应用高效液相色谱串联质谱法分析头孢噻肟钠的杂质谱

Analysis of Impurity Profile of Cefotaxime Sodium by HPLC-MS

目的建立高效液相色谱串联质谱检测器的方法,分析头孢噻肟钠的杂质谱。方法采用Shimadzu-LCMS-IT-TOF液质联用仪,Waters XBridge Shield(RP18,4.6 mm×250 mm,5μm)色谱柱,以20 mmol·L^(-1)乙酸铵(调pH至6.25)-甲醇(92∶8)为流动相A,20 mmol·L^(-1)乙酸铵-甲醇(60∶40)(调pH至6.25)为流动相B,梯度洗脱,流速1.0 mL·min^(-1),质谱检测器采用电喷雾离子源(ESI),正负离子扫描;扫描范围:m/z 150~900;加热模块温度:200℃;曲型脱溶剂管(CDL)温度200℃;雾化气流速1.5 L·min^(-1);干燥气体压力:94.0 kPa;柱后分流1∶4。检出杂质结构的鉴定方法根据有无杂质对照品而异:对于有对照品的杂质,通过比较其与对照品的色谱和质谱行为来确定结构;对于无对照品的未知杂质,则以已知结构物质如头孢噻肟为模型,通过分析已知物与未知杂质多级质谱行为的异同性推定其结构。结果头孢噻肟钠原料中检出头孢噻肟异构体、二聚体等26个有关物质,包括已知杂质10个和未知杂质16个,对各杂质的结构进行了推测和来源归属。结论本实验建立的HPLC-UV-IT-TOF方法及研究结果对头孢噻肟钠的质量控制和工艺评价具有指导意义。

OBJECTIVE To establish an HPLC-MS method for the analysis of the impurity profile of eefotaxime sodium. METHODS Shimadzu-LCMS-IT-TOF was used with Waters XBridge Shield （ RP18,4. 6 mm × 250 mm, 5 -m） column. Mobile phase A was 20 mmol·L^-1 ammonium acetate （pH adjusted to 6. 25 ）-methanol （92：8 ） , and mobile phase B was set at 20 mmol·L^-1 ammonium acetate-methanol （60： 40） （pH adjusted to 6. 25）. Gradient elution was performed at a flow rate of 1.0 mL·min^-1. ESI source was used. Positive and negative ion scanning was conducted in the range of m/z 150 -900. The heating temperature was 200 ℃, CDL temperature was maintained at 200 ℃, atomization gas flow rate was 1.5 L·min^-1, dry gas pressure was 94. 0 kPa, and the post-column diversion ratio was 1 ： 4. Some related substances in cefotaxime sodium were identified by comparing the retention time in chromatography, [ M ＋ H]^＋ spectrum and MS^2 spectrum with those of reference substances, the others which haven＇t reference substances were deduced or speculated by analyzing the MS^2 or MSn fragmentation with the help of a rule summarized from the MS2 fragmentation of cefotaxime sodium and the reference substances of system suitability impurities. RESULTS Twenty-six related substances were separated and detected in the sample, all of which were identified or deduced. They were cefotaxime sodium isomeric compounds and homologs generated during the production process or degradation products. CONCLUSION The method can be applied in the identification and qualitative analysis of the related substances of cefotaxime sodium and the quality control and optimization of the synthesis of cefotaxime sodium.