目的 采用顶空进样气相色谱三重四级杆质谱联用（HS-GC-MS/MS）法测定富马酸丙酚替诺福韦中微量的基因毒性杂质N-亚硝基二甲胺（NDMA）。方法 采用三重四极杆GC-MS/MS，Agilent VF-WAX ms（30 m×0.25 mm，1 μm）色谱柱，载气：氦气；恒流模式1.0 mL·min^-1；程序升温，进样口温度230℃，顶空温度130℃；质谱采用电子轰击电离源（EI），电离能量为70 eV，离子源温度230℃，多反应监测（MRM）模式进行检测，溶剂为N-甲基吡咯烷酮（NMP）。进行专属性、系统适用性、检测限与定量限、线性与范围、准确度、精密度、溶液稳定性、耐用性考察。结果 NDMA与相邻色谱峰之间分离效果良好；NDMA在7.0～105.0 ng·mL^-1线性关系良好，检测限为3.5 ng·mL^-1，定量限为7.0 ng·mL^-1；NDMA低、中、高质量浓度（56、70、84 ng·mL^-1）回收率为95.6%～109.3%，RSD为4.0%（n=9）；重复性试验NDMA质量浓度RSD为6.5%，中间精密度RSD为6.1%；对照品溶液室温放置24 h稳定，供试品溶液室温放置90 h内溶液稳定；保持其他条件不变，分别改变进样口温度（230、225、235℃）、离子源温度（230、225、235℃）、载气体积流量（1.0、0.9、1.1 mL·min^-1）、顶空温度（130、128、132℃），方法耐用性良好。结论 所建立的方法准确度好、灵敏度高、简便可靠，对仪器污染小，可用于富马酸丙酚替诺福韦中NDMA的质量控制。

Objective To establish a HS-GC-MS/MS method for the microdetermination of N-nitrosodimethylamine (NDMA) in tenofovir alafenamide fumarate. Methods GC-MS/MS was used, and the separation was performed on a Agilent VF-WAX ms column (30 m×0.25 mm, 1 μm) with temperature programmed. Carrier gas:helium, Constant current mode of 1.0 mL·min^-1. The inlet temperature was 230℃ and flow rate was 1.0 mL·min^-1, headspace temperature was 130℃. Mass spectrometry was used with EI source, the voltage was 70 eV, ion source temperature was 230℃, and detected with selected ion monitoring (MRM) data acquisition mode. The samples were dissolved in NMP. Specificity, system applicability, limit of detection and limit of quantification, linearity and range, accuracy, precision, solution stability and durability were investigated. Results The separation between NDMA and adjacent autobiographic peaks was effective, NDMA was well correlated with the linearity range between 7.0-105.0 ng·mL^-1. The limit of detection of NDMA was 3.5 ng·mL^-1 and the limit of quantitation was 7.0 ng·mL^-1. The average recoveries of NDMA were between 95.6% and 109.3% at low, middle and high concentration, with the RSD (n=9) of 4.0%. RSD of reproducibility test NDMA was 6.5%, and RSD of intermediate precision was 6.1%. The control solution was stable at room temperature for 24 h, and the test solution was stable at room temperature for 90 h. The inlet temperature (230, 225, 235℃), ion source temperature (230, 225, 235℃), carrier gas volume flow rate (1.0, 0.9, 1.1 mL·min^-1), and headspace temperature (130, 128, 132℃) were changed with other conditions unchanged. The durability of the method was good. Conclusion The method is accurate, highly sensitivite, simple and reliable with less pollution to the instrument, and it can be used for the quality control of the genotoxic impurity NDMA in tenofovir alafenamide fumarate.

R991

中国医学科学院医学与健康科技创新工程项目资助（2019-I2M-5-020）；天津市科技计划项目（18YFZCSY00090）