title: Dihydrobenzoic acid modified nanoparticle as a MALDI-TOF MS matrix for soft ionization and structure determination of small molecules with diverse structures.
abstract: Efficient structural characterization is important for quality control when developing novel materials. In this study, we demonstrated the soft ionization capability of the hybrid of immobilized silica and 2,5-dihydrobenzoic acid (DHB) on iron oxide magnetic nanoparticles in MALDI-TOF MS with a clean background. The ratio between SiO(2) and DHB was examined and was found to affect the surface immobilization of DHB on the nanoparticle, critically controlling the ionization efficiency and interference background. Compared with commercial DHB, the functionalized nanoparticle-assisted MALDI-TOF MS provided superior soft ionization with production of strong molecular ions within 5 ppm mass accuracy on a variety of new types of synthetic materials used for solar cells, light emitting devices, dendrimers, and glycolipids, including analytes with either thermally labile structures or poor protonation tendencies. In addition, the enhancements of the molecular ion signal also provided high-quality product-ion spectra allowing structural characterization and unambiguous small molecule identification. Using this technique, the structural differences among the isomers were distinguished through their characteristic fragment ions and comprehensive fragmentation patterns. With the advantages of long-term stability and simple sample preparation by deposition on a regular sample plate, the use of DHB-functionalized nanoparticles combined with high-resolution MALDI-TOF MS provides a generic platform for rapid and unambiguous structure determination of small molecules.
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei, Taiwan.
authors.forename: Mei-Chun
authors.initials: MC
authors.lastname: Tseng
authors.forename: Rofeamor
authors.initials: R
authors.lastname: Obena
authors.forename: Ying-Wei
authors.initials: YW
authors.lastname: Lu
authors.forename: Po-Chiao
authors.initials: PC
authors.lastname: Lin
authors.forename: Ping-Yu
authors.initials: PY
authors.lastname: Lin
authors.forename: Yung-Sheng
authors.initials: YS
authors.lastname: Yen
authors.forename: Jiann-Tsuen
authors.initials: JT
authors.lastname: Lin
authors.forename: Li-De
authors.initials: LD
authors.lastname: Huang
authors.forename: Kuang-Lieh
authors.initials: KL
authors.lastname: Lu
authors.forename: Long-Li
authors.initials: LL
authors.lastname: Lai
authors.forename: Chun-Cheng
authors.initials: CC
authors.lastname: Lin
authors.forename: Yu-Ju
authors.initials: YJ
authors.lastname: Chen
mesh_terms: D000390:Air Ionization; D001565:Benzoates / Q000737:chemistry*; D016208:Databases, Factual; D006017:Glycolipids / Q000737:chemistry; D007287:Inorganic Chemicals / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D001565:Benzoates; D006017:Glycolipids; D007287:Inorganic Chemicals; D007477:Ions; D058185:Magnetite Nanoparticles; D009930:Organic Chemicals; D012822:Silicon Dioxide