5º MINISIMPOSIO MIQQI

(1)

2019-2020

.

Santiago de Compostela, La Coruña, Vigo, 25 de Xuño de 2020

5º MINISIMPOSIO MIQQI

5º MINISIMPOSIO INTERUNIVERSITARIO DO

MÁSTER EN INVESTIGACIÓN QUÍMICA E QUÍMICA INDUSTRIAL

(2)

5º SIMPOSIO MIQQI 25, 26 de xuño de 2020

INFORMACIÓN GENERAL

La asignatura Actividades Formativas Titorizadas incluye, entre otras actividades formativas, un Minisimposio Interuniversitario. En la edición del actual curso académico 2019‐2020, y debido a crisis sanitaria provocada por el Covid‐19, el simposio tendrá lugar a través de la plataforma virtual Microsoft Teams el día 25 de junio de 2020. El simposio se desarrollará en tres sesiones paralelas, para lo cual se han creado 3 equipos de MS Teams, uno por universidad, donde se han incluido a los participantes de cada una de las universidades, así como al conjunto del profesorado.

Actividades. Los alumnos deberán asistir a todas las conferencias que se organizan en su universidad. Cada estudiante deberá presentar una comunicación tipo póster que además deberá exponer y discutir (el orden de actuación y los tiempos los fija cada universidad) sobre el trabajo desarrollado en las asignaturas Prácticas Académicas y/o el Trabajo Fin de Máster, en gallego, castellano o inglés. Previamente, cada alumno elaborará un resumen de su comunicación, en inglés, utilizando la plantilla que se pone a su disposición. Estos resúmenes se incluyen en el libro del simposio.

Evaluación. La asistencia y participación en el Minisimposio será evaluada por una comisión científica integrada por profesores de las tres universidades, valiéndose de una plantilla o rúbrica elaborada por los profesores. La calificación obtenida será uno de los componentes de la calificación final de la asignatura Actividades Formativas Tutorizadas.

(3)

Comité Organizador

Universidade de Santiago de Compostela (USC)

 Dra. María Llompart Vizoso (Departamento de Química Analítica, Nutr. y Brom.)

 Dra. Mercedes Torneiro Abuin (Departamento de Química Orgánica)

Universidade da Coruña (UDC)

 Dr. Jesús José Fernández Sánchez (Departamento de Química)

 Dr. Carlos Jiménez González (Departamento de Química)

Universidade de Vigo (UVigo)

 Dra. Isabel Pastoriza Santos (Departamento de Química Física)

 Dra. María Beatriz Iglesias Antelo (Departamento de Química Orgánica)

Comité Científico

 Dra. María Llompart Vizoso (Departamento de Química Analítica, Nutr. y Brom.)

 Dra. Mercedes Torneiro Abuin (Departamento de Química Orgánica)

 Dr. Jesús José Fernández Sánchez (Departamento de Química)

 Dr. Carlos Jiménez González (Departamento de Química)

 Dra. Isabel Pastoriza Santos (Departamento de Química Física)

 Dra. María Beatriz Iglesias Antelo (Departamento de Química Orgánica)

(4)

Programa Sede USC: Jueves, 25 de junio de 2020

9:45-10:00 APERTURA

10:00-10:10 USC_01 Mª Cristina Álvarez García Chlorination study of antisychotic drugs in water 10:10-10:20 USC_02 Ana Arias Rodríguez Electron spectroscopy and data analysis techniques 10:20-10:30 USC_03 Belén Arjones Fernández Sensitivity to molecular amphiphiles stimuli 10:30-10:40 USC_04 Alexandre Blanco González Developing SprotiSci, from Protein to Melody

10:40-10:50 USC_05 Cristian Caamaño Fernández Simultaneous determination of acrylamide, 4-hydroxy-2-nonenal and melamine in food by GC-MS

10:50-11:00 USC_06 Yoselis del Carmen Casas Hernández Study of the correlation between curing degree of melamine and NIR equipment

