Papers by Susana Sousa Gomes
Revista portuguesa de arqueologia, 2020
O chumbo dos sistemas hidráulicos romanos no Ocidente Peninsular: proveniência e processos metalú... more O chumbo dos sistemas hidráulicos romanos no Ocidente Peninsular: proveniência e processos metalúrgicos
Lead Isotope Composition in Archaeological Metallic Artefacts by Q-ICPMS The present study aims t... more Lead Isotope Composition in Archaeological Metallic Artefacts by Q-ICPMS The present study aims to contribute to the identification of mineral deposits used as raw source in the production of glandes plumbeae, accidentally recovered in Alto dos Cacos (Almeirim) and attributed to the Roman Period, and some bronze alloys, recovered from Fraga dos Corvos (Macedo de Cavaleiros) Bronze Age archaeological site. Therefore, methodologies to determine the lead isotope ratios in small samples taken from the archaeological metallic artefacts by quadrupole inductively coupled plasma mass spectrometry (Q-ICPMS) have been developed. The collection was composed by 24 glandes plumbeae, obtained by different manufacture processes including casting. The lead isotope ratios obtained values by sample dissolution in HNO 3 20% did not allow to establish groups having different isotopic compositions, which suggests a probable local production. Bronze alloys from Fraga dos Corvos were composed by 4 archaeological artefacts and 2 fragments of metallurgical remains. In this case, after acid dissolution with HNO 3 20%, the anodic electrochemical separation of Pb from the bronze matrix was performed. The obtained isotope ratio distribution patterns evidenced the existence of two distinct groups, which may indicate exogeneous influences and/or the use of ores with different origin In the comparative study with Iberian mineralogical deposits, significant correspondences among the Pb isotopic patterns of bronze artefacts and those of mineral deposits from Sierra Morena and Basque-Cantabria basin were observed. Lead artefacts seem to be better associated to deposits from Andalusia-Murcia and Basque-Cantabria, but also from the south of France (Cévennes and Mont-Lozére Massif) and Sardinia.
Journal of Archaeological Science: Reports, 2020
Abstract This work presents the first provenance study on copper in use by 3rd millennium BC comm... more Abstract This work presents the first provenance study on copper in use by 3rd millennium BC communities in southern Portugal. Copper ores from small mines and copper artefacts from Chalcolithic settlements were subjected to Pb isotope analysis. Some of Pb isotope ratios obtained in ores from the Ossa-Morena Zone, but also from the South Portuguese Zone, evince the existence of deposits with highly radiogenic Pb, which was previously considered rare in the Iberian Peninsula. Pb isotope ratios of artefacts were compared with Pb isotope fields of closer geological/tectonostratigraphic zones, namely the South Portuguese Zone, Ossa-Morena Zone and Central Iberian Zone. The assessment suggests that most artefacts were produced with copper from the Ossa-Morena Zone. Nevertheless, a flat axe of the Tres Moinhos settlement is a remarkable exception due to its highly radiogenic Pb signature, which only has parallels in the Iberian Peninsula on copper ores of the Chalcolithic mines of La Profunda and El Milagro (northern Spain). Consequently, this flat axe constitutes the first indication of a possible long-distance trade of copper between the Cantabrian region and southwestern Iberian Peninsula during the 3rd millennium BC.
During Roman times, lead was widely used, namely for military weapons, like leaden sling projecti... more During Roman times, lead was widely used, namely for military weapons, like leaden sling projectiles (glandes plumbeae). This work presents a preliminary study of elemental and Pb isotope analysis of 24 glandes plumbeae with different typologies accidentally discovered at Alto dos Cacos (Almeirim) and possibly related to the Roman army from Hispania Ulterior. The artefacts were analyzed by energy dispersive X ray fluorescence (EDXRF) and quadrupole based inductively coupled plasma mass spectrometry (ICP QMS). The elemental analysis indicates some trace elements in the lead matrix. The lead isotope composition analyses distinguish two groups, regardless of typologies.
