Research Article An Enhanced GC/MS Procedure for the Identification of Proteins in Paint Microsamples D. Fico , 1 E. Margapoti , 2 A. Pennetta , 1 and G. E. De Benedetto 1,2 1 Laboratorio di Spettrometria di Massa Analitica ed Isotopica, Dipartimento di Beni Culturali, Universit` a del Salento, 73100 Lecce, Italy 2 IBAM-CNR, Sede di Lecce, Via per Monteroni, 73100 Lecce, Italy CorrespondenceshouldbeaddressedtoA.Pennetta;antonio.pennetta@unisalento.it Received 28 August 2017; Revised 30 November 2017; Accepted 22 January 2018; Published 1 April 2018 AcademicEditor:ErwinRosenberg Copyright©2018D.Ficoetal.isisanopenaccessarticledistributedundertheCreativeCommonsAttributionLicense,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. echemicalcharacterizationofmaterialsusedinworksofartisextremelyusefulforgainingabetterknowledgeoftheartistic heritageandtoguaranteeitspreservation.AderivatizationGC/MSprocedurefortheidentificationofproteinsinamicrosample frompaintedworksofarthasbeenoptimized.eaminoacidfractionisderivatizedusinganhydrousdimethylformamide(DMF) assolventinsteadofpyridine(Py),commonlyusedtofacilitatethereaction.Althoughpyridineisoftenconsideredasilylation catalyst,therearemanyinstancesinwhichsilylationreactionsactuallyareslowerinpyridinethanothersolvents.Inaddition, pyridine also may have other undesirable effects such as the promotion of secondary products and other chromatographic anomalies.UsingDMF,theformationofartifactsislimitedandthederivatizationyieldofhydrophilicaminoacidssuchasproline andhydroxyprolinehasimproved,thusmakingtheidentificationoforganicpaintmediamorestraightforward.emethodhas been validated and successfully applied to identify the binder of the sample taken from the pictorial cycle of the 12th century monastery of Santa Maria delle Cerrate (Lecce, Italy), thus highlighting the use of eggs as a binding medium. 1. Introduction Proteinaceouspaintmedia,especiallythosebasedoneggand milk, have been used over the centuries by painters, due to excellent optical features and stability of the paint films ob- tained[1,2].echemicalcharacterizationofmaterialsusedis extremely useful for surveying historical treatments and for gainingabetterknowledgeoftheartisticheritage.isstudy entails investigating the original constituent materials and thosebecomeanintegralpartoftheworkofartitselfasaneffect ofagingandrestorations.Assessingthestateofconservationof a painting is fundamental when choosing a conservative strategy based on both prevention and intervention. De- velopinganalyticaltechniquesforunderstandingthechemical composition of painting materials and for studying the deg- radationprocessisthusofgreatimportance. In the conservation of paintings, a special care and at- tentiontoorganicmaterialsisnecessary,duetotheirrelatively increased tendency to undergo degradation, transformation, andoxidationprocess[2].Infact,thepaintlayersmayexhibit cracking, darkening, yellowing, and loss of stability and co- hesion.Milkorcasein,animalglue,egg,dryingoils(walnut, linseed, and poppy seed oils), plant resins (e.g., sandarac, mastic,andcolophony),animalresins,andwaxesarethemost common organic materials historically used in the Mediter- ranean area and in Europe. e chemical composition and physical properties of these organic materials (mixtures of organic species consisting of proteins, triglycerides, terpene compounds,sterols,esters,alcohols,hydrocarbons,freeacid, etc.) are considerably influenced by environment and aging [1,2].Awiderangeofnaturalandsyntheticorganicmaterials was used for consolidation and restoration [1]. Organic ma- terialswereusedasbinderstodispersepigmentsandtoapply themonallthesupports,therebygeneratinganadherentand elasticfilm.Proteinaceousmaterialswerethusemployedinthe temperatechnique,dryingoilintheoiltechnique,andbeeswax in encaustic painting [1, 2]. e precise study of organic materials in cultural heritage works was investigated on Hindawi Journal of Analytical Methods in Chemistry Volume 2018, Article ID 6032084, 8 pages https://doi.org/10.1155/2018/6032084