11:00-11:10 USC_07 Adrián Casas Maceiras Energy and quality control at Finsa-Padrón

11:10-11:20 USC_08 Marco Crespo Señarís Preparation of new hybrid materials based on metal nanoparticles and polyphenylacetylenes

11:20-11:30 USC_09 Victoria Fernández Fernández Screening for surfactant in water by liquid chromatography coupled to high-resolution mass spectrometry

11:30-11:40 USC_10 Gardenia Gago Fraga Porto Muiños, The Vegetables of the ocean

11:40-11:50 USC_11 Roi Gómez García Water Splitting study using Atomic Quantum Cluster as catalyst 11:50-12:00 USC_12 Sara Illodo Brea Structural study of mitochondrial DNA’s quadruplexes

12:00-12:20 PAUSA CAFÉ

12:20-12:30 USC_13 Ana Justo Vega Development of preconcentration methods for the determination of silver and titanium dioxide nanoparticles in water samples 12:30-12:40 USC_14 Laura Lijó Salgueiro Benchmarking study of Electronic Laboratory Notebooks (ELNs) 12:40-12:50 USC_15 Noemí López Santos Metallosupramolecular complexes derived from a

bisthiosemicarbazone ligand 12:50-13:00 USC_16 José Luis Maneiro Moreira Analysis of meat samples by chromatography 13:00-13:10 USC_17 Sara Martínez Olveira FINANCIERA MADERERA S.A. (FINSA)

13:10-13:20 USC_18 Noemí Medella Ojea Determination of antioxidant capacity in fruits and vegetables 13:20-13:30 USC_19 Daniel Nieto Pastoriza A dysprosium metal complex: synthesis and solid state

characterisation

13:30-13:40 USC_20 Alberto Novo Pereira Cloud point extraction and ICP-MS for titanium speciation in water samples

13:40-13:50 USC_21 Miguel Otero Sáez de Lubiano Treatment of characterization data of different commercial TiO2 13:50-14:00 USC_22 María Paz Álvarez Physicochemical characterization of commercial semiconductor

oxide nanoparticles

14:00-14:10 USC_23 Tatiana Taboada Silva Study of the exposure to Bisphenols through the analysis of wastewater

14:10-14:20 USC_24 Lucía Vizcaino Anaya Encapsulation of polyoxometalates in carbon nanotubes for memory capacitor development

14:20-15:00 SESIÓN DE EVALUACIÓN

(5)

Programa Sede UDC: Jueves, 25 de junio de 2020

10:00-10:15 APERTURA

10:15-10:25 UDC_01 Sebastián Cebado Alonso Synthesis, characterization and study of properties of hybrid materials

10:25-10:35 UDC_02 Ignacio Delgado Ferreiro Use of derivatives of fishing waste to manufacture new materials 10:35-10:45 UDC_03 María Isabel González Pérez Determination of protein present in beer

10:45-10:55 UDC_04 Aitana Gutiérrez Lorente Natural gas as a fundamental part of the energy transition Aitana Gutiérrez Lorente

10:55-11:05 UDC_05 David Rodríguez Rodríguez

Phenolic compounds in vegetable wastes. An overview of extraction techniques and sources available.

11:05-11:30 PAUSA CAFÉ Simultaneous determination of acrylamide, 4-hydroxy-2-nonenal and melamine in food by GC-MS

11:30-11:40 UDC_06 José Antonio Souto Blanco Development of ecological lignin-based adhesives

11:40-11:50 UDC_07 Manuel Tato Martínez

Synthesis of substituted coumarins by crosscoupling reactions of indium organometallics

(6)

Programa Sede UVigo: Jueves, 25 de junio de 2020

10:00-10:15 APERTURA

10:15-10:30 UVigo_01 Sara Caruncho-Pérez

Proposed methodologies for detection, analysis, monitoring and elimination of pollutants: Drugs I

