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

Abstract

A new and simple open‐tubular CEC (OT‐CEC) method with a novel diblock copolymer poly(butyl methacrylate)71‐block‐poly(glycidyl methacrylate)9 as the coating based on its self‐assembled properties has been developed. Compared with the bare capillary, this coating could act as a surfactant and improve the separation efficiency of aromatic amines. Meanwhile, the effects of pH value, buffer concentration, and the copolymer block ratio on the separation efficiencies were investigated in detail. It has been found that the three tested aromatic amines could be baseline separated by the OT‐CEC method with the cooperation of SDS. The proposed OT‐CEC method showed good repeatability with RSDs <3.2% for testing the EOF. Moreover, it was also well validated by satisfactory linearity and favorable recovery, which ensured its successful application in the separation of aromatic amines in nail polish samples. The results revealed the potential applicability of the OT‐CEC method in cosmetic analysis.

Open tubular‐capillary electrochromatography: Developments and applications from 2013 to 2015

“…Lei and Zhang have separated neutral and charged compounds using a sol‐gel matrix containing octyl (C 8 ) and amine groups . Sun and co‐workers have separated aromatic amines employing a diblock copolymer with hydrophobic poly(butylmethacrylate) segments and hydrophilic poly(glycidyl methacrylate) segments . Zhu and coworkers have separated neutrals and aromatic acids using core‐shell magnetic nanoparticles (Fig.…”

“…Table A‐2 summarizes examples of the use of preformed SP materials, i.e. phospholipid vesicles , block copolymers , zeolitic imidazole frameworks , derivatized chitosan , and bacterial antibiotic‐based materials, all of which can be immobilized onto the inner wall of fused silica capillaries. Fabrication of phospholipid vesicle‐based SP materials can be achieved by aminopropylsilylation of the surface silanol groups, followed by treatment with glutaraldehyde, forming iminoaldehyde functionalities.…”

“…This intermediate can then be used in reactions with the primary amino groups of liposomes, derived, for example, from 1‐palmitoyl‐2‐oleyl‐ sn ‐glycero‐3‐phosphocholine, 1‐palmitoyl‐2‐oleoyl‐ sn ‐glycero‐3‐phospho‐L‐serine, or cholesterol . In a similar manner, the synthesized block copolymer poly(butyl methacrylate) 71 ‐ block ‐poly‐(glycidyl‐methacrylate) 9 can be introduced via 3‐aminopropyltriethoxysilane (APTES) modification of the capillary . On the other hand, the zeolitic imidazolate framework (ZIF‐90) was firstly modified with APTES, and then covalently attached to a bare silica capillary .…”

“…Separations in OT‐CEC are dictated inter alia by the electrophoretic mobility of the analytes, the magnitude of the EOF and the chromatographic affinity of the analytes for the coating on the inner capillary wall. The types of interaction encountered may be hydrophobic , aromatic as manifested via the classically known π–π stacking , hydrophilic (dipole–dipole and hydrogen bonding) , and ionic interactions . These interactions are responsible for the reversed‐phase, ion‐exchange, hydrophilic interaction, mixed mode, and chiral characteristics of these separations, as indicated in Table , third column.…”

“…Low molecular‐weight organic and small biomolecules have been the most common test compounds to evaluate the separation performance of OT‐CEC capillaries. Table lists specific examples of these analytes that fall into different compound categories comprising (i) neutrals such as alkylbenzenes , polyaromatic hydrocarbons , and binaphthalenes ; (ii) organic acids like dicarboxylic acids , aromatic acids or esters as well as aromatic alcohol racemates and phenols ; (iii) organic bases like amines and anilines , heterocyclic bases like pyridines and pterins ; (iv) inorganic anions like nitrite and nitrate ; and (v) inorganic heavy metal cations .…”