Characterization of the effects involved in ultrasound-assisted extraction of trace elements from artichoke leaves and soybean seeds.

Ultrasonication is known to induce cavitation and can thus accelerate extraction, dissolution, digestion, and other processes, while the intense mixing caused by the propagation of ultrasound waves enhances analyte transfer to the extraction medium. Consequently, ultrasound-assisted extraction (UAE) is viewed as a simple procedure well suited for the extraction and subsequent determination of trace elements in food. Herein, we use different techniques to characterize several processes involved in probe- and bath-based UAE, apply them to the determination of trace metals (Cd, Cu, Ni, Pb, and Zn) in globe artichoke leaves and soybean seeds, and closely monitor the extraction rates of selected analytes. The developed UAE-based method is found to comply with the criteria of Green Chemistry and is concluded to be a reliable, simple, and cheap alternative to standard food analysis techniques.