Spectrophotometric Determination of Nitrites in Gunpowder Residue on Shooters' Hands

Several methods are described for the qualitative and quantiative spectrophotometric determination of nitrites originated from the gunpowder residues formed in firearms discharge. Detectable amounts of nitrites on shooters' hands were found after firing, whereas on nonshooters' hands the amounts were below the limit of detection. Procedures for providing representative samples are also described. Classic and modified Griess reagents were compared for the detection of nitrites. The latter is shown to be more effective and more convenient for identifying individuals which were involved in a firearm discharge.