To investigate if it was possible to leverage this apparent photochemical response for detection, we assessed the time-course change of etonitazene emission in the presence of a series of commercially available e-liquids. Figure shows the averaged spectrum of 9 e-liquids containing 1.5mg/mL etonitazene, deposited onto filters through artificial e-cigarette actuation. We see a significant increase in magnitude at t = 30 s in the spectral region 350-450 nm, indicative of etonitazene photodegradation. No such change is observed in unaltered vape liquid (Figure ) in this spectral window, indicating flavoring compounds are not photochemically active under the conditions used here. Therefore, although etonitazene fluorescence may be convolved with those of flavouring compounds, photochemical degradation provides a means for detection in a similar manner to the detection of THC above. PDs C350 and C365 can be used to monitor changes in nitazene emission magnitude as their spectral windows align to the blue end of the pre-and post-irradiation feature. Incorporation of nitazene detection into the EDD is thus accomplished by setting a threshold for change in magnitude of both C350 and C365 response from t = 0 to t = 30 s. Moreover, Figure shows a time-course plot for metonitazene, showing a similar change in emission on irradiation. Given, the core aromatic moiety of nitzenes are the same (a benzimidazole), and our evidence implies the approach works similarly on different nitazens, we suggest this method could be generically applied to nitazene discrimination in e-cigarettes.