Electrochemical Detection with Preconcentration: Nitroenergetic Contaminants

Chemosensors

Brandy J. Johnson²  Mansoor Nasir¹  Ronald L. Siefert³  Iwona A. Leska⁴  Jeffrey S. Erickson²  Paul T. Charles²  Brian J. Melde² 

[1] Biomedical Engineering, Lawrence Technical University, Southfield, MI 48075, USA; E-Mail:;Center for Bio/Molecular Science and Engineering, US Naval Research Laboratory, Washington, DC 20375, USA; E-Mails:;US Naval Academy, Annapolis, MD 21402, USA; E-Mail:;NOVA Research Incorporated, Alexandria, VA 22308, USA; E-Mails:

关键词: nitroenergetic;    trinitrotoluene;    dinitrotoluene;    solid phase extraction;    organosilica;    environmental monitoring;    field trials;   

DOI  :  10.3390/chemosensors2020131

来源: mdpi

【 摘 要 】

This effort evaluated the potential of two prototype devices for enhanced electrochemical detection of 2,4,6-trinitrotoluene (TNT) and dinitrotoluene (DNT) following preconcentration using an organosilicate sorbent. The bench-scale prototype provides adsorption of the targets from aqueous solution followed by elution in a mixture of methanol and potassium chloride (KCl). Following elution, the eluant is diluted using an aqueous KCl solution to provide sufficient electrolyte for electrochemical analysis. Concentrations of methanol greater than 50% were detrimental to sensor performance and lifetime. Calibration of the electrochemical sensor was completed and results of electrochemical analysis were compared to those of HPLC analysis over a range of concentrations and in varied matrices. TNT detection was found to be consistent and detection limits were improved from 200 ppb to 3 ppb depending on the sample volume utilized. DNT detection showed higher variability and significantly greater false response rates. On the basis of these results, a second, more advanced, prototype was developed and utilized in limited field trials with the intention of moving the technology toward in situ applications.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.