Laboratory of Glycobiology, The Noguchi Institute, 1-8-1 Kaga, Itabashi, Tokyo 173-0003, Japan.
Rapid Commun Mass Spectrom. 2009 Dec;23(23):3787-94. doi: 10.1002/rcm.4320.
A sample preparation method that is suitable for sensitive detection of underivatized oligosaccharides by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been investigated. As compared with the conventional dried-droplet or ethanol (EtOH) recrystallization method, superior mass spectra in terms of ion yield and signal-to-noise (s/n) ratio were obtained when methanol (MeOH) was used as a solvent for the mixture of matrix and oligosaccharides. Based on these results, a new sample preparation method, named the 'reverse thin layer method', was developed. This method comprises two steps: first, complete drying of the oligosaccharide solution on the MALDI target plate; and second, deposition of the matrix dissolved in a small amount of MeOH. Using this method, a relatively homogeneous matrix crystal was generated and higher yields of both positive and negative ions were obtained from oligosaccharides compared with conventional methods. Notably, the method can be applied to various matrices including both solid and liquid matrices.
研究了一种适用于基质辅助激光解吸/电离质谱（MALDI-MS）对未衍生寡糖进行灵敏检测的样品制备方法。与传统的干液滴或乙醇（EtOH）重结晶方法相比，当甲醇（MeOH）用作基质和寡糖混合物的溶剂时，可获得在离子产率和信噪比（s/n）方面具有优势的质谱。基于这些结果，开发了一种新的样品制备方法，称为“反薄层法”。该方法包括两个步骤：首先，将寡糖溶液完全干燥在 MALDI 靶板上；其次，将溶解在少量 MeOH 中的基质沉积。使用该方法，可以生成相对均匀的基质晶体，并且与传统方法相比，从寡糖中获得了更高的正离子和负离子产率。值得注意的是，该方法可应用于各种基质，包括固体和液体基质。
