121st General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Analytical Chemists I
Room No. Room 201A
Time THU 10:39-:
Code ANAL1.O-15
Subject Large-area Graphene Films as Engaging Target Surfaces for Highly Reproducible Matrix-assisted Laser Desorption Ionization for Quantitative Mass Spectrometry
Authors YOONKYUNG CHOI, Sang Yun Han*
Department of Nano Chemistry, Gachon University Global Campus, Korea
Abstract Matrix-assisted laser desorption ionization (MALDI) mass spectrometry is a powerful means for characterization of large and complex molecules. However, due to the sweet spot issues that intrinsically arise from inhomogeneous matrix-analyte crystals utilized as MALDI samples, its reproducibility in ion generation and thus its applications for quantification have been rather limited. In this letter, we demonstrate a simple strategy to improve uniformity of matrix-analyte crystal spots, which was realized by adapting non-inert, interacting surfaces on purpose for the first time, i.e. large-area graphene films in this study, as target surfaces. The graphitic surfaces of graphene films may interact with excessive matrix molecules during the sample drying process, which induces apparently uniform crystallization of MALDI sample spots on the surfaces. Furthermore, high-resolution mass spectrometric imaging revealed that analytes embedded in the crystals formed on the graphene films were more evenly distributed over a MALDI sample spot than those commonly produced on the metal target plates, which as a result greatly suppresses appearance of sweet spots. In virtue of improved uniformity of MALDI sample spots, this method showed good linear responses of ion intensity to analyte concentrations (R2 > 0.99) as well as small fluctuations (s < 10%), which would be applicable for quantitative mass spectrometry using the MALDI method.
E-mail choiyk5@naver.com