 

The way the chemist knows that she has methylamine and not ammonium chloride is that she compares the look of the two types of crystals. Ammonium chloride crystals that come from this reaction are white, tiny and fuzzy. The methylamine hydrochloride crystals are longer, more crystalline in nature and are a lot more sparkly. The chemist leaves the methylamine crystals in the Buchner funnel of the vacuum filtration apparatus and returns the filtrate to the distillation set up so it can be reduced one last time to afford a second crop. The combined methylamine hydrochloride filter cake is washed with a little chloroform, scraped into a beaker of hot ethanol and chilled. The methylamine hydrochloride that recrystallizes in the cold ethanol is vacuum filtered to afford clean, happy product (yield=50%). 

As soon as the receiver containing the methyl 11 thiurn solution has been removed and stoppered, the residual solids in the reaction flask and the filtration apparatus should be rinsed Into another receiver with anhydrous ether under an atmosphere of argon or nitrogen. The ether slurry of solids, which may contain some unchanged lithium metal, should be treated cautiously in a hood with t-butyl alcohol to consume any residual lithium metal before the mixture is discarded. 

Filtration apparatus is available to remove any size, but the very fine particles require a deep, bulky and expensive filter, which itself sets up a high resistance to air flow and therefore requires high fan power. A practical balance must be reached to satisfy the requirements ... 

A slow stream of dry nitrogen was passed through an inverted funnel that was placed over the filtration apparatus. 

A water sample is usually analyzed as it is, but is filtered through a glass-fiber filter to remove SS or to analyze both water and SS separately when chemicals adsorbed on SS used to be determined for a special purpose of a study. All filtration apparatus should be washed with the sample water in order to avoid contamination. 

Prepare 500 mL of a mobile phase that is 25 mM KC1, 5 mM MgCl2, and 50 mM tris-(hydroxym-ethyljamino methane (TRIS or THAM). Adjust the pH to 7.2 using concentrated HC1. Filter and degas this mobile phase using a vacuum filtration apparatus equipped with 0.45-/LL filters. 

Use the ring stand, small iron ring, funnel, Erlenmeyer flask, and filter paper to set up a filtration apparatus. Attach the iron ring to the ring stand. Adjust the height of the ring so the end of the funnel is inside the neck of the Erlenmeyer flask. 

To prepare [(C4H9)4N] [B2H3(C4Hs)2], THF is withdrawn from the reaction mixture by means of a vacuum line until the volume remaining is 5 mL. The capped vessel is then removed from the vacuum line, and a 6.40-mmole (2.357 g) sample of f(C4H9)4N] I is added to the open end of the valve. The vessel is attached to a fine-frit, vacuum-line filtration apparatus (Fig. 2), and the system... 

Figure 3. Schematic diagram of the filtration apparatus. The volume in the holding cell was held constant as permeate was replaced by fresh borate-containing feed. Boron concentration and pH were monitored in die permeate.

Polymer-Assisted Ultrafiltration of Boric Acid. The Quickstand (AGT, Needham, MA) filtration apparatus is pictured schematically in Figure 3. The hollow fiber membrane module contained approximately 30 fibers with 0.5 mm internal diameter and had a nominal molecular weight cut-off of 10,000 and a surface area of 0.015 m2. A pinch clamp in the retentate recycle line was used to supply back pressure to the system. In a typical run, the transmembrane pressure was maintained at 25 psig and the retentate and permeate flow rates were 25 ml/min and 3 ml/min, respectively. Permeate flux remained constant throughout the experiments. 

The method is readily adapted for the preparation of conjugates starting with between 20 and 50 mg of antibody by using columns of the same length but increased id (2.6 cm) and an ultrafiltration cell with 50 mL capacity For preparations using less than 5 mg of antibody, HPLC gel filtration apparatus is more suitable for purification purposes... 

Figure 19.5 Schematic diagram of a filtration apparatus used in radiochemistry.

Vacuum filtration apparatus with 0.45-pm membrane Spectrophotometer (285 to 456 nm)... 

Filtration apparatus, for collecting acid precipitates on nitrocellulose filters or membranes... 

A. Vacuum Line Filtration. For their work on the diammoniate of dibo-rane. Parry, Schultz, and Girardot24 devised a versatile vacuum line filtration apparatus which is useful when small quantities of solid are handled and when the solvent is sufficiently volatile to be distilled on the vacuum line. The filter is attached to the vacuum system through a standard taper joint which allows it to be rocked or inverted (Fig. 9.21). Prior to filtration, any volatile contents are frozen down and the apparatus is thoroughly evacuated (Fig. 9.21a). By inversion of the apparatus, the solution is then poured onto the frit, and the solvent vapor pressure is employed to effect a suction filtration by closing the stopcock in the equalizing arm and cooling the lower tube (Fig. 9.21b). The precipitate is washed by distillation of the solvent from the lower receiver into the upper portion of the apparatus (with the stopcock in the sidearm open) and repetition... 

Fig. 9.21 Vacuum line filtration apparatus, (a) A solution ready to be filtered (b) apparatus inverted and bottom receiver cooled to bring about suction filtration. The precipitate is washed by opening the stopcock, allowing the bottom tube to warm, and cooling the top with glass wool dipped in liquid nitrogen. The components are held together by springs or rubber bands. A grease-free version of similar dimensions may be constructed by making the following substitions T 24/40 stopcock - valve 4 14/35 - i/j-in. Cajon O-joint.

Fig. 1.25. Low-temperature filtration apparatus. This is utilized the same way as the fritte pictured in Fig. 1.206. The outer jacket is filled with a Dry Ice/acetone solution when filtering heat-sensitive compounds, liquid ammonia solutions, etc. (Reproduced by permission of the copyright owner, The American Chemical Society, from J. E. Ellis, K. L. Fjare, andT. G. Hayes, J. Am. Chem. Soc. 103, 6100(1981).)...

A convenient filtration apparatus for this purpose may be constructed by cutting the bottom off a bottle and then inserting a Buchner funnel through a stopper in the mouth of the bottle. The space between the bottle and the funnel is then packed with Dry Ice. 

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