A well‐defined block copolymer serving as surfactants in separation of 1,4‐dihydropyridines by open‐tubular capillary eletrochromatography

Abstract

A novel series of diblock copolymers, poly(butyl methacrylate)(n) -block-poly(glycidyl methacrylate)(m) [P(BMA)(n) -b-P(GMA)(m) ], were synthesized by atom transfer radical polymerization and developed as covalent coating of capillaries. The excellent performance of this coating in separation of three 1,4-dihydropyridines (DHPs) derivatives (amlodipine, nicardipine, nitrendipine) was achieved when the diblock copolymers self-assembled into micelles, which was confirmed by transmission electron microscopy, dynamic light scattering, and atom force microscopy. Meanwhile, the effects of block ratio n/m, pH value, buffer concentration, and organic solvents on the separation of 1,4-DHPs were investigated in detail. Then, the relationship between the morphologies of copolymers and the separation resolutions of 1,4-DHPs was discussed. Furthermore, the proposed method exhibited good run-to-run and column-to-column precision with relative standard deviations of electroosmotic flow less than 3.0%. It was also validated with linearity of three 1,4-DHPs in the range of 0.01-1.80 mM (r(2) ≥ 99.7%), efficient recovery (94-103%), and good repeatability (≤ 3.8%). In addition, three 1,4-DHPs were successfully separated in the spiked human serum sample, which indicated the potential utility of this method in biological sample analysis.

Stable neutral double hydrophilic block copolymer capillary coating for capillary electrophoretic separations

“…On the first day the EOF was +1.23 × 10 −2 /Vs ( n = 5) and from the second day to the eighth day the EOF varied between +2.8 × 10 −10 and +5.8 × 10 −10 m 2 /Vs ( n = 5), and then it started to increase stepwise proving that the coating can be used only during the first 8 days. Although permanent coatings prepared from block copolymers can be stable even for 2–3 months, their coating processes include time‐consuming steps and harsh conditions . Semipermanent coatings prepared from block copolymers can have lifetimes up to 40 h and over 30 consecutive runs , but the EOF is suppressed only by one magnitude.…”

“…They have been widely used for instance in nanomaterials, drug delivery, and other pharmaceutical applications . Block copolymers have also been recently used as coating materials and as separation media . Amphiphilic block copolymers have the capability to form micelles and other self‐assembled nanostructures in water.…”

Separation of aromatic amines by an open-tubular capillary electrochromatography method

“…One homopolymer P(GMA) and two different kinds of block copolymers P(BMA) m ‐b‐P(GMA) n were synthesized in our lab, and the preparation procedure was described in our previous work . Scheme S1 (Supporting Information) illustrates the coating procedure.…”

Open tubular capillary electrochromatography with an N‐phenylacrylamide‐styrene copolymer‐based stationary phase for the separation of anomers of glucose and structural isomers of maltotriose

“…OT‐CEC is one of the useful CEC‐capillary format which accounts for the separation of various classes of compounds and bio‐molecules such as proteins, peptides, and glycoproteins, etc. . CEC combines the advantageous effects of both CE and HPLC .…”