Journal of Archaeological Science: Reports
In the present study, a set of 24 glandes plumbeae found at Alto dos Cacos, a Roman Republican mi... more In the present study, a set of 24 glandes plumbeae found at Alto dos Cacos, a Roman Republican military camp located in the Tagus valley, Portugal, was analysed by a quadrupole based ICP-MS to determine the tin (Sn) content and lead (Pb) isotope ratios. Results were compared with similar data previously obtained for fistulae plumbeae aquariae from Conimbriga, an important Lusitanian Roman centre during the Empire. Low Sn contents (≤0.01 wt%) were observed in 25% of glandes plumbeae indicating that were probably made with non-recycled lead. A similar situation was perceived for the set of fistulae aquariae, although most of the remaining fistulae present systematically higher Sn concentrations than those of glandes suggesting that lead recycling increased during the Empire. Pb isotope ratios distribution differentiated the analysed samples into two distinct groups: one composed by most of glandes plumbeae (15) and the other by the remaining glandes plumbeae (9) and all fistulae aquariae. The comparison with Pb isotope ratios of the published data for several lead ore deposits, exploited by the Roman in Iberian Peninsula, suggests that lead used in the manufacture of most of the glandes plumbeae would come from Linares-La Carolina, Alcudia Valley and Ossa Morena Zone. Also, some glandes could have been made using these ores, probably mixed with lead ores from Gallia Narbonensis (Southern France) or from Sardinia in the Mediterranean region. On the other hand, lead used in most fistulae aquariae came from Iberian mines, namely from Sierra Morena (Alcudia Valley and Linares-La Carolina mines) and Ossa Morena mining district, although in some cases, probably mixed with lead from the Iberian Pyrite Belt.
Microchemical Journal
Lead metal and lead artefacts were widespread over the Roman world, as consequence of its large u... more Lead metal and lead artefacts were widespread over the Roman world, as consequence of its large use in public buildings, namely as plumbing on hydraulic systems of Roman cities and villae. The determination of Pb isotope ratios combined with minor and trace element contents of such lead artefacts may constitute a powerful tool for provenance studies as well as in the assessment of trade routes during the Roman period. In the present work forty four fistulae plumbeae from the hydraulic systems installed at Conimbriga were analysed using a quadrupole based ICP-MS. The overall results demonstrate the suitableness of this well-established and economic analytical technique involving simple sample preparation and high throughput. Pb isotopic patterns present high scattered distributions which suggest different provenances of the raw material. Ag, As, Bi, Cu, Ni, Sb, and Sn contents were determined in an attempt to identify the type of raw materials and the metallurgical process used to obtain the lead metal. Sn content points to the frequent use of recycled lead. The Pb isotope ratios of samples of lead pipes made with metal probably not recycled indicate the use of raw materials (galena ores) from Sierra Morena mines or desilvered litharge resulting from silver cupellation probably using argentiferous jarosite ores from the Iberian Pyrite Belt (Rio Tinto mines).
Microchemical Journal, 2015
Most Roman hydraulic systems were made with lead plumbing manufactured by casting lead sheets whi... more Most Roman hydraulic systems were made with lead plumbing manufactured by casting lead sheets which were sealed by joining the edges with a molten metal. Modern studies suggest that the Romans used distinct techniques for joining the lead pipes (fistulae aquariae), such as welding (with lead) and soldering (with a tin-lead alloy). Micro-EDXRF and micro-PIXE analysis were used for micro-chemical characterization of joining areas of 13 water lead pipes collected in Roman archaeological contexts from Conimbriga and Augusta Emerita. Results indicate that two lead pipes from Conimbriga were sealed with a solder alloy, having a Sn content close to the eutectic point (61.9 wt.%). The remaining fistulae seals have relatively low contents of Sn and also of other elements such as Sb and Cu. Micro-analyses carried out along the pipes and welding regions show the use of lead with some impurities on both areas, while the elemental mapping of tin-lead solders show the presence of the (lead-rich) and (tin-rich) phases.
