Anion polymeric monolithic

Figure 29 Separation of the nonsteroidal anti-inflammatory drugs ibuprofen (peak 1), naproxen (2), ketoprofen (3), and suprofen (4) in anion-exchange CEC mode using a strong anion-exchange monolithic column. Conditions on-column alkylated monolith prepared from mixtures consisting of 8% 2-dimethylaminoethyl methacrylate, 24% 2-hydroxyethyl methacrylate, 8% ethylene dimethacrylate, 20% cyclohexanol, 40% 1-dodecanol UV-initiated polymerization at room temperature for 16 h cfpmode= 1423 nm. Column dimensions inner diameter 0.1 mm, total length 335 mm, effective length 250 mm. Mobile phase 0.4 mol/L acetic acid and 4 mmol/L triethylamine in acetonitrile/methanol (60/40), voltage -25 kV, injection -5 kV for 5 s, temperature 50°C, UV detection at 250 nm. (Reprinted from Ref. 127, with permission.)...

Hutchinson, J.P. Zakaria, P. Bowie, A.R. Macka, M. Avdalovic, N. Haddad, P.R. Latex-coated polymeric monolithic ion-exchange stationary phases. 1. Anion-exchange capillary electrochromatography and in-line sample preconcentration in capillary electrophoresis. Anal. Chem. 2005, 77, 407 16. 

SPE is an exhaustive and almost solvent-free sample preparation technique. Typically, a tube is filled with a sorbent, which can be porous particles or a polymerized monolith. Various interactions are used to extract analytes from complex samples. Many of the commercially available SPE systems are for single use, but some, like RAM (restricted access materials) and MIP (molecular imprinted polymers), are typically obtained as reusable extraction devices. As will be discussed in detail, the extraction sorbents mainly function as normal phase, reversed phase, cation exchange, anion exchange, or a combination of these. 

The epoxide groups of a polyglycidyl methacrylate-co-ethylene dimethacrylate monolith readily react with diethylamine to create a weak anion exchange column. This monolithic column is characterized by fast mass transport kinetics leading to excellent resolution. The columns seem to be stable, and the specific capacity is 40-mg/g medium for ovalbumin [60,62]. More recently, graft polymerization within... 

This new synthesis method provides an improved means of preparing monolithic media compatible with stationary-phase synthesis techniques developed for particulate media. The new technique is compatible with polymeric column hardware and does not require covalent bonding of the monolith to the inner column wall. The use of prepolymerized particles circumvents issues associated with shrinkage problems that are characteristic of conventional monolith syntheses (see Section 3.4.1.6) while providing excellent efficiency for small-molecular weight anions, even under isocratic conditions. 

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