How is polyacrylamide made?

Polyacrylamide is a synthetic membrane created by the polymerization of acrylamide monomers with N,N-methylenebisacrylamide as cross-linker via a free-radical initiated vinyl polymerization mechanism. The pores (radius 20–140 nm) in the gel structure are highly reproducible, and are controlled by the ratio of acrylamide and bisacrylamide.

What is gel electro-membrane extraction (G-EME)?

Conclusions and outlooks Gel electro-membrane extraction (G-EME) has been developed during the last couple of years into a promising tool for sample preparation. G-EME is based on electrokinetic transfer of target analyte from an aqueous sample, through a bio-polymeric gel membrane, and into acceptor.

Which biopolymer membranes are used for polar analytes?

Biopolymer membranes used include agarose, agar, tragacanth, polyacrylamide, and chitosan. G-EME is completely solvent-free (except two-phase G-EME mode), and represents a highly interesting approach to future green analytical chemistry. This method has the potential for extracting polar analytes with poor partition into organic solvents.

What is rotating-electrode gel Electromembrane extraction (re-G-EME)?

This was achieved recently in a new approach termed rotating-electrode gel-electromembrane extraction (RE-G-EME) using a rotating electrode in the AP [ 35 ]. In this concept, the electrode was connected to a modulated speed rotator, and served as both electrode and stirring device ( Fig. 7 ).

Can biopolymers be used as Green membranes?

State-of-the-art to use biopolymers as green membranes is presented. Different strategies for extraction efficiency enhancement are described. Key aspects of biomembranes vs. commercial (artificial) membranes are discussed.

What are alternative membranes for G-EME?

Alternative membranes for G-EME currently include tragacanth gum [ 21, 22 ], chitosan [ 15, 16 ], and polyacrylamide [ 18 ]. Tragacanth gum consists of 60–70% (w/w) bassorin, which swells in water, and a water-soluble fraction termed tragacanthin.