Microchip Capillary Electrophoresis with Electrochemical Detection of Thiol-Containing Degradation Products of V-Type Nerve Agents

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• 作者：Joseph Wang ; Jiri Zima ; Nathan S. Lawrence ; Madhu Prakash Chatrathi ; Ashok Mulchandani ; and Greg E. Collins
• 刊名：Analytical Chemistry
• 出版年：2004
• 出版时间：August 15, 2004
• 年：2004
• 卷：76
• 期：16
• 页码：4721 - 4726
• 全文大小：108K
• 年卷期：v.76,no.16(August 15, 2004)
• ISSN：1520-6882

文摘

A microchip protocol for the capillary electrophoresisseparation and electrochemical detection of thiol-containing degradation products of V-type nerve agents is described. The microchip assay relies on the derivatizationreaction of 2-(dimethylamino)ethanethiol (DMAET), 2-(diethylamino)ethanethiol (DEAET), and 2-mercaptoethanol(ME) with o-phthaldialdehyde in the presence of theamino acid valine along with amperometric monitoring ofthe isoindole derivatives. Both off-chip and on-chip derivatization reactions have led to highly sensitive and rapiddetection of the thiol degradation products. Variousparameters influencing the derivatization, separation, anddetection processes were examined and optimized. Theseinclude the amino acid co-reagent, reagent-mixing ratio,reaction time, injection time, separation voltage, anddetection potential. The chip microsystem offers a rapid(<4 min) simultaneous detection of micromolar concentrations of DMAET, DEAET, and ME. Linear calibrationplots were observed for the V-type nerve agent thioldegradation products, along with good stability and reproducibility (RSD < 8.0%). Detection limits of 5 and 8M were obtained for the off-chip reaction of DMAET andDEAET, respectively, following a 2-s injection. The suitability for assays of environmental matrixes was demonstrated for the determination of DMAET and DEAET inuntreated tap and river water samples. The favorableanalytical performance makes the new microfluidic deviceattractive for addressing the needs of various securityscenarios.