Homogeneous Immersion

Add 101 g. (55 ml.) of concentrated sulphuric acid cautiously to 75 ml. of water contained in a 1 htre beaker, and introduce 35 g. of finely-powdered wi-nitroaniline (Section IV,44). Add 100-150 g. of finely-crushed ice and stir until the m-nitroaniUne has been converted into the sulphate and a homogeneous paste results. Cool to 0-5° by immersion of the beaker in a freezing mixture, stir mechanically, and add a cold solution of 18 g. of sodium nitrite in 40 ml. of water over a period of 10 minutes until a permanent colour is immediately given to potassium iodide - starch paper do not allow the temperature to rise above 5-7° during the diazotisation. Continue the stirring for 5-10 minutes and allow to stand for 5 minutes some m-nitrophenjddiazonium sulphate may separate. Decant the supernatant Uquid from the solid as far as possible. 

Hydrolysis of benzyl cyanide to phenylacetamide. In a 1500 ml. three-necked flask, provided with a thermometer, reflux condenser and efficient mechanical stirrer, place 100 g. (98 ml.) of benzyl]cyanide and 400 ml. of concentrated hydrochloric acid. Immerse the flask in a water bath at 40°. and stir the mixture vigorously the benzyl cyanide passes into solution within 20-40 minutes and the temperature of the reaction mixture rises to about 50°, Continue the stirring for an additional 20-30 minutes after the mixture is homogeneous. Replace the warm water in the bath by tap water at 15°, replace the thermometer by a dropping funnel charged with 400 ml. of cold distilled water, and add the latter with stirring crystals commence to separate after about 50-75 ml. have been introduced. When all the water has been run in, cool the mixture externally with ice water for 30 minutes (1), and collect the crude phenylacetamide by filtration at the pump. Remove traces of phenylacetic acid by stirring the wet sohd for about 30 minutes with two 50 ml. portions of cold water dry the crystals at 50-80°. The yield of phenylacetamide, m.p. 154-155°, is 95 g. RecrystaUisation from benzene or rectified spirit raises the m.p. to 156°. 

As the vessel is only about half filled with slurry, the disks become coated with the cake when immersed, the cake is dewatered when the disks emerge from the slurry, and scraped or blown off, by reverse blow, into the central conveyor which takes the cake to one end of the vessel. The planetary action and the slow movement of the disks through the feed slurry ensure exceptionally good homogeneity of the cake which is critically important for good dewatering characteristics the typical speed of rotation of the planetary system of shafts is from 0.8 to 1 rpm. 

Agitate the slurry by hand or with a wide spatula to maintain a homogeneous suspension. Immerse the test leaf face downward to approximately one-half the depth of the slurry. 

The well-dried chromatogram (1 h at 105°C if acidic or basic eluents have been employed) is immersed in the dipping solution for 1 s or homogeneously sprayed with the spray solution and then dried in a stream of cold air. Acids yield blue zones on a colorless or pale blue background [1] which gradually darkens. 

The chromatogram is freed from mobile phase and immersed in the dipping solution for 3 s or the solution is sprayed on homogeneously the chromatogram is then heated to 90 —140°C for 5 —10 min. Brown zones are produced on a beige-grey background. 

The chromatogram is freed from mobile phase in the drying cupboard (10 min, 120°C) and immersed for 1 s in the reagent solution or sprayed homogeneously with it until the plate starts to appear transparent it is then dried briefly in a stream of warm air and heated to 125 —130 °C for 45 min. 

The developed chromatogram is freed from mobile phase by heating to 110°C for 10 min in the drying cupboard. It is allowed to cool and immersed for 1 s in or sprayed homogeneously with the reagent the plate is then examined (while still moist). 

The chromatograms are freed from mobile phase, immersed in the reagent solution for 1 s or sprayed homogeneously with it and then dried in a stream of cold air. 

The chromatogram is freed from mobile phase in a stream of warm air and either immersed for 2 s in the dipping solution or homogeneously sprayed with it until the layer begins to be transparent. In the case of detergents the chromatograms are evaluated while still moist [3], in the case of sweeteners after drying for 10 min in the dark [10]. 

The anode tends to give rise to a high resistance polarisation due to the formation of a voluminous corrosion product, particularly when buried as opposed to immersed. This can be alleviated by closely surrounding the scrap with carbonaceous backfill this of course increases the cost if the backfill is not also a local by-product. It is necessary under conditions of burial to ensure compactness and homogeneity of backfill (earth or carbon) at all areas on the steel, otherwise particularly rapid loss of metal at the better compacted areas could lead to decimation of the groundbed capacity. 

Extraction Frozen krill (85 g) is briefly homogenized with 60% ethanol (220 ml) at about 0°C, and centrifuged. The supernatant is rapidly concentrated under reduced pressure in a 2-liter flask at about 40°C (using a rotary evaporator, a mechanical vacuum pump, and a large condensate trap immersed in dry ice/acetone) to a volume of 15-20 ml. After the addition of 30 ml of cold ethanol, the solution is temporarily stored at —30°C. Materials similarly prepared from 6 batches (510 g krill in total) are combined, centrifuged, and the supernatant is concentrated to 30 ml, and then mixed with 70 ml of ethanol. Compound F in the solution is extracted with 120 ml of n-butanol. 

Steroids The developed chromatograms are freed from mobile phase in a stream of cold air, then either immersed for 2 s in dipping solution I and, after brief intermediate drying in a stream of warm air, immersed in dipping solution II for 2 s or homogeneously sprayed with spray solution III and, after being left for 5 min at room temperature, heated at 110°C for 5 min and evaluated. 

The chromatograms are freed from mobile phase in a stream of warm air, then immersed in the dipping solution for 2 s or homogeneously sprayed with the appropriate spray solution. Then, in the case of N-ethyl derivatives, the plate is heated to 105-110 °C for 2 min to accelerate the reaction [7]. Heating (e. g. to 80-105 °C for 15 min) can also lead to color intensification and color change in the case of other alkaloids [5, 6]. 

The chromatograms are freed from mobile phase (15 min 100 °C), placed in the empty chamber of a twin-trough chamber containing 20 ml solution I (chlorine chamber) for 1 min or homogeneously sprayed with solution I until the layer begins to be transparent. They are then freed from excess chlorine in a stream of warm air for 30 min and immersed in the dipping solution for 3 s or sprayed homogeneously with it. 

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