Small filter apparatus

Small filter apparatus (VDI 3875, Part 1,1996) This device includes the sampling unit, a rotary pump with an output of 2.6m /h to 2.8m /h, a separator for the abraded carbon of the rotary pump, a plate anemometer and a timer. 

PCDDs/PCDFs LIB filter apparatus Small filter apparatus glass fiber filter/PUF GC/MS A... 

PAHs Small filter apparatus High volume pump glass fiber filter glass fiber filter/XAD-2 GC/FID GC/MS B C,D... 

Glass fiber filter (VDI 3498, Part 1,1998) External diameter 120 mm (LIB apparatus) or 50 mm (small filter apparatus) with a collection efficiency of 99.8 % for particles with an aerodynamic diameter >0.3 //m. The filter must be baked-out at 250-400 °C before use. 

For the measurement of PCBs in indoor air, the VDI guideline 2464, Part 1 (1992) is currently in preparation. Sampling can be performed on a glass fiber filter and on PUF plugs by use of the LIB filtering apparatus or a small filter apparatus. Before sampling... 

When the amounts of evolved gas are likely to be small, the apparatus of Fig. 11.31 may be used all the evolved gas may be swept through the reagent by a stream of air introduced by a rubber bulb of about 100 ml capacity. The approximate dimensions of the essential part of the apparatus are given in a, whilst the complete assembly is depicted in b. The sample under test is placed in B, the test reagent is introduced into the filter tube A over a tightly-packed... 

Since most probably the extract (binder solution) contains a small amount of fine mineral filler (certainly when the filler content in the initial test portion is more than 3%), the total quantity of extract collected is centrifuged further using the continuous-flow (filterless) binder extractor shown in Figure 9.3 (Controls Sri 2014) or a pressure filter apparatus. 

Filtration of the samples can be done with any of the pressure or vacuum systems in common use (see Chapter 2). The filtering apparatus should be cleaned thoroughly by acid washing (see Section 12.1.4). Membrane filters release no detectable arsenic species, but should be rinsed by passing a small amount of the sample through them. Glass fibre filters may contain soluble arsenate or arsenite and should not be used. In general, filtration is not required, because oceanic particulates contain few soluble arsenic species that would be detectable with this method. 

The precipitated polyethylene from the above extraction is pushed aside with a microspatula. The porous metal filter portion of the filter apparatus is inserted into the solution and about 5-10 ml of solution is drawn into the syringe. The Teflon tube is removed from the ferrule on the needle and the filtered solution is dispensed into a small... 

Place a tared filter on the base-plate of a membrane-filter apparatus with a small slip of aluminum foil under the margin of the disc to facilitate its removal when wet Assemble the filter funnel and filter a suitable volume of sample (Note /) through the membrane using the controlled pressure device to limit suction to 15 inches of mercury (Note g). 

For the filtration of very small quantities of crystals, the simple apparatus shown in Fig. 46 is often used. It consists of a fine glass rod (sometimes termed a filtration nail ) which is flattened at one end, the flattened surface being preferably roughened. It fits as shown into a small funnel which replaces F (Fig. 45). A circular piece of filter-paper is cut e-g.y with a clean sharp cork-borer) so as to fit completely and snugly over the flat end. After draining, the nail is raised and the filter-paper and crystals are removed with forceps and dried. 

Now filter the ether through a fluted filter-paper directly into a 100 ml. distilling-flask, and then equip the latter with a 100° thermometer and a double-surface condenser to the end of the latter attach a receiver with a rubber delivery-tube precisely as before. Place the flask cautiously in a water-bath, the contents of which have previously been heated to about 60° at some distance from the apparatus arrange the depth of the flask in the water-bath so that the ether distils slowly over. Collect the fraction boiling between 34-39°. Yield, 25 g. (35 ml.). Not more than a verv small residue of etlianol should remain in the flask. 

Filter the dried ethereal solution, and then distil off the ether from a small flask, using precisely similar apparatus and the same method as those described in the preparation of aniline (Fig. 64, p. 163 see also Fig. 23(E), p. 45) and observing the same precautions. When the ether has been removed, fit the distilling-flask to a short air-condenser, and distil the benzonitrile, collecting the fraction boiling between 187" and 191°. Yield, 16-5 g. (16 ml.). 

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