Phosphatidylcholines and -ethanolamines can be easily mistaken in phospholipid mixtures: a negative ion MALDI-TOF MS study with 9-aminoacridine as matrix and egg yolk as selected example

A combination of electrochemistry (EC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (off-line EC-MALDI-TOF-MS) was applied for determination of the studied biologically active compounds (D-glucose, D-fructose, D-galactose, D-pinitol, L-chiro-inositol, and myo-inositol) and their possible electrochemical metabolites. In this work, boron-doped diamond electrode (BDD) was used as a working electrode. MALDI-TOF-MS experiments were carried out (both in positive and negative ion modes and using two matrices) to identify the structures of electrochemical products. This was one of the first applications of the EC system for the generation of electrochemical products produced from saccharides and cyclitols. Moreover, exploratory data analysis approaches (correlation networks, hierarchical cluster analysis, weighted plots) were used in order to present differences/similarities between the obtained spectra, regarding the class of analyzed compounds, ionization modes, and used matrices. This work presents the investigation and comparison of fragmentation patterns of sugars, cyclitols, and their respective products generated through the electrochemistry (EC) process.

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Detection of Adducts with Matrix Clusters in the Positive and Negative Ion Mode MALDI-TOF Mass Spectra of Phospholipids

Zeitschrift für Naturforschung B ◽

10.1515/znb-2009-0314 ◽

2009 ◽

Vol 64 (3) ◽

pp. 331-334 ◽

Cited By ~ 9

Author(s):

Marijana Petković ◽

Jürgen Schiller ◽

Matthias Müller ◽

Rosmarie Süß ◽

Klaus Arnold ◽

...

Keyword(s):

Mass Spectra ◽

Negative Ion ◽

Dihydroxybenzoic Acid ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Maldi Tof Mass Spectra ◽

Negative Ion Mode ◽

Charged Ions ◽

Positively Charged ◽

Tof Ms

It is usually accepted that neutral phospholipids (PLs) generate singly positively charged ions, whereas negative PLs are easily detectable in the negative ion mode when analysed by matrix-assisted laser desorption and ionisation time-offlight mass spectrometry (MALDI-TOF MS). In this study, we demonstrate that some caution is required in the interpretation of MALDI-TOF mass spectra of PLs, since also neutral PLs have appeared to be detectable in the negative ion mode as well. Neutral and negatively charged phospholipids can generate adducts with the most commonly used matrix - 2,5-dihydroxybenzoic acid - yielding singly negatively charged ions that are detectable in the spectra. This further contributes to the complexity of the spectra and potentially leads to severe misinterpretation, particularly when unknown mixtures of PLs are analysed by MALDI-TOF MS.

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Investigation of MALDI-TOF Mass Spectrometry of Diverse Synthetic Metalloporphyrins, Phthalocyanines and Multiporphyrin Arrays

Journal of Porphyrins and Phthalocyanines ◽

10.1002/(sici)1099-1409(199904)3:4<283::aid-jpp132>3.0.co;2-f ◽

1999 ◽

Vol 03 (04) ◽

pp. 283-291 ◽

Cited By ~ 94

Author(s):

N. SRINIVASAN ◽

CAROL A. HANEY ◽

JONATHAN S. LINDSEY ◽

WENZHU ZHANG ◽

BRIAN T. CHAIT

Keyword(s):

Mass Spectrometry ◽

Negative Ion ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Flight Mass Spectrometry ◽

Powerful Analytical Tool ◽

Molecular Masses ◽

Dominant Process ◽

Tof Ms

We investigated the utility of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for analyzing porphyrinic compounds using a variety of different synthetic porphyrins, azaporphyrins, phthalocyanines and multiporphyrin arrays. Comparisons of spectra obtained from these analytes deposited either as neat samples or codeposited with neutral or acidic matrices have been made with the goal of identifying conditions that yield minimal demetalation, transmetalation, adduct formation and fragmentation. It was found that the molecular masses of many porphyrins can be successfully measured from neat sample preparations and do not require a matrix to facilitate desorption and ionization, although the measurement of large multiporphyrin arrays was facilitated by the use of matrices. Demetalation of magnesium porphyrins occurred in the presence of acidic matrices, but not with neutral matrices such as 1,4-benzoquinone. Positive ion spectra were obtained for each compound and negative ion spectra were also collected for the azaporphyrins and phthalocyanines. Examination of selected samples (prepared neat, with 1,4-benzoquinone, 2,3,5,6-tetrachloro-1,4-benzoquinone or α-cyano-4-hydroxycinnamic acid) showed that the dominant process of ionization involved oxidation yielding the radical cation M+· rather than the protonated molecule [M+H]+. MALDI-TOF-MS is shown to be a powerful analytical tool for the characterization of diverse synthetic porphyrinic compounds.