10:30-10:45 UVigo _02 Sergio Castro Estévez

Evaluation of the effectiveness of the stages of samples preparation for

the analysis of organic contaminants of foods of marine origin

10:45-11:00 UVigo _03 Uxía Gómez Synthesis of 20-epi vitamin D3 analogues

11:00-11:15 UVigo _04 Óscar Iglesias Menduiña Determination of the configuration of chiral non-racemic 1,3-diols 11:15-11:45 PAUSA CAFÉ Simultaneous determination of acrylamide, 4-hydroxy-2-nonenal

and melamine in food by GC-MS

11:45-12:00 UVigo _05 Xoel Martínez Rodríguez

Study of the absolute configuration of secondary amines for the total

synthesis of natural products

12:00-12:15 UVigo _06 Antonio Obelleiro Efficient synthesis of novel vitamin D analogues 12:15-12:30 UVigo _07 Clara Otero Martínez Design and production of organosiloxanes

12:30-12:45 UVigo _08 Marta Pita Fernández Design of traceable textile fibers applying Blockchain Technology

(7)

COMUNICACIONES ORALES

A continuación se recogen los resúmenes de las comunicaciones cortas impartidas por los alumnos de las tres Universidades en el orden que se indica a continuación:

 USC_01 a USC_024

 UDC_01 a UDC_07

 UVigo_01 a UVigo_08

(8)

5º SIMPOSIO MIQQI 25, 26 de xuño de 2020

Chlorination study of antisychotic drugs in water

Mª Cristina Álvarez García, Rosario Rodil Rodriguez¹, María Rosa Montes Goyanes¹, José Benito Quintana Álvarez ¹

1 Research Institute for Chemical and Biological Analysis (IAQBUS), University of Santiago de Compostela.

e-mail: mariacristina.alvarez.garcia@rai.usc.es

Pharmaceutical and personal care products are a large and diverse group of organic pollutants that have received increasing concern for their persistent properties and their high impact on ecosystems and human health. The presence of these compounds in various environmental matrices, their high persistence in wastewater, rivers, and even in previosly treated drinking water means that they have been classified as emerging pollutants. Currentrly, among the drugs most found in waters, stand out antipsychotic drugs. This is due to its wide use to treat mental illnesses, obsessive-compulsive disorders or another pathologies.

The main objetive of this master´s thesis is to carry out a degradation study with sodium hypochlorite (NaClO), an oxidizing agent commonly used in disinfection processes in water treatment plants, as well as to carry out a structural determination of possible by-products formed that could involve an equal or a higher risk than the drugs themselves. For this purpose, it has been used liquid chromatography (LC) coupled to tandem mass spectrometry with a hybrid quadrupole-time of flight (Q-TOF) system. As a result of the degradation, half-life times of 2-3 minutes are obtained for Amisulpride and 2-15 minutes for Sulpiride. Both compounds, in excess of NaClO, follow a pseudo order 1 kinetics. Finally, three degradation products have been found for Amisulpride and two for Sulpiride.

References

[1] BOLLMANN, Anna Franka, et al. Occurrence and fate of amisulpride, sulpiride, and lamotrigine in municipal wastewater treatment plants with biological treatment and ozonation. Journal of hazardous materials, 2016, vol. 320, p.

204-215.

[2] Utilización de antipsicóticos en España, 2010-2018. Dirección: https://www.aemps.gob.es/medicamentos-de-uso- humano/observatorio-de-uso-de medicamentos/informes/?lang=gl. Agencia Española de Medicamentos y Productos Sanitarios.

(9)

Electron spectroscopy and data analysis techniques

Ana Arias Rodríguez*, Flor Rodríguez Prieto, Carmen Ríos Rodríguez, Manuel Mosquera González

Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Dpto. de Química Física, Universidade de Santiago de Compostela, 15782 Santiago de

Compostela, Spain

*ana.arias.rodriguez@rai.usc.es and flor.rodriguez.prieto@usc.es

The relevance of quantifying parameters such as acidity, polarity or viscosity in chemically and biologically reactive microenvironments has caused a significant development of analytical techniques based on fluorescence spectroscopy. The research being done focuses on the use of fluorescent probes, taking advantage of the high sensitivity the fluorescence of these molecules experiences towards its surroundings, showing measurable changes on their behaviour influenced by the environment they are in. The aim of this work has therefore been to study in detail the usability and accuracy of a new analysis methodology for time-resolved fluorescence anisotropy measurements, utilizing spectroscopic data of 6-amino-1,3-benzothiazole-2-carbonitrile (ABTC, Figure 1) response in DMSO¹.

