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Integrating Paper Chromatography with Electrochemical Detection for the Trace Analysis of TNT in Soil.

Ryan P, Zabetakis D, Stenger DA, Trammell SA - Sensors (Basel) (2015)

Bottom Line: The probe is a combination of graphite electrodes, filter paper, with ethylene glycol and choline chloride as the solvent/electrolyte.Square wave chromatovoltammograms show the probes have a sensitivity for TNT of 0.75 nA/ng and a limit of detection of 100 ng.In addition, by taking advantage of the inherent paper chromatography step, TNT can be separated in both time and cathodic peak potential from 4-amino-dinitrotolene co-spotted on the probe or in soil samples with the presence of methyl parathion as a possible interferent.

View Article: PubMed Central - PubMed

Affiliation: Science and Engineering Apprenticeship Program, Naval Research Laboratory, Washington, DC 20375, USA. patrick_ryan_@outlook.com.

ABSTRACT
We report on the development of an electrochemical probe for the trace analysis of 2,4,6-trinitrotoluene (TNT) in soil samples. The probe is a combination of graphite electrodes, filter paper, with ethylene glycol and choline chloride as the solvent/electrolyte. Square wave chromatovoltammograms show the probes have a sensitivity for TNT of 0.75 nA/ng and a limit of detection of 100 ng. In addition, by taking advantage of the inherent paper chromatography step, TNT can be separated in both time and cathodic peak potential from 4-amino-dinitrotolene co-spotted on the probe or in soil samples with the presence of methyl parathion as a possible interferent.

No MeSH data available.


Related in: MedlinePlus

Separation of MeP and TNT in sandy soil. (A) Square wave voltammograms at different time points; (B) Time traces at two different potentials; (C,D) 3D square wave chromato-voltammograms. Parameters: Amplitude = 25 mV, Frequency = 60 Hz.
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sensors-15-17048-f005: Separation of MeP and TNT in sandy soil. (A) Square wave voltammograms at different time points; (B) Time traces at two different potentials; (C,D) 3D square wave chromato-voltammograms. Parameters: Amplitude = 25 mV, Frequency = 60 Hz.

Mentions: In the experiment, the ethylene glycol/choline chloride mixture was added to a contaminated soil sample and after an equilibration time of 30 s, the edge of the probe was place into the wet soil. The ethylene glycol/choline chloride mixture with dissolved analyte was transported up to the working electrode. Figure 5 shows the resulting chromatovoltammograms from a 1 g soil sample containing 1000 ng of TNT and MeP. In this case, the electrochemical testing was started immediately after placement into the soil. At 200 s the solvent front reached the working electrode followed by the signal for TNT at 273 s. At 380 s the MeP signal at −0.3 V vs. Ag/AgCl reaches a maximum at the electrode. The presence of the MeP seems to block the TNT electrochemistry. The thiophosphate group of the MeP most likely is the cause due to its longer retention time and electrode blocking characteristics. Nevertheless, it is clear that the two analytes can be individually detected in the soil sample both in time and cathodic peak potential by exploiting the chromatographic and electrochemical aspects of the paper probe.


Integrating Paper Chromatography with Electrochemical Detection for the Trace Analysis of TNT in Soil.

Ryan P, Zabetakis D, Stenger DA, Trammell SA - Sensors (Basel) (2015)

Separation of MeP and TNT in sandy soil. (A) Square wave voltammograms at different time points; (B) Time traces at two different potentials; (C,D) 3D square wave chromato-voltammograms. Parameters: Amplitude = 25 mV, Frequency = 60 Hz.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541921&req=5

sensors-15-17048-f005: Separation of MeP and TNT in sandy soil. (A) Square wave voltammograms at different time points; (B) Time traces at two different potentials; (C,D) 3D square wave chromato-voltammograms. Parameters: Amplitude = 25 mV, Frequency = 60 Hz.
Mentions: In the experiment, the ethylene glycol/choline chloride mixture was added to a contaminated soil sample and after an equilibration time of 30 s, the edge of the probe was place into the wet soil. The ethylene glycol/choline chloride mixture with dissolved analyte was transported up to the working electrode. Figure 5 shows the resulting chromatovoltammograms from a 1 g soil sample containing 1000 ng of TNT and MeP. In this case, the electrochemical testing was started immediately after placement into the soil. At 200 s the solvent front reached the working electrode followed by the signal for TNT at 273 s. At 380 s the MeP signal at −0.3 V vs. Ag/AgCl reaches a maximum at the electrode. The presence of the MeP seems to block the TNT electrochemistry. The thiophosphate group of the MeP most likely is the cause due to its longer retention time and electrode blocking characteristics. Nevertheless, it is clear that the two analytes can be individually detected in the soil sample both in time and cathodic peak potential by exploiting the chromatographic and electrochemical aspects of the paper probe.

Bottom Line: The probe is a combination of graphite electrodes, filter paper, with ethylene glycol and choline chloride as the solvent/electrolyte.Square wave chromatovoltammograms show the probes have a sensitivity for TNT of 0.75 nA/ng and a limit of detection of 100 ng.In addition, by taking advantage of the inherent paper chromatography step, TNT can be separated in both time and cathodic peak potential from 4-amino-dinitrotolene co-spotted on the probe or in soil samples with the presence of methyl parathion as a possible interferent.

View Article: PubMed Central - PubMed

Affiliation: Science and Engineering Apprenticeship Program, Naval Research Laboratory, Washington, DC 20375, USA. patrick_ryan_@outlook.com.

ABSTRACT
We report on the development of an electrochemical probe for the trace analysis of 2,4,6-trinitrotoluene (TNT) in soil samples. The probe is a combination of graphite electrodes, filter paper, with ethylene glycol and choline chloride as the solvent/electrolyte. Square wave chromatovoltammograms show the probes have a sensitivity for TNT of 0.75 nA/ng and a limit of detection of 100 ng. In addition, by taking advantage of the inherent paper chromatography step, TNT can be separated in both time and cathodic peak potential from 4-amino-dinitrotolene co-spotted on the probe or in soil samples with the presence of methyl parathion as a possible interferent.

No MeSH data available.


Related in: MedlinePlus