Mechanical shaking

The mechanical shaking machine is employed for auto matic mixing of heterogeneous systems and finds many applications in the organic chemistry laboratory. 

By treatment with anhydrous aluminium chloride (Holmes and Beeman, 1934). Ordinary commercial, water-white benzene contains about 0 05 per cent, of thiophene. It is first dried with anhydrous calcium chloride. One litre of the dry crude benzene is shaken vigorously (preferably in a mechanical shaking machine) with 12 g. of anhydrous aluminium chloride for half an hour the temperature should preferably be 25-35°. The benzene is then decanted from the red liquid formed, washed with 10 per cent, sodium hydroxide solution (to remove soluble sulphur compounds), then with water, and finally dried over anhydrous calcium chloride. It is then distilled and the fraction, b.p. 79-5-80-5°, is collected. The latter is again vigorously shaken with 24 g. of anhydrous aluminium chloride for 30 minutes, decanted from the red liquid, washed with 10 per cent, sodium hydroxide solution, water, dried, and distilled. The resulting benzene is free from thiophene. 

Figure 13.17 shows isometrics of mechanical shaking, reverse air, cartridge, and pulse-jet types of bag filter units. 

Figure 4-65. Bag filtration with mechanical shaking for bag cleaning. Courtesy of Dracco Div. Fuller Co.

Intermittent filters are best suited to small applications which will allow the process to be stopped at intervals. The interval used is 4h (i.e. a morning or afternoon shift). Mechanical shaking is done by either hand or electric motor. The application of these filters is limited to the incoming dust burden of the order of 5 g/m and is known as nuisance dust. 

Residual dinitroaniline herbicides are generally extracted from 10-25 g of air-dried soil samples using organic solvents such as ethyl acetate, acetonitrile, methylene chloride and acetone by sonication, mechanical shaking or Soxhlet extraction. If necessary, the extract is then cleaned by a Florisil column or SPE. The extract is allowed to evaporate completely to dryness and the residue is dissolved in an appropriate volume of the solvent for GC or HPLC analysis. 

A soil sample (10 g) was extracted by mechanically shaking with methanol-deionized water. This mixture was filtered and a portion was removed for partitioning into toluene-hexane. A phenyl solid-phase extraction (SPE) cartridge was employed... 

In another spectrophotometric procedure Motomizu [224] adds to the sample (2 litres) 40% (w/v) sodium citrate dihydrate solution (10 ml) and a 0.2% solution of 2-ethylamino-5-nitrosophenol in 0.01 M hydrochloric acid (20 ml). After 30 min, add 10% aqueous EDTA (10 ml) and 1,2-dichloroethane (20 ml), mechanically shake the mixture for 10 minutes, separate the organic phase and wash it successively with hydrochloric acid (1 2) (3 x 5 ml), potassium hydroxide (5 ml), and hydrochloric acid (1 2) (5 ml). Filter, and measure the extinction at 462 nm in a 50 mm cell. Determine the reagent blank by adding EDTA solution before the citrate solution. The sample is either set aside for about 1 day before analysis (the organic extract should then be centrifuged), or preferably it is passed through a 0.45 xm membrane-filter. The optimum pH range for samples is 5.5 - 7.5. From 0.07 to 0.12 p,g/l of cobalt was determined there is no interference from species commonly present in seawater. 

Schwab AP, Su J, Wetzel JSS, Pekarek S, Banks MK. Extraction of petroleum hydrocarbons from soil by mechanical shaking. Environ. Sci. Technol. 1999 33 1940-1945. 

Note (1) e.g., by mechanical shaking or sonication the solution with CHCI3. 

Triboluminescence Mechanical shaking, rubbing or crushing Crack detection in composite materials... 

The solution of the magnesium complex, which is difficult to decompose, is facilitated by mechanical shaking of the mixture for 30 minutes. 

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