In recent years, several newer designer drugs of the so-called 2C series such as 2C-D, 2C-E, 2C-P, 2C-B, 2C-I, 2C-T-2, and 2C-T-7 have entered the illicit drug market as recreational drugs. Some fatal intoxications involving 2C-T-7 have been reported. Only scarce data have been published about analyses of these substances in human blood and/or plasma. This paper describes a method for screening and simultaneous quantification of the above-mentioned compounds and their analog mescaline in human blood plasma. The analytes were analyzed by gas chromatography/mass spectrometry in the selected-ion monitoring mode, after mixed-mode solid-phase extraction (HCX) and derivatization with heptafluorobutyric anhydride. The method was fully validated according to international guidelines. Validation data for 2C-T-2 and 2C-T-7 were unacceptable. For all other analytes, the method was linear from 5 to 500 mu g/L and the data for accuracy (bias) and precision (coefficient of variation) were within the acceptance limits of +/- 15% and < 15%, respectively (within +/- 20% and < 20% near the limit of quantification of 5 mu g/L). Copyright (c) 2005 John Wiley & Sons, Ltd.