Fig. 2From: Multivariate analysis of energy dispersive X-ray diffraction data for the detection of illicit drugs in border controlThree calibration spectra. Three energy spectra corresponding to three calibration samples: pure diamorphine (black), 50% diamorphine and 50% caffeine (red) and 50% diamorphine and 50% paracetamol (blue). The diffraction spectrum for each sample was recorded for 28Â s. A different distribution of counts is noticeable for the three different mixturesBack to article page