Surface Mass Spectrometry of Two Component Drug鈥揚olymer Systems: Novel Chromatographic Separation Method Using Gentle-Secondary Ion Mass Spectrometry (G-SIMS)

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• 作者：Ryosuke Ogaki ; Ian S. Gilmore ; Morgan R. Alexander ; Felicia M. Green ; Martyn C. Davies ; Joanna L. S. Lee
• 刊名：Analytical Chemistry
• 出版年：2011
• 出版时间：May 15, 2011
• 年：2011
• 卷：83
• 期：10
• 页码：3627-3631
• 全文大小：777K
• 年卷期：v.83,no.10(May 15, 2011)
• ISSN：1520-6882

文摘

In recent years, there has been an increase in the use of time-of-flight secondary ion mass spectrometry (TOF-SIMS) for characterizing material surfaces. A great advantage of SIMS is that the analysis is direct and has excellent spatial resolution approaching a few hundred nanometers. However, the lack of the usual separation methods in mass spectrometry such as chromatography or ion mobility combined with the complexity of the heavily fragmented ions in the spectra means that the interpretation of multicomponent spectra in SIMS is very challenging indeed. The requirements for high-definition imaging, with say 256 脳 256 pixels, in around 10 min analysis time places significant constraints on the instrument design so that separation using methods such as ion mobility with flight times of milliseconds are incompatible. Clearly, traditional liquid and gas chromatographies are not at all possible. Previously, we developed a method known as Gentle-SIMS (G-SIMS) that simplifies SIMS spectra so that the dominant ions are simply related to the structure of the substances analyzed. The method uses a measurement of the fragmentation behavior under two different primary ion source conditions and a control parameter known as the g-index. Here, we show that this method may be used 鈥渃hromatographically鈥?to separate the mass spectra of a drug molecule from the matrix polymer. The method may be used in real-time and is directly compatible with the majority of TOF-SIMS instruments. The applicability to other imaging mass spectrometeries is discussed.