Determination of diphenylamine stabilizer and its nitrated derivatives in smokeless gunpowder using a tandem MS method

A novel method for determination of diphenylamine (DPA) and its nitrated de rivatives, which are considered as characteristic components in smokeless p owder and gunshot residues, is described. A tandem mass spectrometric metho d is established and mass spectrometer parameters optimized for each compou nd to obtain higher sensitivity. Under optimum conditions, quantitative ana lysis was carried out. The linear ranges are 5.0-200.0, 2.0-200.0 and 5.0-2 50.0 ng ml(-1) and the detection limits are 1.0, 0.5 and 2.5 ng ml(-1) for diphenylamine (DPA), N-NO-diphenylamine (N-NO-DPA) and 3-NO2-diphenylamine (4-NO2-DPA), respectively. Intra-assay and inter-assay precision and accura cy of analysis of these three samples were investigated. Based on the regre ssion Lines obtained above, smokeless samples were analyzed. It was found t hat there are 0.952% DPA, 0.384% N-NO-DPA and 0.128% 4-NO2-DPA in smokeless powder. Recovery tests showed that using cotton swabs, 80.3 +/- 4.9% DPA, 79.6 +/- 3.1% N-NO-DPA and 83.1 +/- 5.4% 4-NO2-DPA could be recovered from human hands.