Filtration glass fiber

Suspended Solids. Suspended soflds are determined by filtering a known volume of water through a glass-fiber filter and weighing the filter before and after filtration. The filter is dried at 105—110°C, and the weight difference is equal to the suspended soflds. 

Experimentally measured dielectrophoretic augmentation factor DAF as a function of air speed and applied voltage for a glass-fiber filter (HP-100, Farr Co.). Cf Fielding, Thompson, Bogardus, and Clark, Dielectrophoretic Filtration of Solid and Liquid Aerosol Particulates, Prepr. 75-32.2, 68th ann. meet.. Air Pollut. Control Assoc., Boston, June 1975. 

Weigh 2.5 or 5 g of crop matrix into a blending vessel. Fortify samples at this point with the appropriate analytical standards. Allow the solvent to evaporate. Add 100 mL of acetone-water (4 1, v/v) and blend the mixture using an Omni mixer equipped with a macro generator for 5 min at 6000-7000 rpm. Filter the sample through a Whatman 934 AFI glass-fiber filter paper on a Buchner funnel/vacuum flask setup. Rinse the blending cup and filter cake with 100 mL of acetone. Transfer the filtrate into a 200-mL TurboVap vessel. 

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. 

The choice of the filter medium is often the most important consideration to ensure efficient operation of a filter. Its function is generally to act as a support for the filter cake, while the initial layers of cake provide the actual filter. The filter medium should be selected primarily on the basis of its ability to retain solids without binding. It should be mechanically strong and corrosion resistant, and should offer as little resistance as possible to the flow of the filtrate. The media are made from widely different materials such as cotton, wool, linen, nylon, jute, silk, glass fiber, porous carbon, metals, rayon and other synthetics, and miscellaneous materials like porous rubber. Cotton fabrics are most commonly used because they are available in a wide variety of weaves, and are cheap. 

At this point 20-30 g. of short glass fiber or asbestos is added and the yeast is filtered out by suction. The filtrate is concentrated to a thick syrup under diminished pressure on a water bath, care being taken to keep the temperature below 40° (Note 3). The residue (about 200 cc.) is taken up in a mixture of 400 cc. of absolute alcohol and 100 cc. of dry ether (Note 4). The precipitate formed is removed by centrifuging, the supernatant liquid is decanted, and the residue is extracted with a mixture of 200 cc. of 98.5 per cent alcohol and 100 cc. of dry... 

Remove the insoluble dicyclohexyl urea (DCU) by-product by filtration using a glass fiber filter pad and vacuum. 

At 20 °C 390 to 400 mg/L after filtering with glass fibers 380 mg/L after membrane filtration (modified shake flask method-fluorometry, Hashimoto et al., 1982)... 

It had been shown that 50 mM Tris-citrate buffer with 1 M NaCl was a suitable incubation buffer for the binding to GATl [95], The high salt concentration in this incubation buffer caused no problems in the new MS binding assays, since most of the incubation buffer was removed before the liberation step. The separation of the bound from the nonbound marker was conducted by filtration over glass fiber filters as common in radioligand binding assays. 

Asbestos fibers are found worldwide in many products as reinforcement in cement water pipes and the inert and durable mesh material used in filtration processes of chemicals and petroleum, for example. However, asbestos is not the only inorganic fiber in use today. Synthetic inorganic fibers abound. Glass fibers have replaced copper wire in some intercontinental telephone cables. Fiberglas (a trade name) has become the insulation material of choice in construction. Carbon and graphite fiber composites are favored materials for tennis racket frames and golf clubs. Fibrous inorganic materials have become commonplace in our everyday lives. 

In the meantime, mount the glass fiber filters on top of the filter sheet in the dot-blot filtration unit (Schleicher and Schuell). For duplicate determinations, two samples each of 45 pi solution are spotted on separate filters. 

The key to these assays is to find a suitable method by which the bound labeled ligand can be measured, separate from the unbound fraction. Three separate methods have been used to measure hERG binding filtration through glass fiber filters [36, 37], scintillation proximity assay (SPA) technology [38] and fluorescence... 

Complete precipitation by PEG needs 30 min to 15 h at 0 ° C. The precipitate is collected by centrifugation or filtration on glass fiber filters (e.g., Whatman GF/A). Dissolve the precipitate in ddHaO and dialyze against an appropriate buffer. An increase in volume occurs during dialysis. 

Filter flow rate was compared between 42-mm diameter, 0.45-/zm Selas Ag filters and 0.86-cm X 5.78-cm, 0.3-/zm Balston glass-fiber filter tubes, grade AA. Samples were pumped at a constant pressure of 30 psi of N2 gas through each filter filtrate was collected as a function of time. 

Figure 3. Variation of flow rate with filtration time for silver membrane and glass-fiber filters at 30 psi for Ogeechee River water. (Reproduced with permission from reference 11. Copyright 1985 John Wiley.)...

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