Examination of paints by trace element analysis.

Trace element analysis using neutron activation analysis is effective and valuable, particularly in the examination of white household paint. Although physical appearance and resin composition are generally similar in these paint samples, trace element composition provides an effective way of distinguishing among them. In the case of automobile paint samples, NAA serves as an important additional technique for discrimination. The technique is important when sample sizes are very small. The technique developed takes a few minutes for sample preparation, a few hours of irradiation time (during which the examiner's presence is not required), and then a few minutes for counting and obtaining quantitative multielement concentration patterns. A technician can easily handle 30 to 50 samples per day.