Recent analytical applications of magnetic nanoparticles

Analytical chemistry has experienced, as well as other areas of science, a big change due to the needs and opportunities provided by analytical nanoscience and nanotechnology. Now, nanotechnology is increasingly proving to be a powerful ally of analytical chemistry to achieve its objectives, and to simplify analytical processes. Moreover, the information needs arising from the growing nanotechnological activity are opening an exciting new field of action for analytical chemists. Magnetic nanoparticles have been used in various fields owing to their unique properties including large specific surface area and simple separation with magnetic fields. For Analytical applications, they have been used mainly for sample preparation techniques (magnetic solid phase extraction with different advanced functional groups (layered double hydroxide, β-cyclodextrin, carbon nanotube, graphen, polymer, octadecylsilane) and automation of it, microextraction techniques) enantioseparation and chemosensors. This review summarizes the basic principles and achievements of magnetic nanoparticles in sample preparation techniques, enantioseparation and chemosensors. Also, some selected articles recently published (2010-2016) have been reviewed and discussed

Mikroekstrakcja w zatężaniu i oznaczaniu śladowych ilości pierwiastków technikami rentgenowskiej spektrometrii fluorescencyjnej

Nowadays, commonly applied analytical techniques allow determination of analytes on trace or ultratrace levels. However, the direct analysis of sample is not always possible due to low concentrations of analytes or too complicated matrix. Therefore, prior isolation and/or preconcentration step is necessary before the analysis. The one of the most popular sample pretreatment methodologies are extraction techniques such as liquid-liquid extraction (LLE) or solid-phase extraction (SPE). In order to eliminate the disadvantages of the classical extraction techniques, associated mainly with use of large amounts of organic solvents, microextraction techniques based on miniaturization of classical extraction modes are introduced. In microextraction techniques small sample volumes are analysed, therefore the volume of organic solvent is reduced and, in consequence, the amount of generated organic waste decreases. The aim of the PhD thesis is development of the analytical procedures enabling preconcentration and determination of a number of trace elements using X-ray fluorescence (XRF) techniques. The proposed procedures combine: • DLLME/EDXRF - dispersive liquid-liquid microextraction and energy-dispersive X-ray fluorescence spectrometry (EDXRF) for simultaneous determination of Fe(lll), Co(ll), Ni(ll), Cu(ll), Zn(ll), Ga(lll), Se(IV) and Pb(ll) ions with the use of ammonium pyrrolidinedithiocarbamate (APDC) and sodium diethyldithiocarbamate (Na-DDTC) as chelating agents and carbon tetrachloride as an extraction solvent, • DMSPE/TXRF - dispersive micro-solid phase extraction and total-reflection X-ray fluorescence spectrometry for determination of Cd(ll) and Pb(ll) ions with multiwalled carbon nanotubes MWCNTs as an adsorbent, • DMSPE/EDXRF - dispersive micro-solid phase extraction and energy-dispersive X-ray fluorescence spectrometry (EDXRF) for simultaneous determination of Co(ll), Cu(ll), Ni(ll) and Pb(ll) ions and speciation of Se, with graphene applied as an adsorbent. In order to obtain the best signal to background ratio, different modes of sample deposition onto the sample carrier were evaluated. Moreover, various parameters affecting recovery of extracted elements such as the sample pH, the amount of chelating agent (APDC or Na-DDTC), sample volume, the volume of extraction solvent/adsorbent and extraction/adsorption time were investigated. The proposed procedures enable very low detection limits to be obtained: (i) DLLME/EDXRF - from 1.6 to 4.1 ng mL1 for 5 mL samples, (ii) DMSPE/TXRF - from 1.0 to 2.1 ng mL1 for Pb (20 mL samples), (iii) DMSPE/EDXRF - from 0.23 to 1.1 ng mL"1 (for 50 mL samples) and 0.032 ng mL'1 for speciation of Se (for 75 mL samples). It is noteworthy that receiving such low detection limits was possible to obtain due to high enrichment factor values: DLLME/EDXRF - 250, DMSPE/TXRF - 40 and DMSPE/EDXRF - 418 (Pb) - 2553 (Cu). The proposed procedures are promising tools in multielemental analysis due to the possibility of simultaneous determination of enriched elements, low detection limits, simplicity, rapidity and low costs. Moreover, microextraction procedures extend the scope of XRF usage to liquid samples analysis and enable decreasing obtained detection limits over 1000 times

