TLC profiling of impurities of 1-(3,4-methylenedioxyphenyl)-2-nitropropene an intermediate in MDMA synthesis. Influence of sample preparation methods and conditions

摘要

Thin-layer chromatography (TLC) was employed for screening profiling of impurities of 1-(3,4-methylenedioxyphenyl)-2-nitropropene, an intermediate product of (3,4-methylenedioxy)methamphetamine (MDMA) synthesis (from piperonal). Liquid-liquid extraction (LLE) and solid phase extraction (SPE) were applied to isolate impurities from the drug matrix. The SPE extraction process was performed on C-8 columns and LLE was carried out using n-heptane. The influence of buffer solutions (pH 1, 4, 5, 6, 7, 8, 10, 11, 13, and 14) on the extraction efficiency was investigated. The chromatograms were developed with the use of chloroform: ethyl acetate (98: 2) mixture. The spots of separated impurities were observed under UV light at lambda(exc) = 254 and 366 mn, The proposed semiquantitative criterion of profile (chromatogram) quality has been based on a matrix presentation of TLC patterns. It takes into account the number of spots revealed, differences between R-f values, and intensity of fluorescence, simultaneously.