Anal Bioanal Chem (2007) 387:193–204 DOI 10.1007/s00216-006-0905-4
REVIEW
Recent developments in methods and technology for analysis of biological samples by MALDI-TOF-MS Chensong Pan & Songyun Xu & Houjiang Zhou & Yu Fu & Mingliang Ye & Hanfa Zou
Received: 24 July 2006 / Revised: 28 September 2006 / Accepted: 29 September 2006 / Published online: 4 November 2006 # Springer-Verlag 2006
Abstract Matrix-assisted laser desorption/ionization–timeof-flight mass spectrometry (MALDI-TOF-MS) is widely used in a variety of fields because it has the characteristics of speed, ease of use, high sensitivity, and wide detectable mass range for obtaining molecular weights and for structural characterization of macromolecules. In this article we summarize recent developments in matrix additives, new matrices, and sample-pretreatment methods using offprobe or on-probe techniques or nanomaterials for MALDITOF-MS analysis of biological samples. Keywords Review . MALDI . Sample pretreatment . Matrix . Nanomaterials Abbreviations MALDI-TOFMS DIOS SELDI SAM IMAC CHCA 2,4,6-THAP 2,5-DHB CTAB DABP
matrix-assisted laser desorption ionization time-of-flight mass spectrometry desorption ionization on porous silicon surface-enhanced laser desorption ionization self-assembled monolayer immobilized metal ion-affinity chromatography α-Cyano-4-hydroxycinnamic acid 2,4,6-Trihydroxyacetophenone 2,5-Dihydroxybenzoic acid cetriamonium bromide 3,4-Diaminobenzophenone
C. Pan : S. Xu : H. Zhou : Y. Fu : M. Ye : H. Zou (*) National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China e-mail:
[email protected]
ILs SCX SPE BAEE
ionic liquids strong cation exchange solid-phase extraction Nα-Benzoyl-L-arginine ethyl ester hydrochloride
Introduction Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a powerful tool in a variety of fields [1–6] because it enables molecularweight determination and structural characterization of macromolecules with the characteristics of speed, ease of use, high sensitivity, and wide detectable mass range. Because of its tolerance of small amounts of contaminants such as salts and surfactants, MALDI-MS can usually meet requirements for analysis of biological samples without pretreatment, although large amounts of such contaminants will reduce or suppress the ion signal of the analytes and seriously degrade the quality of mass spectra. There are, however, still some practical problems in the application of this popular technique. One critical problem is that the suppression effects between analyte molecules still frequently arise during MALDI analysis, especially in the analysis of the mixtures. The probability of signal suppression effects increases with increased analyte complexity, and sample pretreatment then becomes essential for analysis of trace components in mixtures such as biological samples. In addition, because of the unavoidable presence of sodium and potassium in the sample solution, cation adduct clusters are commonly detected in MALDI-MS spectra; these reduce sensitivity by partitioning the signal intensity arising from one analyte into different adduct
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cluster peaks. Adduct clusters can also suppress the signal of an overlapping or neighboring peak of low abundance. The serious background arising from organic matrix ions also makes characterization of small molecules (