Miniaturized approaches for sample preparation in hair testing for drugs of abuse and their application in clinical and forensic scenarios

Hair is nowadays one of the most important alternative matrices that have attracted attention for the analysis of various drugs. The fact that it can be collected under supervision, the lower probability of tampering with, and the greater stability are cited as major advantages. As with conventional matrices, the preparation of hair samples is an important step for clean-up and pre-concentration of analytes, which significantly affects the reliability and accuracy of the analysis. The use of miniaturized pre-concentration techniques, driven by the concept of “green chemistry”, has minimized the waste usually associated to classical techniques, and microextraction techniques are known for using lower solvent volumes and for saving time; however, their applicability to hair samples is still poorly explored. The aim of this dissertation is to discuss the status of miniaturized clean-up approaches for hair samples. In addition, the advantages of microextraction by packed sorbent (MEPS) in different analytical fields are addressed, and the practical applicability of this technique in hair samples is demonstrated by three different works using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS): determination of selected opioids; determination methadone and EDDP; determination of cocaine and metabolites. These novel methods were optimized and validated according to internationally accepted guidelines. Regarding the current status of the application of miniaturized approaches to hair samples, an increased research has been observed in both solid-phase (SPME) and liquid phase microextraction (LPME), with SPME showing higher representativeness. In this last approach, dispersive micro-solid phase extraction (D-μ-SPE) emerges as the most used in the last 5 years, if we do not include the different variants of fibre microextraction, namely the direct immersion (DI-SPME), headspace (HS-SPME) or in tube (IT-SPME) approaches. Moreover, D-μ-SPE was the one that showed more innovations in terms of solid sorbent material, driven by developments with carbon nanotubes, graphene, graphene oxide (GO), and the use of modified magnetic nanoparticles (MNPs) and ion-imprinted polymers (IIPs). As for LPME, the use of hollow fibre (HF)-LPME has been extensively explored for hair samples, showing great versatility for target analytes. Improvements were also observed by functionalization with GO and by the use of ionic liquids (IL). However, when all variants of dispersive liquid-liquid microextraction (DLLME) are considered, this is undoubtedly the most researched approach. The inclusion of methods involving solidification of a floating organic drop (DLLME-SFO), supramolecular solvents (SM-DLLME), and temperature-controlled ionic liquids (TIL-DLLME) were considered very beneficial due to their lower toxicity. Of all the microextraction techniques applied to hair samples, MEPS seems to be little explored. In fact, before this project was initialized , there was only one paper that had applied MEPS to pre-concentrate analytes from hair samples. Nonetheless, MEPS has been successfully used to extract a variety of compounds from different matrices, and its applicability has been demonstrated in a number of areas, including therapeutic monitoring, forensic toxicology, and food and environmental analysis. This technique is considered as a miniaturization of the classical solid phase extraction (SPE) and was developed in 2004 by Abdel-Rehim with the aim of reducing the volumes of both the sample and the solvents. It also became very attractive as it allows the reuse of the sorbent material and offers an automated procedure by easy coupling to chromatographic systems. In MEPS, the sorbent is reduced (1-4 mg) and is located in a micro-syringe instead of a cartridge. In turn, the sample flows bidirectionally through the sorbent (aspirations), improving the efficiency of the process due to the increased interaction with the sorbent. Considering the potential of MEPS in the context of sample preparation, we decided to test its usefulness for hair samples in three applications. In the first work, we present an analytical method which was developed and validated for the determination of tramadol (TRM), codeine (COD), morphine (MOR), 6- acetylcodeine (6-AC), 6-monoacetylmorphine (6-MAM) and fentanyl (FNT) using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Using an M1 sorbent (4 mg; 80% C8 and 20% SCX), the procedure included the following steps: (i) conditioning (3 x 250 μL of methanol and 3 x 250 μL of 2% formic acid); (ii) sample load (15 x 150 