Effervescence-Assisted Microextraction: One Decade of Developments
A decade ago, our research group introduced the concept of effervescence-assisted microextraction. The first approach of this alternative consisted of a micrometric sorbent (OASIS-HLB) compressed in a tablet along with a carbon dioxide source (sodium carbonate) and a proton donor (sodium dihydrogen phosphate) [1] . The tablet is then placed on a syringe, and an aqueous sample is drawn. Once the sample enters in contact with the tablet, an effervescent reaction occurs, and the sorbent is efficiently dispersed by the CO 2 bubbles formed. Later, the technique was challenged with a difficult-to-disperse nanometric sorbent, unmodified multi-walled carbon nanotubes (MWCNTs) [2] . In this second adaptation, the nanotubes are compressed along with the effervescence precursors in a tablet format, and as occurs with many pharmaceutical applications, dropped in a glass containing a large aqueous sample volume (100 mL) and effervescent reaction takes place. The in-situ generated gas can dispers