Przybilla L, Brand JD, Yoshimura K, Rader HJ, Mullen K
Max-Planck-Institut fur Polymerforschung, Mainz, Germany.
Anal Chem. 2000 Oct 1;72(19):4591-7. doi: 10.1021/ac000372q.
The insolubility of giant polycyclic aromatic hydrocarbons (PAHs) prevents their characterization by conventional analytical methods, which require a solubilization of the analyte. Laser desorption mass spectrometry may be used to analyze insoluble samples but is limited to relatively low molecular weights (approximately 2000), in the case of PAHs. To overcome this limitation, we applied MALDI-TOF mass spectrometry. Since MALDI sample preparation also requires solubility of analyte and matrix molecules, the sample preparation needed modification. The giant PAHs (>2000 Da) were investigated after using a new sample preparation, consisting of mechanically mixing analyte and matrix without any solubilization procedures. This solvent-free process allows insoluble compounds to be characterized. Furthermore, new organic molecules can be used as a matrix. Indeed, 7,7,8,8-tetracyanoquinodimethane, a new matrix with promising properties, has proven to be particularly suitable for the measurement of PAHs. Thanks to the successful characterization with MALDI-TOF mass spectrometry, the chemical design of giant PAHs, which was hindered until now for a lack of analytical methods, can now continue to develop.
巨型多环芳烃（PAHs）的不溶性使得它们无法通过传统分析方法进行表征，因为传统方法需要将分析物溶解。激光解吸质谱法可用于分析不溶性样品，但对于PAHs而言，其仅限于相对较低的分子量（约2000）。为克服这一限制，我们应用了基质辅助激光解吸电离飞行时间质谱法（MALDI-TOF质谱法）。由于MALDI样品制备也需要分析物和基质分子具有溶解性，因此样品制备需要改进。在采用一种新的样品制备方法后，对巨型PAHs（>2000 Da）进行了研究，该方法包括在不进行任何溶解程序的情况下将分析物和基质机械混合。这种无溶剂过程使得不溶性化合物能够得到表征。此外，新的有机分子可作为基质。事实上，7,7,8,8-四氰基对苯二醌二甲烷，一种具有良好性能的新型基质，已被证明特别适合于PAHs的测量。由于通过MALDI-TOF质谱法成功实现了表征，巨型PAHs的化学设计此前因缺乏分析方法而受阻，现在可以继续发展了。