This new technique seeks, through the combined use of PCA (Principal Component Analysis) and global fits², to solve most of the issues (such as the establishment of t0) derived from the use of classical fluorescence anisotropy data analysis techniques. This recently proposed work methodology has been proved to be consistent, as it accurately represents experimental measurements performed in our studies (Figure 2), therefore consolidating itself as a robust alternative. Furthermore, the use of these tools precisely solves previously mentioned weaknesses, among which the need to set a value for t0 can be found, since now r0 (the desired parameter) is obtained instead as a result of the fit.

Figure 1. ABTC molecule Figure 2. ABTC in DMSO anisotropy measurements

References

(1) Lakowicz, J.R. 2006. Principles of Fluorescence Spectroscopy. 3ª ed., Springer. USA.

(2) Al-Soufi, W., Novo, M., Mosquera, M., & Rodríguez-Prieto, F. 2011. Principal component global analysis of series of fluorescence spectra. Reviews in Fluorescence 2009 (23-45). Springer, New York.

(10)

Sensitivity to molecular amphiphiles stimuli.

Belén Arjones Fernández

Physical Chemistry Department, CiQUS, Faculty of Chemistry, University of Santiago de Compostela, CiQUS, Santiago de Compostela.

bele04af@gmail.com

What arises is a bibliographic study of the molecular amphiphiles, self-assembled molecules that present a hydrophilic part and a hydrophobic part both covalently joined. Its investigation augmented throughout the years due to the fact that they are one of the main components of the biological membranes that assure the compartmental happening of biochemical processes instead of their chaotic happening in the individual. Thanks to this research, there are several current applications, both in industry and in daily life and also in biomedicine.

The usage of molecular amphiphiles in both aspects is based on the self-assembly quality that they present and that gives place to utile and organized structures with more stability and structural diversity than free molecules in solution. This ability is given due to its amphiphilicity that favours the water contact of the molecule but also avoids it, resulting in structures with a fully hydrophobic nucleus and a hydrophilic interface distributed around it. That is to say that by means of the self- assembly they suppress the non favourable interactions and encourages the favourable ones, which leads into a reduce of the system’s energy.

Controlling this self-assembly quality, by means of the amphiphilic control, there could be obtained systems in which the assembly and disassembly of the structures is reversible, providing good candidates for its use in different areas. The amphiphilic control and the change of the physiochemical proprieties could be achieved under stimuli such as enzymes¹, the pH², the reducing species², the CO23 or light⁴, from which demonstrating examples are provided. Obtaining CO2 sensibility, which presents a greater utility in the industry, the remaining stimuli could give rise to biomedical diagnosis applications and drug administration.

References

(1) Amir, R.J ; Zhong, S; Pochan, D.J; Hawker, C.J. Enzymatically Triggered Self-Assembly of Block Copolymers.

J.Am.Chem.Soc. 2009, 131, 13949–13951.

(2) Li, D; Bu,Y ; Zhang, L; Wang, X; Yang,Y; Zhuang, Y; Yang, F; Shen, H; Wu,D. Facile Construction of pH- and Redox-Responsive Micelles from a Biodegradable Poly(β-hydroxyl amine) for Drug Delivery.

Biomacromolecules. 2016, 17, 291-300.

(3) Liu, Y; Jessop, P.G; Cunningham, M; , Eckert, C.A; Liotta, C.L (2006). Switchable Surfactants. Science. 2006, 313, 958–960.

