甲醛固定组织中士的宁与马钱子碱的LC-MS/MS分析

LC-MS/MS Analysis of Determination of Strychnine and Brucine in Formaldehyde Fixed Tissue

目的建立甲醛固定组织中士的宁与马钱子碱的高效液相色谱-串联质谱(LC-MS/MS)分析方法。方法甲醛固定组织经匀浆、离心后,上清液用SCX固相萃取小柱净化,在SB-C18液相色谱柱上以V(0.1%甲酸溶液)∶V(0.1%甲酸乙腈溶液)=75∶25为流动相进行分离,采用电喷雾离子源(ESI)、正离子检测、多反应监测模式进行分析,外标法定量。结果甲醛固定肾、肝组织中士的宁与马钱子碱色谱分离良好,在0.002～2.0μg/g内均具有良好的线性(r>0.996);肾组织中士的宁和马钱子碱的检出限分别为0.06 ng/g和0.03 ng/g,肝组织中均为0.3ng/g;提取回收率均>74.5%,日内及日间精密度均小于8.2%。结论所建LC-MS/MS方法灵敏度高,可用于甲醛固定组织中士的宁和马钱子碱的检测,以满足法医毒物分析的鉴定需求。

Objective To establish a method for determination of strychnine and brucine in formaldehyde fixed tissue by LC-MS/MS analysis. Methods The samples were pretreated with solid phase extraction using SCX cartridges and separated on SB-C18 column with mobile phase 0.1% formic acid ： 0.1% formic acid-acetonitrile （75：25）. Electrospray ionization （ESI） source was utilized and operated in positive ion mode. Multiple reactions monitoring （MRM） mode was applied. External standard method was applied for quantitation. Results The chromatographic separation of strychnine and brucine in formaldehyde fixed nephritic and hepatic tissues resulted successfully. The standard curve was linear in the range of 0.002- 2.0 μg/g for strychnine and brucine in formaldehyde fixed tissues, and the correlation coefficient was more than 0.996. The limits of detection （LOD） of strychnine and brucine in nephritic tissues were 0.06ng/g and 0.03 ng/g, respectively. The LOD of both chemicals were 0.3 ng/g in hepatic tissues. The extraction recovery rate was more than 74.5%. The precision of intra-day and inter-day were both less than 8.2%. Conclusion Strychnine and brucine can be sensitive to be determined in formaldehyde fixed tissue by LC-MS/MS analysis. It can be applied in the forensic toxicological analysis.