Xu Yu, Wang DanDan, Tang Lan, Wang Jian
Zhejiang University of Technology, Hangzhou 310014, China.
Zhejiang University of Technology, Hangzhou 310014, China; Zhejiang Institute for Food and Drug Control, Hangzhou 310052, China.
J Pharm Biomed Anal. 2017 Oct 25;145:742-750. doi: 10.1016/j.jpba.2017.07.063. Epub 2017 Aug 2.
Eleven unknown allergic impurities in cefodizime, cefmenoxime and cefonicid were separated and characterized by a trap-free two-dimensional high performance size exclusion chromatography (HPSEC) and reversed phase liquid chromatography (RP-HPLC) coupled to high resolution ion trap/time-of-flight mass spectrometry (2D-HPSEC×LC-IT-TOF MS) with positive and negative modes of electrospray ionization method. Separation and characterization the allergic polymerized impurities in β-lactam antibiotics were on the basis of column-switching technique which effectively combined the advantages of HPSEC and the ability of RP-HPLC to identify the special impurities. In the first dimension HPSEC, the column was Xtimate SEC-120 analytical column (7.8mm×30cm, 5μm), and the gradient elution used pH 7.0 buffer-acetonitrile as mobile phase And the second dimension analytical column was ZORBAX SB-C18 (4.6×150mm, 3.5μm) with ammonium formate solution (10mM) and ammonium formate (8mM) in [acetonitrile-water (4:1, v/v)] solution as mobile phase. Structures of eleven unknown impurities were deduced based on the high resolution MS data with both positive and negative modes, in which nine impurities were polymerized impurities. The forming mechanism of β-lactam antibiotic polymerization in cephalosporins was also studied. The question on incompatibility between non-volatile salt mobile phase and mass spectrometry was solved completely by multidimensional heart-cutting approaches and online demineralization technique, which was worthy of widespread use and application for the advantages of stability and repeatability.
采用无捕集二维高效尺寸排阻色谱（HPSEC）和反相液相色谱（RP-HPLC）与高分辨率离子阱/飞行时间质谱联用（2D-HPSEC×LC-IT-TOF MS），并结合电喷雾电离法的正、负离子模式，对头孢地嗪、头孢甲肟和头孢尼西中的11种未知过敏杂质进行了分离和表征。基于柱切换技术对β-内酰胺类抗生素中的过敏聚合杂质进行分离和表征，该技术有效地结合了HPSEC的优势和RP-HPLC识别特殊杂质的能力。在第一维HPSEC中，色谱柱为Xtimate SEC-120分析柱（7.8mm×30cm，5μm），梯度洗脱采用pH 7.0缓冲液-乙腈作为流动相；第二维分析柱为ZORBAX SB-C18（4.6×150mm，3.5μm），以甲酸铵溶液（10mM）和甲酸铵（8mM）的[乙腈-水（4:1，v/v）]溶液作为流动相。根据正、负离子模式的高分辨率质谱数据推导了11种未知杂质的结构，其中9种杂质为聚合杂质。还研究了头孢菌素中β-内酰胺抗生素聚合的形成机制。通过多维中心切割方法和在线脱盐技术，完全解决了非挥发性盐流动相与质谱之间的不兼容性问题，该方法具有稳定性和重复性的优点，值得广泛应用。
