Objective To establish a kind of simple ,rapid ,accurate and reliable method to determine the phenobarbital in the biomaterial .Methods We pre‐treated biomaterial by the method that the reagent of acetone∶water (v/v 8∶2) was firstly used to soak the biomaterial ,and then we took use of ethyl acetate as reagent to extract the phenobarbital of the biomaterial in the present of pH=3-4 .We finally employed GC‐MS to determine these samples .On the one hand ,we not only took advantage of the reten‐tion time of the phenobarbital in total ion current (TIC) but also took advantage of the characteristic fragment ions of phenobarbital in mass spectrogram as qualitative basis .On the other hand ,we took advantage of the external standard method as quantitative ba‐sis .Results The method had the characteristics of the simple and easy operation .There was hardly background interference and there was good separation effect in the method .The method also had the characteristics of fast analytical speed such as the retention time of the phenobarbital was 8 .385 min .The characteristic fragment ions of phenobarbital was m/z 204 and m/z 232 .The charac‐teristic fragment ions of m/z 204 was served as quantitative ion fragments and we employed the external standard method to quanti‐fy in the method .In short ,the average recovery rate of the method was 87 .35% .Relative standard deviation (RSD) was 5 .43% in the method .The lowest limit of detection (LLOD) was 0 .005 mg/mL .Conclusion The method showes satisfactory result that it could be applied to determine the phenobarbital of the biomaterial of forensic toxicological analysis .

Objective The study aimed to establish a kind of simple,rapid,accurate and reliable method in order to simultaneous determine the phenobarbital,ibuprofen and nikethamide in the biomaterial. Methods The biomaterial were pre-treated with ethanol(v/v 95%)at pH 3~4 and then was extracted with ethyl acetate at pH 3~4 and 10~11,respectively. Finally,phenobarbital,ibuprofen and nikethamide in the biomaterial were simultaneous detected by GC-MS. The retention times and relevant characteristic fragment ions of the three substances in the total ion current(TIC)and the mass spectrogram could be used as the basis of qualitative analysis. Results The method was simple and easy operation. It has the characteristics of low background interference,good separation effect and fast analytical speed. The retention times of phenobarbital,ibuprofen and nikethamide were 8.472 min,7.087 min and 6.655 min,respectively. The characteristic fragment ions of phenobarbital were 204 and 232(m/z),of ibuprofen were 161 and 206(m/z),and of nikethamide were 106 and 177(m/z). Conclusion The method showed a satisfactory result that it could be applied to simultaneous determine phenobarbital,ibuprofen and nikethamide of the biomaterial for forensic toxicological analysis.