Figure 2

The zero measurement SORS spectra (a) of bottle glass from three commercial spirits drinks (b) vodka in clear glass bottle, gin in brown glass bottle, and Scotch whisky in green glass bottle. Resolve is a handheld SORS (through-barrier) device which takes two measurements, a zero and an offset. The difference between these is that the laser physically moves. The zero measurement can be thought of as traditional backscatter mode, with the Raman signal acquired being biased to the surface. So in the case of the glass bottles that we see here (b), it is generally just the fluorescence of the glass that is observed.