μL); (iii) washing (150 μL of 3.36% formic acid); and (iv) elution (8 x 100 μL of 2.36% ammonium hydroxide in methanol). Linearity was obtained for all compounds between the lower limit of quantification (LLOQ) and 5 ng/mg, with determination coefficients higher than 0.99. The obtained LLOQs were 0.01 ng/mg for TRM, COD and 6-AC and 0.025 ng/mg for MOR, 6-MAM and FNT. The recoveries ranged from 74 to 90% (TRM), 51 to 59% (COD), 22 to 36% (MOR), 69 to 99% (6-AC), 53 to 61% (6-MAM) and 75 to 86% (FNT). The method proved to be precise and accurate with coefficients of variation typically below 15% and relative errors within a range of ± 15%, respectively. In the second work, a procedure was developed for the rapid concentration of methadone and its main metabolite (EDDP). The miniaturized approach was coupled to GC-MS/MS. MEPS was performed with an M1 (4 mg; 80% C8 and 20% SCX) sorbent conditioned with three cycles of methanol (250 μL) and three cycles of 2% formic acid (250 μL). Subsequently, the sample was loaded through nine cycles of 150 μL followed by a washing step that involved three cycles of 50 μL with 3.36% formic acid. For the elution of the compounds, six cycles of 100 μL with 2.36% ammonium hydroxide in methanol were used. The method was linear from 0.01 to 5 ng/mg for both compounds, with determination coefficients greater than 0.99. The recoveries ranged from 73 to 109% for methadone and from 84 to 110% for EDDP. Finally, precision and accuracy were in accordance with the international guidelines for analytical method validation. In the third work, a MEPS technique, with M1 (4 mg; 80% C8 and 20% SCX) sorbent, was developed for the pre-concentration of cocaine (COC), benzoylecgonine (BEG), ecgonine methyl ester (EME), norcocaine (NCOC), cocaethylene (COET) and anhydroecgonine methyl ester (AEME). The determination of the compounds was carried out using GC-MS/MS. The final procedure consisted of the following steps: (i) conditioning (250 μL of methanol and 250 μL of deionized water); (ii) sample load (21 x 150 μL); (iii) washing (50 μL of deionized water and 50 μL of acetate buffer pH 4); and (iv) elution (3 x 100 μL of 2% ammonium hydroxide in methanol). The obtained recoveries were considered acceptable for most compounds, namely 44-64% for COC, 63-73% for COET, 21-28% for BEG and 36-44% for NCOC. Lower recoveries were obtained for AEME (4-6%) and EME (1-3%). The method was linear between the LLOQs (0.010 ng/mg for COC and COET, 0.025 ng/mg for EME, BEG and NCOC and 0.150 ng/mg for AEME) and 5 ng/mg. In turn, the method was considered precise and accurate with coefficients of variation below 15%, and with an average relative error within ± 15% for all compounds, except for LLOQ (20%). With the successful application of MEPS it has been demonstrated that this miniaturized technique is an excellent alternative for toxicological analysis in hair samples. MEPS has the advantage of reducing solvent use, and the sorbent may be reused (> 100 extractions), which can be economically attractive to laboratories. Although there has been considerable academic interest in miniaturized clean-up approaches over the past five years, few implementations have been observed in routine laboratories. With the relevance and applicability herein described, we expect this panorama to change in the near future.A amostra de cabelo é uma das matrizes alternativas mais importantes. A sua análise foi relatada pela primeira vez no final dos anos 70, e desde então permitiu ajudar os toxicologistas nos mais diversos campos de atuação. Uma vez que as drogas são bastante estáveis nesta amostra, a sua análise proporciona a avaliação de histórias de uso de drogas ocorridas há centenas de anos, com grande interesse antropológico, mas também pode ser importante na resolução de casos forenses em que o cabelo é a única amostra obtida a partir de um cadáver. Já no indivíduo vivo, esta amostra é atualmente bastante utilizada para detetar xenobióticos (drogas de abuso, produtos farmacêuticos, contaminantes ambientais, agentes dopantes, etc.) em âmbito forense, em situações de renovação da carta de condução, avaliação do cumprimento da terapia de substituição de drogas, medicina ocupacional, avaliação e documentação de situações de abuso de álcool, entre outras. O facto de poder ser colhida sob supervisão com reduzida probabilidade de adulteração, e a elevada estabilidade são apontadas como as suas principais vantagens. Tal como acontece com as matrizes convencionais, a preparação das amostras revela-se uma etapa importante para a eliminação de interferentes e pré-concentração de analitos, influenciando significativamente a confiabilidade e a precisão da análise. Relativamente a