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Negative ion MALDI-TOF MS, ISD and PSD of neutral underivatized oligosaccharides without anionic dopant strategies, using 2,5-DHAP as a matrix

Journal of Mass Spectrometry ◽

10.1002/jms.3727 ◽

2016 ◽

Vol 51 (2) ◽

pp. 111-122 ◽

Cited By ~ 7

Author(s):

Marko Jovanović ◽

Jasna Peter-Katalinić

Keyword(s):

Negative Ion ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Tof Ms

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Characterization of galactosyl and lactosyl sulfatide species in human serum by MALDI-TOF mass spectrometry

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/0004563219849077 ◽

2019 ◽

Vol 56 (5) ◽

pp. 574-582

Author(s):

Atsushi Hori ◽

Makoto Yamaura ◽

Sunao Morita ◽

Takeshi Uehara ◽

Takayuki Honda ◽

...

Keyword(s):

Mass Spectrometry ◽

Fatty Acids ◽

Human Serum ◽

Negative Ion ◽

Simple Method ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Flight Mass Spectrometry ◽

Sugar Chains ◽

Tof Ms

Background Sulfatides are found in a variety of tissues and serum lipoproteins. Sulfatide is a molecular species composed of various sphingoid bases, fatty acids and sugar chains; therefore, rapid analysis of the qualitative structure is important in clinical assessment. Methods In this study, sulfatide-rich fractions were isolated from serum lipids, and the sulfatide species were analysed by negative ion mode using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results Sulfatide species identified in human serum included two different sugar chains, eight sphingoid molecules and various fatty acid side chains including hydroxy fatty acids. In total, 64 galactosyl sulfatides (SM4s) and 49 lactosyl sulfatides (SM3) were identified. Quantitatively, the amount of SM3 was less than 1% of the amount of SM4s. The fatty acids of SM4s of healthy serum ( n = 8) were predominantly C16:0 and a hydroxylation C16:0 (C16:0h), followed by very long chain fatty acids (VLCFAs) predominant species, and SM3 was a major component of VLCFAs. Conclusion This present study described a simple method of human serum sulfatide analysis using MALDI-TOF MS. This method is suitable for clinical laboratories and is likely to increase the understanding of the roles of sulfatide species in both physiological and disease states.

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DBDA as a Novel Matrix for the Analyses of Small Molecules and Quantification of Fatty Acids by Negative Ion MALDI-TOF MS

Journal of the American Society for Mass Spectrometry ◽

10.1007/s13361-017-1881-y ◽

2018 ◽

Vol 29 (4) ◽

pp. 704-710 ◽

Cited By ~ 4

Author(s):

Ling Ling ◽

Ying Li ◽

Sheng Wang ◽

Liming Guo ◽

Chunsheng Xiao ◽

...

Keyword(s):

Fatty Acids ◽

Small Molecules ◽

Negative Ion ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Tof Ms

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Enhanced MALDI-TOF MS Analysis of Phosphopeptides Using an Optimized DHAP/DAHC Matrix

Journal of Biomedicine and Biotechnology ◽

10.1155/2010/759690 ◽

2010 ◽

Vol 2010 ◽

pp. 1-12 ◽

Cited By ~ 3

Author(s):

Junjie Hou ◽

Zhensheng Xie ◽

Peng Xue ◽

Ziyou Cui ◽

Xiulan Chen ◽

...

Keyword(s):

Effective Means ◽

Negative Ion ◽

Phosphorylation Sites ◽

Measurement Sensitivity ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Flight Mass Spectrometry ◽

Phosphorylated Peptides ◽

Negative Ion Mode ◽

Tof Ms

Selecting an appropriate matrix solution is one of the most effective means of increasing the ionization efficiency of phosphopeptides in matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In this study, we systematically assessed matrix combinations of 2, 6-dihydroxyacetophenone (DHAP) and diammonium hydrogen citrate (DAHC), and demonstrated that the low ratio DHAP/DAHC matrix was more effective in enhancing the ionization of phosphopeptides. Low femtomole level of phosphopeptides from the tryptic digests ofα-casein andβ-casein was readily detected by MALDI-TOF-MS in both positive and negative ion mode without desalination or phosphopeptide enrichment. Compared with the DHB/PA matrix, the optimized DHAP/DAHC matrix yielded superior sample homogeneity and higher phosphopeptide measurement sensitivity, particularly when multiple phosphorylated peptides were assessed. Finally, the DHAP/DAHC matrix was applied to identify phosphorylation sites fromα-casein andβ-casein and to characterize two phosphorylation sites from the human histone H1 treated with Cyclin-Dependent Kinase-1 (CDK1) by MALDI-TOF/TOF MS.

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