Professor Wai’s research is the first to show that synchronous scanning plus the second derivative can distinguish among four likely reduction products in a TNT-based explosive mixture. Synchronous scanning itself has advantages over other identification methods, because it is rapid, sensitive, and selective. Taking the second derivative helps, in addition, to distinguish various products whose spectra overlap. The use of an agent (fluorescamine, in this case) to form a derivative compound reaches a lower limit of detection. HORIBA Jobin Yvon spectrofluorometers are capable of recording and analyzing weak fluorescence such as that presented here.