MATRIX: Gauze Wipe
ANALYTE: TNT and RDX
LIMIT OF DETECTION: TNT: 7 ug/100 cm2, RDX: 8 ug/100 cm2
This application describes a field screening method for determining TNT or RDX concentrations on gauze wipes. Acetone is used to extract the TNT or RDX from the gauze wipe and a chemical reaction is induced that causes a color change indicative of TNT or RDX in the sample. The TNT or RDX concentrations are estimated from the absorbance at 540 nanometers (nm) and 510 nanometers (nm) respectively on a Hach DR2000/2010 spectrophotometer.
Extraction and analysis should be performed in a well ventilated area. Laboratory technicians should wear chemical resistant gloves and safety glasses. Use gloves during the entire procedure.
TNT Ensys Soil Test System or RDX Ensys Soil Test System. Alumina-A cartridge (if running RDX analysis and presence of nitrates/nitrites is suspected). Gauze wipes. Reagents: acetone, distilled/deionized water. Equipment: HACH DR2000/2010.
Refer to the TNT or RDX Ensys Soil Test System User’s Guide included in your test kit for detailed instructions.
1. Soak gauze wipe in acetone. Remove excess back into extraction jar.
2. Wipe a 100cm2 (10 cm x 10 cm) surface area with the gauze wipe.
3. SDI can provide 100 cm2 wipe templates upon request (Part #1064000).
4. Place the 100 cm2 surface area wipe sample in Bottle 1 (in place of the 10g soil sample referred to in the TNT or RDX Ensys Soil Test System User’s Guide) and extract with 50 mL of acetone as described in the kit procedure.
5. Continue with protocol as described in the User’s Guide to analyze samples.