Sample treatments based on dispersive (micro)extraction

Abstract

Sample treatment has evolved in the last few years following basic trends, simplification, automation and miniaturization being the most remarkable ones. Microextraction techniques, including solid phase microextraction (SPME) and liquid phase microextraction (LPME), have emerged in this context showing very competitive features if they are compared with their classic counterparts. Essentially, extraction techniques are surface dependent processes since their kinetics depend directly on the contact surface between the sample and the extractant phase. This aspect, which is important in any extraction procedure, becomes critical when the amount of extractant is reduced to the microscale. In this context, dispersive-based procedures have gained importance as rapid and efficient sample treatment methodologies. This review article deals with the use of dispersion in micro-solid phase extraction (m-SPE) and LPME. The main techniques as well as their powerful combinations will be described in depth with references to the most relevant applications.

Dispersive micro solid-phase extraction using multiwalled carbon nanotubes combined with portable total-reflection X-ray fluorescence spectrometry for the determination of trace amounts of Pb and Cd in water samples

“…In this context, dispersive-based procedures have gained importance as rapid and efficient sample treatment methodologies. 6 In dispersive solid phase extraction (DSPE) and in dispersive micro solid-phase extraction (DMSPE) the solid sorbent in the mg or mg range is dispersed in the analyzed solution. Such a strategy promotes the immediate interaction between the analytes and sorbent and shortens the time of sample preparation.…”

Double salts of ionic-liquid-based surfactants in microextraction: application of their mixed hemimicelles as novel sorbents in magnetic-assisted micro-dispersive solid-phase extraction for the determination of phenols

“…In its dispersive mode (μ-dSPE), the sorbent material is dispersed into the sample matrix with the aid of vortex, ultrasound, or strong stirring. This dispersion accelerates the mass transfer of analytes, providing higher extraction efficiencies and lower extraction times than nondispersive μ-SPE [8].…”

Extraction and stirring integrated techniques: examples and recent advances

“…Different variables, for example extraction temperature, use of secondary reactions, selection of the appropriate pH, among others, may be varied to increase this potential transfer. Kinetic properties, on the other hand, determine the rate at which equilibrium is reached [2]. With regard to the kinetics, the contact surface between the sample and the extracting phase, and stirring of the solution may be emphasized.…”