esta matriz, as técnicas de preparação de amostra usadas não diferem das adotadas para outras matrizes, restringindo-se às clássicas extração em fase sólida (SPE) e extração líquido-líquido (LLE).No meio académico, estas técnicas convencionais são atualmente consideradas métodos do passado. Na última década testemunhou-se um rápido desenvolvimento de novas técnicas de preparação de amostras, existindo uma grande tendência para a miniaturização. O uso de técnicas miniaturizadas para pré-concentração permite ainda automatização, desempenho de alto rendimento, acoplamento online com instrumentos analíticos, resultando em baixos custos por análise devido ao reduzido consumo de solventes. As técnicas de microextração, como a microextração em fase líquida e microextração em fase sólida, apresentam essas vantagens sobre as abordagens clássicas, no entanto, a sua aplicabilidade em amostras de cabelo ainda está pouco explorada. Esta dissertação tem como objetivo demonstrar o estado atual das abordagens miniaturizadas para concentração de analitos em amostras de cabelo, as vantagens da microextração em seringa empacotada (MEPS) em diferentes campos analíticos e a sua aplicabilidade prática em amostras de cabelo com três trabalhos diferentes: determinação de opioides; determinação de metadona e EDDP, determinação de cocaína e metabolitos usando cromatografia gasosa acoplada à espectrometria de massa em tandem (GC-MS/MS). Relativamente ao estado atual das abordagens miniaturizadas aplicadas a amostras de cabelo, é possível afirmar que existiu um aumento na investigação envolvendo tanto a microextração em fase sólida (SPME) como em fase líquida (LPME), sendo que a SPME teve maior representatividade. Nesta última abordagem, a técnica de microextração em fase sólida dispersiva (D-μ-SPE) surge como a mais explorada nos últimos 5 anos, se não considerarmos em conjunto as diferentes variantes da microextração com fibra, nomeadamente a de imersão direta (DISPME), headspace (HS-SPME) ou capilar (IT-SPME). Adicionalmente, a D-μ-SPE foi a que apresentou mais novidades relativamente a sorbentes sólidos, impulsionada por desenvolvimentos com nanotubos de carbono, grafeno, óxido de grafeno (GO), para além do uso de nanopartículas magnéticas modificadas (MNPs) e polímeros impressos com iões (IIPs). No que se refere à LPME, o uso de fibra oca (HF)-LPME tem sido cada vez mais explorado em amostras de cabelo, revelando grande versatilidade em relação aos analitos alvo. Foram também observados aperfeiçoamentos através da funcionalização com GO e com a utilização de líquidos iónicos (IL). No entanto, se todas as variantes da microextração líquido-líquido dispersiva (DLLME) forem consideradas em conjunto, esta é sem dúvida a abordagem mais investigada. A inclusão de solidificação de gota orgânica flutuante (DLLME-SFO), solventes supramoleculares (SM-DLLME) e líquidos iónicos de temperatura controlada (TIL-DLLME) apresentaram como principal vantagem a menor toxicidade. Dentro de todas as técnicas de microextração aplicadas a amostras de cabelo, a MEPS surge como pouco explorada. De facto, à data do início deste projeto, apenas um trabalho havia aplicado a MEPS para isolar compostos a partir de amostras de cabelo. Contudo, a MEPS tem sido implementada com sucesso para extrair uma ampla gama de compostos a partir de diferentes matrizes. A sua aplicabilidade está comprovada nas mais diversas áreas, tais como monitorização terapêutica, toxicologia forense, bem como em análises alimentares e ambientais. Esta técnica é reconhecida como uma miniaturização da clássica SPE e foi desenvolvida em 2004 por Abdel-Rehim com o objetivo de reduzir o volume de amostra e solvente usados. Tornou-se ainda bastante atrativa por permitir a reutilização do material sorbente e proporcionar um procedimento automatizado através do fácil acoplamento aos sistemas cromatográficos. Na MEPS o enchimento é reduzido (1-4 mg) e fica localizado numa micro-seringa em vez de num cartucho. Por sua vez, a amostra flui através do enchimento de forma bidirecional (aspirações), melhorando assim a eficiência do processo devido ao aumento do contacto entre a amostra e o sorbente. Tendo em conta todas as potencialidades que a MEPS apresenta no âmbito de preparação de amostras, decidiu-se testar a sua utilidade para amostras de cabelo em três aplicações. Na primeira procedeu-se ao desenvolvimento e validação de um método analítico para determinar tramadol (TRM), codeína (COD), morfina (MOR), 6- acetilcodeína (6-AC), 6-monoacetilmorfina (6-MAM) e fentanil (FNT) em amostras de cabelo com recurso à GC-MS/MS. Utilizando um sorbente M1 (4 mg; 80% C8 e 20% SCX), o procedimento englobou os seguintes passos: (i) acondicionamento (3 x 250 