ABSTRACT
Objective To establish a method to identify unknown samples based on combined use of gas chromatography-mass spectrometry （GC-MS）, high resolution mass spectrometry （HRMS） and nuclear magnetic resonance spectrum （NMR） technique. Methods The unknown samples were dissolved in methanol solution containing internal standard SKF525A and detected by GC-MS and HRMS. The mixed samples were separated and purified by silica gel column chromatography, and then dissolved in methanol-d4 solution for structural analysis of 1H nuclear magnetic resonance spectroscopy （1H NMR）. Results The characteristic fragment ions （m/z） were 86.1 （base peak）, 71.2, 121.1, and 149.0, and the accurate mass number of molecular ion peak was measured by HRMS to be 236.128 89. By combined use of data analysis and database comparison, a new psychoactive substance of the cathinone class, Dibutylone, was detected in the sample, and the sample also contained a small amount of caffeine. The sample was purified, then identified using 1H NMR, and was further confirmed to be Dibutylone. In addition, the GC-MS retention time and characteristic fragment ions of the main components of the sample were consistent with those of Dibutylone reference material. Conclusion The method established in this study can be used for the identification of Dibutylone in mixed samples.