Sonic disruptor

The paper [13] describes the use of a Tekmar sonic disruptor (250 W, 20 KHz) equipped with a standard horn with tapped end, with the trimer switch on hold and the output control set at 5. 

The mixing for W/O emulsions is usually performed in the laboratory by simple equipment like a magnetic stirrer, an ordinary mechanical stirrer with multiple fins, a planetary stirrer, a high shear / high speed blender, an ultrasonic vibrator or in some cases a sonic disruptor [18]. Ordinary rotational mixing can be coupled with sonication for obtaining relatively small droplets [42]. 

Review.1 This review includes a discussion of the three types of ultrasonic generators whistlers, cleaning baths, and probe disruptors. The last is the most efficient, but the most expensive. Cleaning baths are inexpensive, but are limited in the temperature range to that of the liquid used, generally water. The review concludes that sonication is most useful in heterogeneous reactions, particularly those of organometallics. The references (235) date from 1953 to the present time, with most in the last 10 years. 

An alternative extraction technique is sonication of the soil with an ultrasonic probe. The technique is relatively quick, but its speed is limited by the sequential nature of sample processing. Samples are placed in a glass extraction vessel and mixed with a drying agent (anhydrous sodium sulphate) until free flowing. Solvent is added and the ultrasonic disruptor is placed in the solvent and above the sample for a period of 3 min. The solvent is decanted, fresh solvent is added to the sample, and the process is repeated twice more. The extracts are combined and concentrated for further processing (cleanup). 

RiZn. Dialkylzinc reagents can be prepared from an organic halide, lithium wire, and zinc bromide at 0° in toluene-THF by sonication in a cell-disruptor generator. Yields are essentially quantitative. Diarylzinc reagents and dimethylzinc can be prepared by sonication in an ultrasonic laboratory cleaner. 

Figure 10-3. Sonicator or sonic cell disruptor showing the sonic wave generator in the background and the titanium transducing element in the foreground. Needle tips capable of operating in small test tubes may be interchanged with the larger tip (arrow) shown here. (Courtesy of Heat Systems-Ultrasonics, Inc., Plainview, N.Y.)...

This problem was overcome by use of a cell-disruptor type ultrasound generator. This modification permitted much greater control of the sonication conditions and allowed addition of 1°, 2°, 3° alkyl and allylic groups in essentially quantitative yield within 10-20 min [144] (Scheme 63). 

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