This publication reports analytical properties of three new hallucinogenic substances identified in blotter papers seized from the drug market, namely 25D-NBOMe [2-(2,5-dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine], 25E-NBOMe [2-(4-ethyl-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine] and 25G-NBOMe [2-(2,5-dimethoxy-3,4-dimethylphenyl)-N-(2-methoxybenzyl)ethanamine]. These substances are N-(2-methoxy)benzyl derivatives of the 2C-series of phenethylamine drugs. The applied procedure covered a variety of analytical methods, including gas chromatography with electron impact mass spectrometry (GC-EI-MS; without derivatization and after derivatization with trifluoroacetic anhydride (TFAA)), liquid chromatography-electrospray ionization-quadrupole time of flight mass spectrometry (LC-ESI-QTOF-MS), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR), which made it possible to identify the active components unequivocally. The GC-MS spectra of analyzed compounds were very similar, with dominant ions observed at m/z = 150, 121, and 91. The remaining ions were analogous to those observed for parent substances, namely 2C-D, 2C-E, 2C-G, but their intensities were low. Derivatization allowed determination of molecular masses of the investigated substances. Their exact masses and chemical formulas were confirmed by LC-QTOF-MS experiments and the fragmentation patterns of these compounds following ESI were determined. The tandem mass spectrometry (MS/MS) experiments confirmed that the studied substances were N-(2-methoxy)benzyl derivatives of the 2C-series compounds. Final elucidation of the structures was performed by NMR spectroscopy. The substances were also characterized by FTIR spectroscopy to corroborate the identity of the compounds. Copyright © 2012 John Wiley & Sons, Ltd.