title: MALDI-TOF MS Imaging evidences spatial differences in the degradation of solid polycaprolactone diol in water under aerobic and denitrifying conditions.
abstract: Degradation of solid polymers in the aquatic environment encompasses a variety of biotic and abiotic processes giving rise to heterogeneous patterns across the surface of the material, which cannot be investigated using conventional Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) that only renders an "average" picture of the sample. In that context, MALDI-TOF MS Imaging (MALDI MSI) provides a rapid and efficient tool to study 2D spatial changes occurred in the chemical composition of the polymer surface. Commercial polycaprolactone diol (average molecular weight of 1250Da) was selected as test material because it had been previously known to be amenable to biological degradation. The test oligomer probe was incubated under aerobic and denitrifying conditions using synthetic water and denitrifying mixed liquor obtained from a wastewater treatment plant respectively. After ca. seven days of exposure the mass spectra obtained by MALDI MSI showed the occurrence of chemical modifications in the sample surface. Observed heterogeneity across the probe's surface indicated significant degradation and suggested the contribution of biotic processes. The results were investigated using different image processing tools. Major changes on the oligomer surface were observed when exposed to denitrifying conditions.
authors.affiliation: IDAEA-CSIC, Institute of Environmental Assessment and Water Research, C/Jordi Girona, 18-26, 08034 Barcelona, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rivas
authors.affiliation: IDAEA-CSIC, Institute of Environmental Assessment and Water Research, C/Jordi Girona, 18-26, 08034 Barcelona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Ginebreda
authors.affiliation: IDAEA-CSIC, Institute of Environmental Assessment and Water Research, C/Jordi Girona, 18-26, 08034 Barcelona, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Pérez
authors.affiliation: IQAC-CSIC, Institute of Advanced Chemistry of Catalonia, C/Jordi Girona, 18-26, 08034 Barcelona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Quero
authors.affiliation: IDAEA-CSIC, Institute of Environmental Assessment and Water Research, C/Jordi Girona, 18-26, 08034 Barcelona, Spain; ICRA, Catalan Institute for Water Research, Scientific and Technologic Park of the UdG, Emili Grahit, 101-17003 Girona, Spain.
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
mesh_terms: D000332:Aerobiosis; D058440:Denitrification; D004784:Environmental Monitoring / Q000379:methods*; D006018:Glycols / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D006018:Glycols; D011091:Polyesters; D014874:Water Pollutants, Chemical; C016240:polycaprolactone
keywords: Aerobic; Degradation; Denitrifying; Imaging; MALDI; Polymer