μL de metanol e 3 x 250 μL de ácido fórmico 2%); (ii) passagem da amostra (15 x 150 μL); (iii) lavagem (150 μL de ácido fórmico a 3,36%); e (iv) eluição (8 x 100 μL de hidróxido de amónio 2,36% em metanol). Obteve-se linearidade para todos os compostos entre o limite inferior de quantificação (LLOQ) e 5 ng/mg, com coeficientes de determinação superiores a 0,99. Os LLOQs alcançados foram 0,01 ng/mg para TRM, COD e 6-AC e 0,025 ng/mg para MOR, 6-MAM e FNT. As recuperações variaram entre 74 e 90% (TRM), 51 e 59% (COD), 22 e 36% (MOR), 69 e 99% (6-AC), 53 e 61% (6-MAM) e 75 e 86% (FNT). O método revelou-se preciso e exato com coeficientes de variação tipicamente abaixo de 15% e erros relativos dentro de um intervalo de ± 15%, respetivamente. Na segunda aplicação, desenvolveu-se um procedimento para a rápida concentração de metadona e do seu principal metabolito (EDDP). A abordagem miniaturizada foi acoplada a GC-MS/MS. A MEPS foi efetuada com um sorbente M1 (4 mg; 80% C8 e 20% SCX) acondicionado com três ciclos de 250 μL de metanol e três ciclos de 250 μL de ácido fórmico a 2%. Posteriormente, a passagem da amostra fez-se com nove ciclos de 150 μL seguida de uma etapa de lavagem que envolveu três ciclos de 50 μL com ácido fórmico 3,36%. Para a eluição dos compostos, foram aplicados seis ciclos de 100 μL de hidróxido de amónio a 2,36% em metanol. O método foi linear de 0,01 a 5 ng/mg para ambos os compostos, apresentando coeficientes de determinação superiores a 0,99. As recuperações variaram entre 73 e 109% para metadona e 84 e 110% para EDDP. Por fim, a precisão e a exatidão estavam de acordo com os postulados das diretrizes internacionais para validação de métodos analíticos. Na terceira aplicação foi desenvolvida um método, também com recurso ao sorbente M1 (4 mg; 80% C8 e 20% SCX), para pré-concentração de cocaína (COC), benzoilecgonina (BEG), ecgonina metil éster (EME), norcocaína (NCOC), cocaetileno (COET) e anidroecgonina metil éster (AEME). A determinação dos compostos foi mais uma vez realizada com recurso à GC-MS/MS. O procedimento final consistiu nos seguintes passos: (i) acondicionamento (250 μL de metanol e 250 μL de água desionizada); (ii) passagem da amostra (21 x 150 μL); (iii) lavagem (50 μL de água desionizada e 50 μL de tampão acetato pH 4); e (iv) eluição (3 x 100 μL de hidróxido de amónio a 2%em metanol). As recuperações obtidas foram consideradas aceitáveis para a maioria dos compostos, nomeadamente 44-64% para COC, 63-73% para COET, 21-28% para BEG e 36-44% para NCOC. Foram obtidas recuperações mais baixas para AEME (4-6%) e EME (1-3%). O método foi linear entre os LLOQs e 5 ng/mg, sendo que os LLOQs foram 0,010 ng/mg para a COC e COET, 0,025 ng/mg para a EME, BEG e NCOC e 0,150 ng/mg para a AEME. Por sua vez, o método foi considerado também preciso e exato com coeficientes de variação inferiores a 15%, e com um erro relativo médio dentro de ± 15% para todos os compostos, exceto para o LLOQ (20%). Os três trabalhos tiveram uma etapa de otimização do procedimento de extração, a qual foi facilitada pelo uso do desenho experimental (DOE). O DOE é uma das principais ferramentas estatísticas com implementação na investigação e na indústria. Esta ferramenta permite o delineamento experimental, através de um número de ensaios definidos, com o objetivo de avaliar a influência de diversos fatores (variáveis) nas respostas obtidas de um processo. O DOE tornou-se vantajoso porque permitiu a otimização dos procedimentos analíticos através de um número reduzido de ensaios sem prejuízo da qualidade da informação obtida. Para além disso, permitiu ainda o estudo simultâneo das diferentes variáveis passiveis de afetar a MEPS. Com a aplicação bem-sucedida da MEPS nos trabalhos supracitados, foi possível comprovar que esta técnica miniaturizada se torna uma excelente alternativa para análises toxicológicas em amostras de cabelo. A MEPS é bastante vantajosa, reduzindo o uso de solventes e permitindo a reutilização do sorbente (> 100 extrações), o que pode ser economicamente atraente para laboratórios. Embora nos últimos cinco anos as abordagens miniaturizadas tenham despertado um grande interesse académico, poucas implementações têm sido observadas em laboratórios de análises de rotina. Com a relevância e aplicabilidades aqui descritas, esperamos que esse panorama mude num futuro próximo.We would also like to acknowledge the Centro de Competências em Cloud Computing in the form of a fellowship (C4_WP2.6_M1 – Bioinformatics; Operação UBIMEDICAL – CENTRO-01-0145- FEDER-000019 – C4 – Centro de Competências em Cloud Computing, supported by Fundo Europeu de Desenvolvimento Regional (FEDER) through the Programa Operacional Regional Centro (Centro 2020))

