Due to increasing availability of pharmaceuticals from many sources, a need is growing to quickly and efficiently
analyze substances in terms of the consistency and accuracy of their chemical composition. Differences in chemical
composition occur at very low concentrations, so that highly sensitive analytical methods become crucial. Recent
progress in dispersive spectroscopy with the use of 2-dimensional detector arrays, permits for signal integration along a
long (up to 12 mm long) entrance slit of a spectrometer, thereby increasing signal to noise ratio and improving the ability
to detect small concentration changes. This is achieved with a non-scanning, non-destructive system. Two different
methods using P&P Optica high performance spectrometers were used. High performance optical dispersion Raman and
high performance optical absorption spectroscopy were employed to differentiate various acetaminophen-containing
drugs, such as Tylenol and other generic brands, which differ in their ingredients. A 785 nm excitation wavelength
was used in Raman measurements and strong Raman signals were observed in the spectral range 300-1800 cm-1.
Measurements with the absorption spectrometer were performed in the wavelength range 620-1020 nm. Both Raman and
absorption techniques used transmission light spectrometers with volume phase holographic gratings and provided
sufficient spectral differences, often structural, allowing for drug differentiation.