Selective electromembrane extraction based on isoelectric point: Fundamental studies with angiotensin II antipeptide as model analyte

Recent developments in capillary and microchip electroseparations of peptides (2015–mid 2017)

“…. Special reviews and papers deal with the particular sample clean‐up techniques, such as SPE , solid‐phase microextraction (SPME) , electromembrane extraction , selective electromembrane extraction based on isoelectric point , magneto‐immuno capture , and on‐line electrodriven sample‐stacking techniques . The latter electrodriven procedures include field amplified sample stacking , field enhanced or field‐amplified sample injection (FESI or FASI) ; large volume sample stacking (LVSS) , transient‐ITP (t‐ITP) , multiple capillary ITP (CITP) with repetitive hydrodynamic injection , dynamic pH junction , electrokinetic supercharging , and sweeping .…”

“…Sample concentration is frequently implemented also by combined electro‐chromatographic or pure electrophoretic approaches . The examples of the former group are (i) capillary liquid–liquid electroextraction based on a fast electromigration of polar analytes from organic phase to aqueous phase and on formation of a narrow zone in this phase and (ii) electro‐driven extraction of angiotensin II antipeptide across supported liquid membrane . Both these approaches can be used for a fast preconcentration of peptides prior to their CE and LC analyses .…”

Quantification of controlled release leuprolide and triptorelin in rabbit plasma using electromembrane extraction coupled with HPLC–UV

“…pH value of the donor phase determines the charge density of the peptide and DEHP at the SLM interfaces . The results obtained from BBD–RSM analysis for two peptides showed that maximum recoveries would be obtained when pH of the donor phases are adjusted at about 4.5.…”

Electromembrane extraction of polar basic drugs from plasma with pure bis(2-ethylhexyl) phosphite as supported liquid membrane

“…After this initial phase, the system-current normally decrease and is stabilized at a certain level determined by (1) ions from the sample. In order to achieve a stable EME system, the system-current should normally not exceed 50 µA [37][38][39]. Above this level, bubbles on both electrodes are often observed due to excessive electrolysis in the sample and acceptor solution according to the following equations when the EME system is tuned for basic (cationic) analytes:…”

“…The EME procedure and the preparation of Accurel polypropylene PP 1E (R/P) flat membrane-based EME device have been described elsewhere [37][38][39]. Ten µL of the SLM was used for each extraction.…”