Multivariate Analysis of MALDI Imaging Mass Spectrometry Data of Mixtures of Single Pollen Grains

  • Franziska Lauer
  • Sabrina Diehn
  • Stephan Seifert
  • Janina Kneipp
  • Volker Sauerland
  • Cesar Barahona
  • Steffen WeidnerEmail author
Research Article


Mixtures of pollen grains of three different species (Corylus avellana, Alnus cordata, and Pinus sylvestris) were investigated by matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF imaging MS). The amount of pollen grains was reduced stepwise from > 10 to single pollen grains. For sample pretreatment, we modified a previously applied approach, where any additional extraction steps were omitted. Our results show that characteristic pollen MALDI mass spectra can be obtained from a single pollen grain, which is the prerequisite for a reliable pollen classification in practical applications. MALDI imaging of laterally resolved pollen grains provides additional information by reducing the complexity of the MS spectra of mixtures, where frequently peak discrimination is observed. Combined with multivariate statistical analyses, such as principal component analysis (PCA), our approach offers the chance for a fast and reliable identification of individual pollen grains by mass spectrometry.

Graphical Abstract


MALDI imaging MS Pollen grains Multivariate statistics Hierarchical cluster analysis Principal component analysis 



The authors thank Thomas Dürbye of the Botanic Garden and Botanical Museum Berlin-Dahlem for their support in sample collection.

Funding Information

Janina Kneipp received funding from the European Research Council (ERC) (grant no. 259432).

Supplementary material

13361_2018_2036_MOESM1_ESM.docx (3.4 mb)
ESM 1 (DOCX 3447 kb)


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Copyright information

© American Society for Mass Spectrometry 2018

Authors and Affiliations

  1. 1.Bundesanstalt für Materialforschung und-prüfung (BAM)BerlinGermany
  2. 2.Humboldt-Universität zu BerlinBerlinGermany
  3. 3.Bruker Daltonik GmbHBremenGermany

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