Separation and Detection of Nitrophenols at Capillary Electrophoresis Microchips with Amperometric Detection

Abstract

A miniaturized analytical system for the separation and amperometric detection of toxic nitrophenols, based on the coupling of a micromachined capillary electrophoresis (CE) chip with a glassy carbon detector is described. This microsystem enables a rapid (120 s/sample) simultaneous determination of five priority nitrophenolic pollutants (2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, and 2-methyl-4,6-dinitrophenol). These compounds can be detected down to the 1 Â 10 À5 M level using a 15 mM phosphate buffer pH 7.2 (containing 1.3 mM a-cyclodextrin) as running solution on 77 mm long microchannel by applying a separation voltage of 3000 V and a negative potential of À 0.7 V (vs. Ag /AgCl wire). Applicability to ground water samples was demonstrated.

The Use of Silver Solid Amalgam Working Electrode for Determination of Nitrophenols by HPLC with Electrochemical Detection

“…Limit of quantitation (10 S/N), is always 3.3 times higher than limit of detection, therefore, it is not repeated in Table 2. The achieved limits of detection are comparable with limits of detection achieved with capillary electrophoresis on microchips with amperometric detection [4] and is slightly higher then with UV spectrophotometric detection. However, electrochemical detection based on reduction of nitro group is more selective.…”

Biosensor technology: Technology push versus market pull

“…Novel approaches are under development to miniaturize such integrated system to minimize consumables, analysis time and improve reliability. The development of microscale separation devices, particularly micromachined capillary electrophoresis chips coupled with amperometric detection, has received significant attention in recent years (Fischer et al, 2006). Integration of a miniaturized biosensor with a separation scheme will continue to be a subject of intensive investigation.…”

Electrochemical Behavior of o‐Nitrophenol at Hexagonal Mesoporous Silica Modified Carbon Paste Electrodes

“…Therefore, more and more researchers had paid attention to the analysis and determination of o-NP. Though, various quantitative methods and mechanism have been reported [12,13], such as HPLC [14], CE [15,16], spectrophotometry [17,18] and electroanalytical methodology [19,20], the application of HMS in electroanalysis for o-NP had not been reported yet.…”