Capillary electrophoresis chemiluminescent detection system equipped with a two‐step postcolumn flow interface for detection of some enkephalin‐related peptides labeled with acridinium ester

Abstract

Despite its low equipment cost and simple design, as one of the sensitive detectors for CE, the chemiluminescence (CL) detector was less developed compared to the detectors of MS and LIF. The main reasons were the limitation of CL reagents, the repeatability problems and the relatively low sensitivity compared to LIF. In this paper, a highly sensitive CE-CL detection system was developed for detection of some enkephalin-related peptides labeled with acridinium ester. A new detection interface was designed for CE with CL detection of acridinium ester and its labeled analytes. The interface included two sections: one was used to acidify the capillary outflow so that the corresponding acridinium pseudo-base form can be changed into acridinium ester form by adding excess acid to the system; the other was designed to provide a suitable solution to produce the CL from acridinium ester. The effect factors, such as pH, the concentration of reaction reagents and the flow rates of the reagents, were investigated. The results showed that acridinium ester had similar CL properties in this interface when pH values of CE BGE were changed from 2.0 to 10.8. The interface was used to detect acridinium ester and three acridinium ester-labeled enkephalin-related peptides, the corresponding LODs were found to be in the attomole range. This CL detection system proved to be of high sensitivity, good repeatability, and relatively low cost.

A new method for preparation of an etched porous joint for capillary electrophoresis and its pore‐size evaluation

“…The homemade CE apparatus reported previously 27 was used for the detection of solutions I and II. A 40 cm‐long bare fused‐silica capillary with 75 μm id was used as the separation capillary.…”

Recent developments in instrumentation for capillary electrophoresis and microchip‐capillary electrophoresis

“…A highly sensitive chemiluminescence detection system was also developed for detection of enkephalin-related peptides labeled with acridinium ester [90]. The interface included two sections to 1) acidify the capillary outflow (so that the corresponding acridinium pseudo-base form can be changed into acridinium ester form by adding excess acid to the system), and 2) provide a suitable solution to produce the chemiluminescence from acridinium ester.…”

Highly sensitive trivalent copper chelate-luminol chemiluminescence system for capillary electrophoresis detection of epinephrine in the urine of smoker

“…CE coupled with CL detection has been successfully applied for quantifying some compounds including peptides [23,24], amino acids [25,26], drugs [27,28] and metal ions [29,30]. For the determination of EP using CE-CL strategy, EP is usually derivatized by CL reagent such as N-(4-aminobutyl)-N-ethylisoluminol [13,28].…”