Contents lists available at ScienceDirect Applied Clay Science journal homepage: www.elsevier.com/locate/clay Note Electrochemical discrimination of manufacturing types of pottery from Magna Mater Temple and Fora of Nerva and Caesar (Rome, Italy) Francesca Di Turo a , Noemí Montoya b , Joan Piquero-Cilla b , Caterina De Vito a , Fulvio Coletti c , Ilaria De Luca c , Antonio Doménech-Carbó b, ⁎ a Department of Earth Sciences, Sapienza University of Rome, P.le Aldo Moro 5, Rome, Italy b Departament de Química Analítica, Universitat de València, Dr. Moliner, 50, 46100 Burjassot, València, Spain c Soprintendenza Speciale per il Colosseo, il Museo Nazionale Romano e l'Area Archeologica di Roma, P.zza dei Cinquecento 67, Rome, Italy ARTICLE INFO Keywords: Pottery Solid state voltammetry Electrochemical impedance spectroscopy Archaeometry ABSTRACT The voltammetry of immobilized microparticles (VIMP) methodology is applied to a series of pottery samples from the Roman sites of Nerva's Forum (second half of 9th-early 11th A.D), Caesar's Forum (second half of 9th- early 11th A.D) and Magna Mater Temple (III century). The VIMP sampling applied to voltammetric and elec- trochemical impedance spectroscopy (EIS) measurements was applied by the first time to acquire archaeometric information on archaeological pottery. VIMP measurements using pressed sample pellets on gold electrodes in contact with air-saturated 0.10 M H 2 SO 4 have permitted to detect voltammetric signals for the reduction/oxi- dation of Fe and Mn minerals as well as catalytic effects the mineral components on gold oxidation and oxygen reduction reaction. A consistent sample grouping was obtained using independent EIS measurements performed on microparticulate deposits of pottery samples on graphite electrodes in the same electrolyte. 1. Introduction Ceramic materials are of great importance in the archaeological science as far as each population, over the centuries, has developed specific production technology depending on the knowledge and sources of raw materials (Towe, 1999). Archeologists usually dis- criminate potteries according to the morphology, style and the dec- oration of the pottery (Aruga et al., 1993) while the characterization of the materials had helped the knowledge about production technologies, raw materials used and provenance (Gomez et al., 2002; Rathossi et al., 2004; Chatfield, 2010; Andaloro et al., 2011; Kramar et al., 2012). Moreover, ceramics can be considered as chronological indicators car- rying out information about the archaeological context (Medeghini et al., 2014). Accordingly, the discrimination between different pottery types is of archaeometric interest, but this aim is frequently made dif- ficult by the fragmentation of the objects and their appearance in ill- defined archaeological contexts. There are several factors that influence the production of pottery in the ancient times: temperature, reducing or oxidant atmosphere in the furnace, duration of the firing, crystallization of neoformed minerals as well as the skills of the artisan (De Benedetto et al., 2002). Pottery is usually characterized by means of elemental analysis, accompanied by thermal analysis, X-ray diffraction, Raman spectroscopy, SEM-EDS, FTIR, (Mangueira et al., 2013, 2016), as well as neutron and synchro- tron radiation-based techniques (Bennington, 2004; Botti et al., 2006; Barone et al., 2011), usually combined in multi-technique approaches (Maltoni et al., 2012; Grifa et al., 2013;De Vito et al., 2014; Medeghini et al., 2014). Several of available techniques, however, involve the use of interdepartmental equipments, thus limiting their practical use for routine analysis when large number of objects is recovered from the archaeological sites, a common demand of archeologists, conservators and restorers. In the current report, we present a methodology aimed to comple- ment the existing techniques for pottery grouping of application in routine analysis and even for in-field analysis. This is based on the voltammetry of microparticles (VIMP), a technique developed by Scholz et al. (2014), which needs a minimally invasive sampling (Doménech-Carbó et al., 2009, 2013). The VIMP technique, previously used for characterizing different iron and manganese compounds in ceramic materials (Doménech-Carbó et al.,2001 & 2002; Sánchez- Ramos et al., 2002) and for discriminating the production centers of archaeological lead silicate glasses (Doménech-Carbó et al., 2016), has been used here for the first time to discriminate pottery samples. In order to validate the proposed electrochemical methodology, the study was applied to a series of samples coming from the Caesar's Forum in Rome (second half of 9th-early 11th A.D.) which were previously https://doi.org/10.1016/j.clay.2018.06.024 Received 9 May 2018; Received in revised form 14 June 2018; Accepted 16 June 2018 ⁎ Corresponding author. E-mail address: antonio.domenech@uv.es (A. Doménech-Carbó). Applied Clay Science 162 (2018) 305–310 0169-1317/ © 2018 Published by Elsevier B.V. T