A set of bronzes recovered from Fraga dos Corvos (Macedo de Cavaleiros) archaeological site, loca... more A set of bronzes recovered from Fraga dos Corvos (Macedo de Cavaleiros) archaeological site, located in Northern Portugal, was analyzed to investigate their lead isotope ratios. The studied metallic artefacts have diverse typologies and include two bar fragments, four fibulae, a pendant and fragments of a possible cauldron. Besides these, two metallurgical remains (nodule and droplet) were also analyzed. Elemental analysis by μ-EDXRF showed that bronzes have a Sn content varying between 5.1 and 13.9% and a Pb content from 1.4 to 6.1%, which allowed to select a suitable methodology for lead separation, prior to isotope ratio determinations. In these alloys the Pb isotope determinations (204Pb, 206Pb, 207Pb and 208Pb) are influenced by matrix effects that decrease the sensitivity and the reproducibility of the measurements. Analytical procedure consisted in electrochemical Pb separation by anodic oxidation. The determination of Pb isotope ratios was made by ICP-MS with a quadrupole ma...
The present study aims to contribute to the identification of mineral deposits used as raw source... more The present study aims to contribute to the identification of mineral deposits used as raw source in the production of glandes plumbeae, accidentally recovered in Alto dos Cacos (Almeirim) and attributed to the Roman Period, and some bronze alloys, recovered from Fraga dos Corvos (Macedo de Cavaleiros) Bronze Age archaeological site. Therefore, methodologies to determine the lead isotope ratios in small samples taken from the archaeological metallic artefacts by quadrupole inductively coupled plasma mass spectrometry (Q-ICPMS) have been developed. The collection was composed by 24 glandes plumbeae, obtained by different manufacture processes including casting. The lead isotope ratios obtained values by sample dissolution in HNO3 20% did not allow to establish groups having different isotopic compositions, which suggests a probable local production. Bronze alloys from Fraga dos Corvos were composed by 4 archaeological artefacts and 2 fragments of metallurgical remains. In this case, ...
Food Additives & Contaminants: Part A, 2009
During Roman times, lead was widely used, namely for military weapons, like leaden sling projecti... more During Roman times, lead was widely used, namely for military weapons, like leaden sling projectiles (glandes plumbeae). This work presents a preliminary study of elemental and Pb isotope analysis of 24 glandes plumbeae with different typologies accidentally discovered at Alto dos Cacos (Almeirim) and possibly related to the Roman army from Hispania Ulterior. The artefacts were analyzed by energy dispersive X‑ray fluorescence (EDXRF) and quadrupole based inductively coupled plasma mass spectrometry (ICP‑QMS). The elemental analysis indicates some trace elements in lead matrix. The lead isotope composition analyses distinguish two groups, regardless of typologies.
Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment, Mar 1, 2009
Harmful Algae, 2008
Foodborne outbreaks attributed to marine biotoxins were first reported in Portugal in 1946. A reg... more Foodborne outbreaks attributed to marine biotoxins were first reported in Portugal in 1946. A regular monitoring programme was implemented in 1986 for PSP, in 1987 for DSP and in 1996 for ASP. The gradual introduction of HPLC methodologies for DSP and PSP allowed ...
Avances Y Tendencias En Fitoplancton Toxico Y Biotoxinas Actas De La Ix Reunion Iberica Sobre Fitoplancton Toxico Y Biotoxinas Cartagena 7 10 De Mayo De 2007 2008 Isbn 978 84 96997 06 6 Pags 181 186, 2008
Localización: Avances y tendencias en fitoplancton tóxico y biotoxinas: actas de la IX Reunión Ib... more Localización: Avances y tendencias en fitoplancton tóxico y biotoxinas: actas de la IX Reunión Ibérica sobre Fitoplancton Tóxico y Biotoxinas, Cartagena 7-10 de mayo de 2007/coord. por Javier Gilabert, 2008, ISBN 978-84-96997-06-6, págs. 181-186
Environ. Sci.: Processes Impacts, 2016
High TE concentrations in soils from the Fildes Peninsula point to the urgent implementation of c... more High TE concentrations in soils from the Fildes Peninsula point to the urgent implementation of contamination control and remediation methodologies.
