Developments in ultrasound-assisted microextraction techniques for isolation and preconcentration of organic analytes from aqueous samples

• Ultrasound assistance is the future trend in “green” miniaturized extraction.
• Faster, more efficient extraction uses ultrasound assistance.
• Versatile applications of ultrasonic assistance to extraction of organic analytes.

The great potential of ultrasonic assistance in sample preparation, especially extraction, is being recognized. In this review, we discuss the applications of ultrasonic radiation in assisting microextraction. Topics covered include ultrasound-assisted emulsification microextraction, ultrasound-assisted-emulsification-dispersive liquid-liquid microextraction, and ultrasound-assisted hollow-fiber liquid-phase microextraction with its modifications. We critically discuss the advantages and the limitations of each technique. Finally, we summarize recent practical applications.