Ultrasound-Assisted Nebulization

Ultrasound assisted aerosol formation or nebulization prior to sample insertion into an atomic detector is dealt with in Chapter 8 on the grounds of its close relationship to the instrument in spatial and temporal terms. Also, as a step of spray drying, known as atomization , is discussed in Chapter 2 inasmuch it can be used for sample conservation purposes and hence as an analytical operation preceding sample preparation. This section is concerned with other non-analytical uses of US-assisted aerosol formation that are closely related to the analytical field and can open new avenues for the development of previously unexplored analytical uses. 

Ultrasound-assisted nebulization is largely used in the clinical field, where the word aerosolization or aerosoling is used preferentially over nebulization , and industrial field, where US-assisted nebulization and US-assisted spraying are preferred. 

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Finally, Chapter 8 disousses some well-established detection techniques such as electroanalysis, whioh has been greatly improved by US assistance and led to the development of sonoeleotroanalysis, and others in which ultrasound has provided a more efficient way of placing or transporting the sample — or the solution resulting from a given treatment — to the deteotion point (e.g. ultrasound-assisted levitation or nebulization). 

Ultrasonic nebulization is known to provide a higher analyte transport efficiency than pneumatic nebulization (normally 8-15 times higher) this results in improved sensitivity and lower detection limits, which is especially important for the analysis of species at trace or ultratrace levels [31-35]. Ultrasound-assisted generation of smaller drops and the use of a desolvation system to remove most of the solvent load allow the production of fine, dry analyte-enriched aerosol for insertion into a detection system some authors, however, ascribe most of the sensitivity increase of USNs to the desoivation system aione [36]. 

Ultrasounds have been used to assist in the insertion of samples into solid-liquid analytical systems for some time. The earliest ultrasonic nebulizers and automatic slurry sampling systems were reported in the 1980s. However, the actual potential of ultrasounds for increasing the efficiency of sampling systems remains to be explored. Thus, a recently developed technique based on acoustic levitation has been found to substantially... 

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