(4) Jiang, Y; Wang, Y; Ma, N; Wang, Z; Smet, M; Zhang, X. Reversible self-organization of a UV-responsive PEG-terminated malachite green derivative: vesicle formation and photo-induced disassembly. Langmuir. 2007, 23, 4029–4034.

(11)

Developing SprotiSci, from Protein to Melody

Alexandre Blanco González

Author's Affiliation: Department of Organic Chemistry, Centro Singular de Investigación en Materiais Biolóxicos e Moleculares, Universidade de Santiago de Compostela, Santiago de Compostela.

alexandre.blanco.gonzalez@rai.usc.es

Structure visualization has been around since the first tin ball and stick models used by Dorothy Crowfoot when she elucidated Penicilin’s 3D structure[1] in a ground breaking experiment using X- ray diffraction. Since then, computers have taken over the field and nowadays we have a plethora of software to put in easily interpretable images information about atom type, position, mass, charge, secondary structure etc. Despite of this, almost no attempt has been made in order to create a software that instead of sight, uses hearing to translate this information.

Following the steps of a research group from the MIT[2], we have developed an app based on python that can do just that. It takes structural information of virtually any pdb file registered in the RCSB and translates it to a melody encoding the type of aminoacid as the note pitch, the secondary structure as the note velocity and the distance of the residue to the protein’s centre of mass as the note volume.

Thus, we have created an algorithm or protocol, that might help people with impaired vision to imagine a protein’s composition and how it folds onto itself creating the final macromolecular shape.

References

(1) Hodgkin, D. C. (1949). The X-ray analysis of the structure of penicillin. Advancement of science, 6(22), 85-89.

(2) Franjou, S. L., Milazzo, M., Yu, C. H., & Buehler, M. J. (2019). Sounds interesting: can sonification help us design new proteins?. Expert review of proteomics, 16(11-12), 875-879.

(12)

Simultaneous determination of acrylamide, 4-hydroxy-2-nonenal and melamine in food by GC-MS.

Cristian Caamaño Fernández

Department of Analytical Chemistry, Faculty of Chemistry, University of Santiago de Compostela, Santiago de Compostela.

cristian.caamano.fernandez@rai.usc.es

The formation of many harmful compounds during the storage and processing of food is a very important concern for food science. These compounds may affect the organoleptic properties of food, decrease their nutritional value, and in some cases lead to the appearance of many diseases. Some examples of those compounds are acrylamide (AA), 4-hydroxy-2-nonenal (4-HNE) and melamine (MA).

Acrylamide (AA) is an amide originated in the Maillard Reaction, which is a non-enzymatic reaction between the carbonyl group of a reducing sugar with the free amino group of an amino acid or a protein. AA has been classified as an extremely hazardous substance by the United States Environmental Protection Agency (EPA) and the International Agency for research on Cancer (IARC) considers AA as Probably Carcinogenic to Humans (Category 2A). A Benchmark Dose Lower Confidence Limit (BMDL10) has been set at 0,17 mg/ kg of bw/day by the European Food Safety Authority (EFSA) ¹.4-Hydroxy-2-Monenal (4-HNE) is a hydroxyalquene α,β-insaturated produced in the lipid peroxidation reaction. The high reactivity of 4-HNE with the amino and thiol groups of some important biomolecules gives rise to its genotoxicity and cytotoxicity and for this reason a threshold of toxicological concern (TTC) at the level of 1,5 µg/kg of bw/day has been set by the EFSA ². Lastly, melamine (MA) is a food contaminant that contains a high level of nitrogen and it has been detected in adulterated food. MA can be also transferred into food by migration from packaging. EFSA has set a TDI at 0,2 mg/kg of bw/day for MA ³.

Here is presented a method for the simultaneous determination of AA, 4-HNE and MA in food by GC-MS. For this, a derivatization reaction with BSTFA, N,O-Bis(trimethylsilyl)trifluoroacetamide, is purposed. First, analytes has been derivatized with BSTFA in a US bath and later, liquid-liquid extraction with hexane has been done before GC-MS analysis. Limits of detection (LOD) and quantification (LOQ) haven been calculated as 3,3 and 10 times signal to noise ratio, respectively.