Investigation of Volatile Organic Compounds (VOCs) released as a result of spoilage in whole broccoli, carrots, onions and potatoes with HS-SPME and GC-MS

Vegetable spoilage renders a product undesirable due to changes in sensory characteristics. The aim of this study was to investigate the change in the fingerprint of VOC composition that occur as a result of spoilage in broccoli, carrots, onions and potatoes. SPME and GC-MS techniques were used to identify and determine the relative abundance of VOC associated with both fresh and spoilt vegetables. Although a number of similar compounds were detected in varying quantities in the headspace of fresh and spoilt samples, certain compounds which were detected in the headspace of spoilt vegetables were however absent in fresh samples. Analysis of the headspace of fresh vegetables indicated the presence of a variety of alkanes, alkenes and terpenes. Among VOCs identified in the spoilt samples were dimethyl disulphide and dimethyl sulphide in broccoli; Ethyl propanoate and Butyl acetate in carrots; 1-Propanethioland 2-Hexyl-5-methyl-3(2H)-furanone in onions; and 2, 3-Butanediol in potatoes. The overall results of this study indicate the presence of VOCs that can serve as potential biomarkers for early detection of quality deterioration and in turn enhance operational and quality control decisions in the vegetable industry

Development of Alternative Green Sample Preparation Techniques

The Special Issue of Separations, “Development of Alternative Green Sample Preparation Techniques”, provides an overview on recent trends in green sample preparation. This Special Issue of Separations collates 11 impressive contributions that describe the state-of-the-art in the development of green extraction technologies, from green materials for microextraction to the development of new sampling devices geometries for enhanced extraction efficiency and analysis throughput

