Glass plate carriers

Slurry overlay on various carriers (glass plate, aluminium or polymer foil) and coatings... 

To prepare the funnel G, fit it to the filter-flask and wash it by passing distilled water, ethanol and acetone through the glass plate H. Remove G from the bung J, wipe it with a clean cloth, and dry it in an oven for 15 minutes at 140°. Then carefully wipe it again with the cloth, and place it in the balance case on the carrier D (Fig. 90) for 15 minutes to attain an equilibrium with the air. Then transfer it to the balance pan and weigh. 

Tape can be cast on a stainless steel table or belt, glass plate, or a Mylar, Teflon, or ceUulose acetate film carrier. The tape should adhere to the carrier sufficiently to prevent curling, but should be easily removable. In a continuous casting process, the tape is dried by air flowing 1—2 m/min counter to the casting direction. A typical dry green tape contains approximately 35 vol % organics, 50% ceramic powder, and 15% porosity. 

Electrophoretic separation of dendrimers is usually performed with polyacrylamide gel applied to glass plates of carrier films (flat bed, slab gel electrophor-... 

In conjunction with their studies of evaporated barium gettei film, Oda and Tanaka (97) investigated the relationships between the structuie of a nickel film evaporated on a glass plate and the conditions of its preparation. These, nickel films had a remarkable tendency to expose the (110) plane with increasing thickness even if made in a high vacuum. When the support on which the nickel vapor was condensed rvas heated, various kinds of crystal planes were observed to develop parallel to the support as a function of the temperature, e.g., the (110) plane at 100°C., the (110) plane and (200) plane at 200°C., and the (200) plane at 300°C. A non-oriented surface was formed at 350°C. From this, it seems reasonable to conclude, that even ordinary metallic catalysts, including carrier-supported catalysts, may preferentially expose crystal planes of various kinds, depending on their mode of preparation. 

Locate a plate carrier and a metal box with several glass plates in it. Put two glass plates in it. 

Fig. 25. Devices for continuous development. A angled trough containing adsorbent B two-part special cover through which the plate projects. 1 carrier plate 2 layer S adsorbent for drawing up the solvent 4 angled trough 5 glass plate 6 glass or metal plate with suitable slots...

Coupling with preparative GC can likewise be carried out with success, best with preparative TLC (see p. 97). The yield, which is only moderate, is a drawback here. Adequately deep penetration of a thicker layer is achieved when the carrier plate is relatively thin and is cooled from below with a cprrent of cold gas (over 60 1/h nitrogen, passed through acetone/solid COg or liquid nitrogen). Thin aluminium plates should be better than glass plates in such cases. 

Apphcations of activation analysis in TLC are not so far known. The multitude of elements in adsorbent, binder and glass plate would demand an extensive modification of the chromatographic procedure in order to prevent formation of long lived, active isotopes in the carrier material. The advantages of TLC, like high layer capacity and speed would be virtually forfeited in relation to the high sensitivity of the measuring process and the appreciable expense associated with the activation. 

After development, the layer is freed from solvent and sprayed with water until it is transparent. A still moist strip of filter paper, freshly impregnated with a hydroxylamine reagent, is then pressed on to the layer with a glass plate. The impregnation solution is 100 ml of a mixture of equal parts of 7% aqueous hydroxylamine hydrochloride solution and 32% potassium hydroxide in methanol. The carrier plate is placed on a hot plate at 35—45° C. The esters evaporate and are converted in the paper to potassium hydroxamates. After 15— 30 min, these can be visualised as red zones by spraying with a 5% solution of ferric chloride in 0.5 N hydrochloric acid. 

The chromatogram is sprayed with I and then with II. A 5 mm margin is scraped from both sides of the plate. Two polyethylene strips of suitable breadth are laid on the margins so that a second glass plate can be placed on the layer. After heating 1 h at 40° C in the dark, the carrier plate is cooled and laid in an ether bath for 10 min. The layer is then dried briefly and the spots outlined. 

Thin-layer chromatography today is a dynamically developing modem analytic method. Areas of progress include increase of the spectrum of selectivity, improvement of efficiency, and in certain cases simplification of handling. The discussion of bulk sorbents and precoated layers above is not a complete enumeration of all possibilities e.g., the different carriers for the layers (glass plates, aluminum, or plastic sheets) are not shown explicitly. In addition, special plates with very restricted applicability are not discussed. 

Figure 12.19 Design of a drapeability tester (1) glass plate, (2) frame, (3) cover, (4) base plate, (5) specimen, (6) carrier ring, (7) light source, and (8) concave mirror (Reumann, 2000)...

FIG. 17 Schematic illustration of the setup for a tip-dip experiment. First glycerol dialkyl nonitol tetraether lipid (GDNT) monolayers are compressed to the desired surface pressure (measured by a Wilhehny plate system). Subsequently a small patch of the monolayer is clamped by a glass micropipette and the S-layer protein is recrystallized. The lower picture shows the S-layer/GDNT membrane on the tip of the glass micropipette in more detail. The basic circuit for measurement of the electric features of the membrane and the current mediated by a hypothetical ion carrier is shown in the upper part of the schematic drawing. 

Preparation of such plates requires care and practice, and whereas they were once popular, they have now been replaced by commercial plates for most, if not all, applications. The quality of the commercial plates is good, and they have the added advantage of tolerating handling, which is often a problem in the case of homemade plates in which the layers are readily damaged. The phases are attached to the surface of the carrier material, glass, plastic, or metal by means of binders that do not affect separation but stabilize the mechanical properties of the layers in commercial plates. 

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