Analytical validation of the method has been assessed in terms of linearity using an internal standard calibration in the range of 0,01 to 1,6 ng/mL for AA and MA and 0,25-1,6 ng/mL for 4-HNE.

Accuracy, intra-day and inter-day precisions have been evaluated at 0,4, 0,8, and 1,6 ng/mL for all analytes achieving good results.

References

(1) Raffan, S., & Halford, N. G. (2019). Acrylamide in food: Progress in and prospects for genetic and agronomic solutions. Annals of Applied Biology, 175(3), 259-281.

(2) Liao, H., Zhu, M., & Chen, Y. (2020). 4-Hydroxy-2-nonenal in food products: A review of the toxicity, occurrence, mitigation strategies and analysis methods. Trends in Food Science & Technology, 96, 188-198 (3) EFSA Panel on Contaminants in the Food Chain (CONTAM) and EFSA Panel on Food Contact Materials,

Enzymes, Flavourings and Processing Aids (CEF). (2010). Scientific opinion on melamine in food and feed. EFSA Journal, 8(4), 1573.

Figure 1. Structure of Acrylamide. Figure 2. Structure of 4-Hydroxy-2-Nonenal. Figure 3. Structure of Melamine.

(13)

Study of the correlation between curing degree of melamine and NIR equipment.

Yoselis del Carmen Casas Hernández.

Master's student in chemical research and industrial chemistry. Faculty of Chemistry, University of Santiago de Compostela, USC, Santiago de Compostela. Spain. June 2020.

e-mail address: yoselisdelcarmen.casas@rai.usc.es

Melamine-formaldehyde resin (MF) is a melamine ring resin terminated with multiple hydroxyl groups derived from formaldehyde, it is formed through the condensation of formaldehyde with melamine to give, under idealized conditions, the hexahydroxymethyl derivative. Upon heating in the presence of acid, this or similar hydroxymethylated species undergo more condensation and crosslinking. ¹

MF resins are used as adhesives and finishing materials in the wood industry, mainly for the manufacture of boards impregnated by the resin. ² The MF in an impregnated paper sheet is not completely cured but still has a certain amount of residual activity and is applied directly in a hot press, on a wood-based panel, to which it bonds by completing the adhesive curing process.³ This process is controlled by 3 variables: Temperature, pressure and time. A smooth and flawless curing process is essential to obtain high quality products.

Finsa tries to improve the measurement of the curing degree of its melamine boards (boards laminated with melamine-formaldehyde resin, MF), using NIR equipment that allows the measurement of the degree of cure online. Until now the degree of curing has been determined with a simple methodology that provides visual, qualitative results. The process lasts 20 minutes and requires the destruction of the board sample.

The scope of the professional practices will be to take the samples and make tests with the current methodology, and then, by using the NIR equipment, a calibration must be done by comparing lines with previous results obtained. Measurements must also be made to establish curing limit values (with NIR) to be able to act on the production parameters (very little cured, and overcured) in order to set limit values.

References

(1) Melamine Resin. Wikipedia. (2020). https://en.wikipedia.org/wiki/Melamine_resin

(2) Weiss, S. Urdl, K. Mayer, H. Zikulnig, E. Kandelbauer, A. IR spectroscopy: Suitable method for determination of curing degree and crosslinking type in melamine–formaldehyde resins. Appl. Polym. Sci. 2019, 136, 47691.DOI: 10.1002/app.47691.

(3) Pizzi, A. Melamine–Formaldehyde Adhesives. Research Gate. 2003. DOI: 10.1201/9780203912225.ch32.

Figure Nº1: Idealized chemical reactions leading to the MF resin.¹ Figure Nº2: Laminated board structure.

