This article discusses the analysis of a database, i. e. chromatogram and mass spectra that were received from subdivisions of Criminal Expertise Centre of Directorate for Law Enforcement in Transport Means of Russian Ministry of Internal Affairs for Siberian Federal District and former Main Directorate of Federal Narcotics Control Service of the Russian Federation for Krasnoyarsk Territory within 2012–2016 when studying synthetic cannabinoids samples confiscated from illegal trafficking. Typical profile impurities in synthesis reagents were identified, as well as in substances that are fillers for the most wide-spread classes of synthetic cannabinoids.