Covalent modification of fused silica capillaries with quaternized polyamines to achieve robust and stable anodic electroosmotic flow

Abstract

Synthetic chemistry originally developed for the manufacture of chemically stable silica polyamine composites was adapted for the modification of fused silica capillaries for application in CE. Polyethyleneimine (PEI) and polyallylamine (PAA) were covalently bonded to the interior surface of fused silica capillaries utilizing 3-chloropropyltrichlorosilane (CPTCS) or 3-glycidoxypropyl-trimethoxysilane (GPTMS) to anchor the polymers to the surface. The surface-bound polymers were subsequently quaternized using methyl iodide (MeI). The resulting modified capillaries were studied using CE, and were shown to provide reproducible, stable, and robust anodic EOF throughout the pH range of 2-10. Surface modifications utilizing CPTCS could be rinsed with up to 6 M HCL or 1 M NaOH without significant loss of surface modifier. The utility of the modified capillaries for the separation of simple anions and cations was demonstrated.

A covalent capillary coating of diazoresin and polyglycerol dendrimer for protein analysis using capillary electrophoresis

“…Following the decomposition of the diazo groups, the hydrogen bonds between DR and PG dendrimer were converted into covalent bonds [42]. The unique photocrosslinking reaction of DR has been used for the fabrication of covalently attached self-assembly films [43], hollow microcapsules [44], and biochips [45]. The inset of Fig.…”

CE of inorganic species – A review of methodological advancements over 2009–2010

“…Unusual use of DMF under acidic NACE conditions was reported 89, where it acts the part of a probe for indirect UV detection of metal ions. Semi‐permanent coating of the capillary with dioctadecyldimethylammonium chloride was applied to enhance separation efficiency of a series of organotin compounds 90, while capillaries modified covalently with quaternized polyamines were effective to provide reproducible, stable, and robust anodic EOF for separating a range of inorganic anions 91. In another report, the zwitterionic phospholipid polymers were immobilized (by ionic interactions) onto the capillary wall for application to simultaneous separation of phosphate compounds and anions 92.…”

Layer-by-layer self-assembly of polydopamine/gold nanoparticle/thiol coating as the stationary phase for open tubular capillary electrochromatography

“…7 To obtain chemically bonded phases with good stability and long lifetime, tedious and time-consuming processes are required in general. 7,12 Deposition of a physical coating on the capillary inner surfaces is an easier approach to fabricate OT-CEC columns with low cost, 7,13 although the coating is less stable and has a shorter lifetime than those of the covalent coating in some instances. On the other hand, the low separation capability of OT-CEC caused by the low phase ratio of the stationary phase hinders its applications.…”