(14)

Energy and quality control at Finsa-Padrón

Adrián Casas Maceiras

Quality control deparment at FINSA, Univesity of Santiago de Compostela, Santiago de Compostela

adricasas00@gmail.com

MDF fiber is produced from chips and shavings using a pressurized refining system. This is essentially a thermomechanical pulping process. The fiber is actually a collection of fiber bundles and individual wood cells, then a bonding agent or resin is used to coat de surface of the fibers¹. The global demand for MDF is increasing rapidly because the properties of this materials is better than the other particleboard. The main objective is to show how the quality of MDF boards is controlled,the standards applied, the quality control in this kind of board is essential in the making of safe product of high added value with a consistent properties.

The minimium energy requirements to make a MDF products at a industrial scale are important, and the cost of the finished product depends on it, therefore, it is necessary to perform a correct optimization and energy integration in the industrial plants to minimize consumption during the production. The cogeneration is a typical procedure for obtained useful thermal energy (steam, hot gases/oil) and electricity at the same time from biomass. In FINSA-PADRÓN this system is applied in a different way than usual in other plants.

Keywords: Cogenaration, MDF, Quality control, Medium Density Fibreboard. Biomass

References

(1) F.A. Kamke (2001). Wood: Nonstructural Panel Processes. Encyclopedia of Materials:

Science and Technology 1st Ed. 9673-9678.

(15)

Preparation of new hybrid materials based on metal nanoparticles and polyphenylacetylenes

Marco Crespo Señarís

CIQUS, Facultade de Química, Universidade de Santiago de Compostela.

e-mail address: marco.crespo@rai.usc.es

Stereocomplexes are supramolecular entities formed by the interaction of two complementary chiral polymers. Also, these new materials have different properties in comparison with the parent polymers¹. In this project a series of helical poly(phenylacetylene)s was synthesized. The aggregation of these polymers in dissolution was studied and a new type of fiber-like stereocomplex formed by the interaction and association of complementary chiral polymers was prepared. Gold and silver nanoparticles were synthesized too using these polymers as capping agents. Also, a new type of hybrid material based on stereocomplexes and gold and silver nanoparticles was prepared.

Figure 1. Preparation of hybrid materials based on stereocomplexes and metal nanoparticles.

References

(1) Leiras, S.; Freire, F.; Quiñoá. E; Riguera, R. Chem.Sci. 2015. 6, 246.

(16)

Screening for surfactant in water by liquid chromatography coupled to high-resolution mass spectrometry.

Victoria Fernández Fernández

Analytical chemistry department, Research Institute on Chemical and Biological Analysis (IAQBUS), University of Santiago de Compostela.

Victoria.fernandez.fernandez@rai.usc.es

In recent years, the presence of organic pollutants in the environment has been increasing exponentially, being industry one of the main sources of emissions. The toxicity of some substances implies health and environmental risks. Most of these compounds, for example surfactants, have an anthropogenic origin and can easily reach surface water.^1,2

The main objective of work is to use a screening method able to detect a great number of surfactants, using liquid chromatography coupled to high-resolution mass spectrometry (HPLC-QTOF). This work include the identification process of compounds found in a series of samples using the All Ions and Target MS/MS mode.

The developed workflow for the detection of surfactants was applied to 9 real samples of water from North Portugal and 27 compounds were detected.

References

(1) F. Hernández et al. (2015) Advancing towars universal screening for organic pollutants in Waters. Journal of Hazardous Materials 282. 86-95

(2) Montes R.; Aguirre J.; Vidal X.; Rodil R.; Cela R. and Quintana J.B. (2017) Screening for Polar Chemicals in Water by Trifunctional Mixed-Mode Liquid Chromatography−High Resolution Mass Spectrometry.

Environ. Sci. Technol. 51, 6250−6259

(17)

Screening de tensioactivos en agua mediante cromatografía de liquidos acoplada a espectrometría de masas de alta resolución

Victoria Fernández Fernández

Departamento de química analítica, Instituto de Investigación en Análisis Químicos y Biológicos (IAQBUS), Universidad de Santiago de Compostela.

