This work was supported by Portuguese Foundation for Science and Technology: Ciência 2007 Program and IF Development Grant (IF/00111/2013) to A.J.S., Ph.D. scholarships to S.I.A. (SFRH/BD/81495/ 2011); Canada Research Chair in Biomedical Engineering (LAB). This article has been developed under the scope of the project NORTE-01-0145-FEDER-000013 and NORTE-01-0145-FEDER-000023, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work has been funded by FEDER funds, through the Competitiveness Factors OperationaUnion (FEDER), and by the National Mass Spectrometry Network under the contract REDE/1506/REM/2005.l Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the projects POCI-01-0145-FEDER- 007038, PTDC/NEU-NMC/0205/2012, UID/NEU/04539/2013, and POCI-01-0145-FEDER-007440 cofunded by the Programa Operacional Factores de Competitividade, QREN, the European