Colorimetric test for trace evidence.
- Grades 9-12
- Estimated class/lab time required: 30 minutes
This simple, two-part presumptive test will help you quickly determine whether or not a surface has recently been exposed to a discharged firearm. Simply wipe down the surface in question, add the chemical reagents, and observe the results. A rapid color-change takes place to verify the presence of nitrates, the main component of gunpowder residue (GSR), while a different color change will verify the presence of heavy metals associated with GSR. Each kit contains complete instructions and enough materials to perform 30 tests.