Rapid quantitative colourimetric tests for trinitrotoluene (TNT) in soil

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Forensic Science

Background:

• 2,4,6-Trinitrotoluene (TNT) is a common explosive.
• Accurate and rapid detection of TNT in soil is crucial for environmental monitoring and site remediation.
• Existing methods for TNT quantification can be time-consuming or require specialized laboratory equipment.

Purpose of the Study:

• To develop a rapid, quantitative colorimetric test for TNT determination in soil.
• To explore an innovative photographic approach for quantifying colorimetric reactions.
• To validate the accuracy and sensitivity of the developed method.

Main Methods:

• Development of a quantitative colorimetric assay for TNT.
• Application of digital photography to measure Red Green Blue (RGB) values.
• Exploitation of the relationship between RGB values and colorimetric product concentration.
• Validation using known concentration standards and spiked soil extracts.

Main Results:

• A wide linear range (1-50 mg/L) was achieved for TNT quantification.
• Low detection limits were obtained (0.73±0.01 mg/L to 3.5±0.4 mg/L).
• The photographic quantification method demonstrated accuracy comparable to spectrophotometric techniques.

Conclusions:

• The developed colorimetric test using photography provides a powerful tool for TNT analysis.
• The technique shows significant potential for adaptation into a rapid, on-site field test for explosives.
• This method offers a viable alternative for field-based environmental and forensic analysis of TNT.