Chemical characterisation of cherts from the valley of Serpis river (Alcoy, Alicante) for archaeological purpose

Mobility range and territorial control are central questions for Archaeology in the study of human groups’ life during Prehistoric Ages. A key point to get to grips with this set of problems is to understand the dynamics of supply of natural resources such as food and raw materials. Thus, the identification of the outcrops of chert and their characterisation is essential, due to the use of this particular rock as raw material for the production of several different tools. Since the nakedeye description of stone characters (colour, translucency, presence of carbonatation or patina, etc.) often lacks to identify different outcrops and to determine the provenance of a sample, in the last decades, scientists have tried to develop methods to improve the characterisation of this rock from the chemical, mineralogical and petrographic point of view [1,2]. This contribution shows the study of some chert varieties which were widely used since the Paleolithic by the inhabitants of the valley of Serpis river [3], in the southern part of the Valencian Community. Forty-three samples of Serrat, Mariola and Serreta chert were collected from different kinds of outcrops: from the wall rock, and from fluvial and colluvial deposits. The cortex or crust and the nucleus of each sample were mechanically separated and individually analysed to control the variability caused by the amount of cortex and consequently to develop a methodological approach that permits to identify different chert sources in a restricted area. For this purpose, Xray fluorescence and Inductively coupled plasma mass spectrometry analyses have been carried out to determine major elements, trace elements and rare earth elements [4] of cherts affected by different depositional and post-depositional conditions. [1] Luedtke, An Archaeologist's Guide to Chert and Flint (1992) 172. [2] Skarpelis et al., J. Archaeolog. Sci.: Rep. 12 (2017) 819. [3] Molina Hernández, El sílex del Prebético y cuencas neógenas en Alicante y sur de Valencia :su caracterización y estudio aplicado al Paleolítico Medio, tesis doctoral (2015) 902. [4] Murray, Sediment. Geol. 90 (1994) 213

Chemical characterisation of historic mortars to evaluate decay and construction phases

The chemical characterization of ancient mortars allowed the researchers to answer relevant questions about production technologies, raw materials supply, construction phases and state of decay. In this work one hundred and sixteen samples were collected from different structures during two archaeological excavations carried out in Sagunto’s city centre (Valencia, Spain). The studied area has been interested by several continuous phases of occupation since the Iberian Epoch (5th century BC) to the present times [1,2]. The samples were analysed employing X-ray fluorescence and Inductively coupled plasma mass spectrometry to determine major and trace elements. The obtained data was statistically processed with Sagunto’s Castle mortar results [3], allowing us to identify the construction phases of most of the wall structures, confirming the particular effectiveness of Rare Earth Elements analysis to distinguish mortars from different periods. In conclusion, according to this data, the state of conservation of the different mortars has been evaluated. [1] Ripollés, Opulentissima Saguntum (2004) 165. [2] Monserrat, Arse 41 (2007) 231. [3] Gallello et al., Microchem. J. 132 (2017) 251