Journal of Chromatography a, Aug 10, 2007
The presence of paralytic shellfish poisoning (PSP) toxins has not been recorded in the Portugues... more The presence of paralytic shellfish poisoning (PSP) toxins has not been recorded in the Portuguese coast since 1995. A bloom of Gymnodinium catenatum occurred in the NW coast of Portugal in the autumn of 2005, and PSP profiles were determined in several inshore and offshore shellfish species by HPLC after pre-column oxidation. Most of the species studied contained a complex toxin profile, typically representative of contamination by G. catenatum. However, clams such as Spisula solida contained mainly decarbamoyl toxins, while less extensive transformation was found in Scrobicularia plana. In vitro incubation of S. solida digestive glands with PSP standards revealed a rapid transformation of carbamate and N-sulfocarbamoyl toxins into their corresponding decarbamate analogues. After 24 h, less than 5% of the carbamate or N-sulfocarbamoyl toxins tested remained. After a 24 h in vitro incubation of S. plana digestive glands, no decarbamate analogues were detected. Artificial toxification of S. plana with cultures of G. catenatum revealed the conversion into decarbamoyl analogues progressed slowly: initially dcGTX2 + 3 and dcSTX accounted only for 5% of total non N-1 hydroxilated toxins, after 6 days these toxins accounted for 41% of the toxin composition. In vitro incubations of digestive glands from other commercial bivalves did not reveal production of decarbamoyl analogues over a 24 h period.
In contrast to mussels (Mytilus galloprovincialis) and cockles (Cerastoderma edule), the clam Scr... more In contrast to mussels (Mytilus galloprovincialis) and cockles (Cerastoderma edule), the clam Scrobicularia plana has been observed to maintain PSP toxicity for long periods after a bloom event. Because this species is a deposit feeder, consumption of Gymnodinium catenatum cysts from the sediments was suggested as a possible explanation. In the autumn of 2005, a bloom of G. catenatum was detected along the NW coast of Portugal. The gut contents of S. plana from affected areas were examined for dinoflagellate cysts during and after the bloom, and the PSP content in the bivalves was followed by HPLC. The presence of G. catenatum cysts in gut contents was maximal during the bloom, and four months later still represented over 40 % of the cyst assemblage. Depuration experiments with S. plana mussels and cockles revealed that toxins in S. plana were almost undetectable within 1 week, while during the same period, a reduction to half the toxin burden was observed in mussels and cockles. The prolonged PSP toxicity observed in S. plana may primarily be a result of a species-specific slow depuration rate. However, consumption of toxic G. catenatum cysts cannot be ruled out as an additional source of toxicity.
Food Additives & Contaminants: Part A, 2009
Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry, Jan 24, 2018
The development of pharmacologically active compounds based on bis(thiosemicarbazones) (BTSC) and... more The development of pharmacologically active compounds based on bis(thiosemicarbazones) (BTSC) and on their coordination to metal centers constitutes a promising field of research. We have recently explored this class of ligands and their Cu(II) complexes for the design of cancer theranostics agents with enhanced uptake by tumoral cells. In the present work, we expand our focus to aliphatic and aromatic BTSC Zn(II) complexes bearing piperidine/morpholine pendant arms. The new complexes ZnL-ZnL were characterized by a variety of analytical techniques, which included single-crystal X-ray crystallography for ZnL and ZnL. Taking advantage of the fluorescent properties of the aromatic complexes, we investigated their cellular uptake kinetics and subcellular localization. Furthermore, we tried to elucidate the mechanism of action of the cytotoxic effect observed in human cancer cell line models. The results show that the aliphatic complexes (ZnL and ZnL) have a symmetrical structure, while...
