Premium
Determination of heavy metal ions by microchip capillary electrophoresis coupled with contactless conductivity detection
Author(s) -
Liu Benyan,
Zhang Yi,
Mayer Dirk,
Krause HansJoachim,
Jin Qinghui,
Zhao Jianlong,
Offenhäusser Andreas,
Xu Yuansen
Publication year - 2012
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201100626
Subject(s) - capillary electrophoresis , detection limit , conductivity , analytical chemistry (journal) , chemistry , thermal conductivity detector , metal , buffer (optical fiber) , chromatography , metal ions in aqueous solution , electrophoresis , materials science , electrical engineering , gas chromatography , engineering , organic chemistry
An integrated detection circuitry based on a lock‐in amplifier was designed for contactless conductivity determination of heavy metals. Combined with a simple‐structure electrophoresis microchip, the detection system is successfully utilized for the separation and determination of various heavy metals. The influences of the running buffer and detection conditions on the response of the detector have been investigated. Six millimole 2‐morpholinoethanesulfonic acid + histidine were selected as buffer for its stable baseline and high sensitivity. The best signals were recorded with a frequency of 38 k H z and 20 V pp . The results showed that M n 2+ , C d 2+ , C o 2+ , and C u 2+ can be successfully separated and detected within 100 s by our system. The detection limits for five heavy metals ( M n 2+ , P b 2+ , C d 2+ , C o 2+ , and C u 2+ ) were determined to range from about 0.7 to 5.4 μ M . This microchip system performs a crucial step toward the realization of a simple, inexpensive, and portable analytical device for metal analysis.