Analytical Microextraction Techniques

Current overview and perspectives in environmentally friendly microextractions of carbamates and dithiocarbamates

“…Some properties of the solvents are responsible for the analyte transport between immiscible phases, such as vapor pressure, solubility, molecular weight, acid dissociation, and hydrophobicity. Furthermore, recent researches had developed new materials and solvents to improve the extraction efficiency of carbamates and dithiocarbamates (Abdel-Rehim, 2004;Valcárcel et al, 2017;Jalili et al, 2019Jalili et al, , 2020bMaciel et al, 2019;Ramos, 2020a;Venson et al, 2019).…”

“…The SPME is based on the partition of the analytes between the sample and a solid phase, which is supported on a fused silica fiber. The MEs and their use in the determination of carbamates and dithiocarbamates are described in detail in the next sections, as well as the last advances of those techniques (Valcárcel et al, 2017;da Silva Sousa et al, 2021;Ouyang & Jiang, 2016;Pinto et al, 2010;Ramos, 2020b).…”

“…Also, the temperature can modify the efficiency of mass transferences, hence, its evaluation is an important parameter. Extraction time can be reduced by the use of electromembrane extraction, in which the analytes are extracted by an electrokinetic migration (Chen et al, 2019;Gjelstad & Rasmussen, 2012;Khan et al, 2020;Valcárcel et al, 2017).…”

“…These MEs present easy operation, high efficiency on the preconcentration, and separation of target carbamates and dithiocarbamates, and they can be automated. Furthermore, new sorbent materials have been developed for the extraction of target analytes with different chemical properties, since the properties of the commercially available fibers are limited (Valcárcel et al, 2017;Balasubramanian & Panigrahi, 2011;Kataoka, 2021;Llompart et al, 2019;Ouyang & Jiang, 2016;Pawliszyn, 2012b).…”

“…Direct SPME is based on the insertion of the extraction fiber into a solution containing the sample. The target compounds are direct extracted from the sample to the extraction fiber, as presented in Figure 4a times, due to alteration of the diffusion coefficient, and consequently, modifying the mass transference (Valcárcel et al, 2017;Ouyang & Jiang, 2016;Pawliszyn, 2012a;Zhang et al, 2018). The mass transference is directly influenced by the boundary layer, due to the relation of the thickness of the sorbent phase with the rate of diffusion and convection of the target compounds from sample solution to extracting phase.…”