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Papers by Susana Sousa Gomes
The collection was composed by 24 glandes plumbeae, obtained by different manufacture processes including casting. The lead isotope ratios obtained values by sample dissolution in HNO3 20% did not allow to establish groups having different isotopic compositions, which suggests a probable local production.
Bronze alloys from Fraga dos Corvos were composed by 4 archaeological artefacts and 2 fragments of metallurgical remains. In this case, after acid dissolution with HNO3 20%, the anodic electrochemical separation of Pb from the bronze matrix was performed. The obtained isotope ratio distribution patterns evidenced the existence of two distinct groups, which may indicate exogeneous influences and/or the use of ores with different origin
In the comparative study with Iberian mineralogical deposits, significant correspondences among the Pb isotopic patterns of bronze artefacts and those of mineral deposits from Sierra Morena and Basque-Cantabria basin were observed. Lead artefacts seem to be better associated to deposits from Andalusia-Murcia and Basque-Cantabria, but also from the south of France (Cévennes and Mont-Lozére Massif) and Sardinia.
A importância da interpretação da assinatura isotópica do Pb (204Pb, 206Pb, 207Pb e 208Pb) no estudo de proveniências e de rotas comerciais de artefactos metálicos, relaciona-se com o facto de a sua composição isotópica depender da idade geológica do depósito mineral donde foi extraído o metal, uma vez que não ocorre variação das razões isotópicas durante as diversas etapas da produção metalúrgica.
Neste trabalho apresentam-se os resultados obtidos na análise isotópica do chumbo, suplementada pela análise química, de um conjunto de 24 glandes plumbeae de tipologias diversas, descobertas acidentalmente no Alto dos Cacos (Almeirim) e eventualmente associadas ao Exército Romano da antiga Hispânia Ulterior. A análise elementar, não invasiva por EDXRF, permitiu identificar a presença de alguns elementos menores (Fe, Cu, Zn, Ag, Cd, Sn, Sb) com teores variáveis, tendo-se identificado 1 artefacto com teores mais elevados em estanho e 5 em ferro. A composição isotópica do Pb obtida por espectrometria de massa (ICP-QMS) parece indicar a existência de 2 grupos distintos, também associados a diferentes teores de elementos menores, embora independentes das tipologias dos artefactos.
The aim of this study was the determination of Pb isotope ratios of a set of bronzes recovered from Fraga dos Corvos (Macedo Cavaleiros) archaeological site, located in Northern Portugal [1]. The studied metallic artefacts have diverse typologies and include 2 bar fragments, 4 fibulae fragments, 1 pendant fragment and 1 cauldron fragment (?). Besides, 2 metallurgical remains (nodule and droplet) were also analyzed.
Previous elemental analysis by micro-EDXRF shows that bronzes have a Sn content varying between 5.1 and 13.9wt% and a Pb content from 1.4 to 6.1wt%, which allowed to select a suitable methodology for lead separation, prior to isotope ratio determinations. In such complex alloys the Pb isotope determinations (204Pb, 206Pb, 207Pb and 208Pb) are influenced by matrix effects that decrease the sensitivity and the reproducibility of the measurements. Analytical procedure followed the previously described in [2] and consisted in electrochemical Pb separation by anodic oxidation in a solution prepared with a small amount of material (~ 3 mg). The determination of Pb isotope ratios was made by ICP-MS with a quadrupole filter and provided the first results of Pb isotopic composition of bronze alloys from the Northern Portuguese territory. Preliminary determinations were obtained with a relative standard deviation below 0.5%.
Pb isotope ratio distributions allowed the identification of different composition patterns indicating probable distinct provenances, although similar isotopic ratios among some artefacts and metallurgical remains pointed out to local metallurgical activities.