Análisis químicos no destructivos sobre cinco mangos de marfil de Época Ibérica

Presentamos los análisis químicos realizados sobre un conjunto de cinco mangos de marfil época ibérica (s. VI – s. I a. C.). Son objetos con características técnicas, formales y decorativas muy similares entre sí, lo que que permite plantear una relación entre ellos en su proceso de producción. Sin embargo, fueron recuperados en cuatro yacimientos diferentes del área ibérica: los poblados de Turó de Montgròs (El Brull, Barcelona) y La Serreta (Alcoi, Alicante) y las necrópolis de El Cigarralejo (Mula, Murcia) y Coimbra del Barranco Ancho (Jumilla, Murcia), en esta última, se recuperaron dos de ellos. Todas las piezas, por sus contextos arqueológicos se datan entre el s. IV y principios del s. II a. C. Los análisis se llevaron a cabo con el objetivo de identificar la naturaleza y procedencia de las incrustaciones de carácter decorativo y la sustancia adherente todavía presentes en estos mangos. Si bien, en algunos de ellos, debido a su deteriorado estado de conservación, únicamente quedaban las improntas de las incrustaciones y no había restos aparentes de la sustancia de tono gris-negro que, presumiblemente, serviría para adherir las incrustaciones. Las piezas mejor conservadas son las recuperadas en lugares de hábitat. Los estudios se han realizado mediante técnicas no destructivas que no comprometiesen la integridad de las piezas. Así, se llevaron a cabo análisis por Fluorescencia de Rayos X (XRF), y por Espectrofotometría de Infrarrojo Cercano por Transformada de Fourier (FT-NIR). Todo ello se complementó mediante la revisión de los mangos con un microscopio electrónico de barrido equipado con un Sistema de Rayos X de Energía Dispersiva (SEM-EDAX-Sapphire), un microscopio óptico SMZ (NIKON) y un microscopio digital Dino-lite mod. AM7115MZT EDGE de 10x a 200x con una luz incidente por medio de un iluminador de fibra óptica y dotado de un software con funciones de medición integrales, para obtener imágenes de alta precisión. El análisis de XRF ha permitido identificar como estaño la sustancia empleada para adherir las incrustaciones decorativas en la pieza, empleando una técnica de tipo soldadura blanda. El FTNIR, por su parte, ha revelado que dichas incrustaciones fueron realizadas sobre resinas fósiles, muy probablemente ámbar. Estos resultados resultan totalmente novedosos dentro del mundo artesanal de época ibérica y, por tanto, de gran interés, evidenciando el valor de estas piezas en las que materias primas de presencia escasa en el mundo ibérico como son el marfil y el ámbar aparecen combinadas; así como el uso del estaño a modo de soldadura blanda nos revela procesos de manufactura no atestiguados hasta el momento en las industrias sobre materias duras de origen animal de la Edad del Hierro en la Península Ibérica. Cabe destacar que la realización de análisis químicos sobre piezas arqueológicas aporta datos específicos, prácticamente imposibles de obtener en un estudio macro o microscópico de los artefactos. Por ello, desde el proyecto proyecto “Madera, hueso, marfil, asta, concha ¿Artesanías marginales o marginadas?” (HAR2013-45770-P y ACOMP/2015/256) (financiado por el Ministerio de Economía y Competitividad y la Generalitat Valenciana) dirigido por la Dra. Consuelo Mata, se ha apostado por desarrollar estudios interdisciplinares, que impliquen el contacto y la comunicación entre distintos especialistas con la finalidad de conseguir resultados más sólidos y transversales

Rare Earth Elements to identify archaeological strata in the Cocina Cave

Rare earth elements (REE) have been employed in a variety of different scenarios in order to identify the natural or anthropogenic nature of archaeological soils [1,2] . In this study, REE signatures were employed to better understand the layers formation in a cavity called Cocina cave, a large cavity of 300 m2 located at Barranco de la Ventana, one of the ravines flowing southwards from La Canal valley, a little plateau located in the municipality of Dos Aguas (Valencia, Spain). Cocina cave is characterized of very homogenous sediment deposition where it is difficult to understand layers formation processes just employing the traditional archaeological methods and the standardized soil analyses. The archaeological sequence encompasses last hunter-gatherer Holocene occupations in the regional sequence (Mesolithic) followed by several levels attributed to the Neolithic, Bronze Age and historic occupations until the XX century, these last regarding the use of the cavity as a pen. In order to understand the development history of the strata and the anthropogenic or natural formation of soils a total of fifty samples were taken across six different sections (A, B, C, D, E, F, G) and from each section the sampling was carried out at different depths through 1-2m deep sections. All samples were recovered from current pits excavated at the cavity corresponding with some profiles that encompass different strata including natural deposits and hunter and penning activities together with other possible uses not well defined from archaeological data. Several radiocarbon dates confirm the anthropogenic use of the cavity from the IX millennium cal BP to the contemporary times. Major, minor and trace elements including REE were determined employing XRF and ICP- MS. Results were then statistically processed and cross-referenced with archaeological data to aid interpretation. The results show that REE provide interesting details regarding the strata development history, and therefore help archaeologists to better understand the occupation, use and abandonment phases of the cave. [1] Pastor et al., TrAC 78 (2016) 48. [2] Gallello et al., JAS 40 (2013) 799