Victoria.fernandez.fernandez@rai.usc.es

En los últimos años, la presencia de contaminantes orgánicos en el medioambiente ha ido aumentando exponencialmente, siendo la industria una de las principales fuentes de emisión. La toxicidad de algunas de estas sustancias supone un riesgo tanto a nivel sanitario como medioambiental. La mayoría de estos compuestos como por ejemplo los tensioactivos, tienen un origen antropogénico y pueden ingresar fácilmente en las aguas superficiales. ^1,2

El principal objetivo de este Trabajo Fin de Grado es emplear un método de screening (cribado) capaz de detectar el mayor número de tensioactivos en muestras de agua, mediante el uso de la cromatografía de líquidos acoplada a la espectrometría de masas en alta resolución (HPLC-QTOF).

En este trabajo se detalla el proceso de identificación de los compuestos encontrados en una serie muestras de agua mediante el modo de trabajo All Ions y Target MS/MS.

El protocolo de búsqueda desarrollado para la detección de los tensioactivos fue aplicado a 9 muestras de aguas del norte de Portugal, en las que se identificaron un total de 27 compuestos.

Referencias

(1) F. Hernández et al. (2015) Advancing towars universal screening for organic pollutants in Waters. Journal of Hazardous Materials 282. 86-95

(2) Montes R.; Aguirre J.; Vidal X.; Rodil R.; Cela R. and Quintana J.B. (2017) Screening for Polar Chemicals in Water by Trifunctional Mixed-Mode Liquid Chromatography−High Resolution Mass Spectrometry.

Environ. Sci. Technol. 51, 6250−6259

(18)

Porto Muiños, The Vegetables of the ocean.

Gardenia Gago Fraga

Quality Department, Porto Muiños, Poligono Industiral Acevedo, Parcela 14,151885 Cerceda, A Coruña.

gardenia.gago@rai.usc.es

Porto Muiños is a family-owned business which has commercialized algae since 1998. Furthermore, the company merchandizes other products such as sea urchin roe, monkfish liver, mussels with algae, algae infusion and wheat semolina with algae. All the products come from the Galician shore.

Algae are defined as photosynthetic organisms that have a simple reproductive structure. They may be seen as aquatic vegetables.

Algae can be classified following different criteria. According to their cellular organization, they are either microalgae (unicellular) or macroalgae (multicellular). Regarding their kingdom, they belong to: Plantae (known as green algae), Protista (both red and brown algae) and Monera (blue - green algae).

Algae are enrich in soluble fibers, minerals, vitamins and antioxidant, with a low content of fatty acids. Due to these properties, they have been used for centuries as a food ingredient in Asian countries. Recently, their use has spread to Western- countries cuisine. Porto Muiños offers a wide range of products based on algae and seafood, as mentioned above.

Given the characteristics of some algae, their use has been extended to the pharmaceutical and cosmetics industry.

Porto Muiños collects algae from the Atlantic ocean. Once the algae are in its facilities a control and a registration protocol are carried out. Afterwards, the algae are either treated as a fresh product or processed for preservation.

Porto Muiños is a ground-breaking company for the development of algae - crops systems in Spain.

The I+D department is focused on developing efficient crop systems for each species they work with.

The goal of I+D research is to preserve the natural environment while the effort of the workers is reduced.

Laboratories outside the company analyze chemical and microbiological algae parameters in order to assure that the products meet the criteria of the current market legislation.

In addition to chemical analysis mentioned above, the concentration of heavy metals such as mercury, cadmium, arsenic, tin, iodine and lead and also the humidity of the algae is determined. Some of species of algae have a high content in Iodine. The reduction of the Iodine concentration is a main topic for I+D department as it is known that high concentrations of Iodine in the diet are harmful.

References

http://portomuinos.com/ (06/05/2020).

Tesis doctoral: derivados cárnicos con algas, implicación sobre el metabolismos lipoproteico, estatus anitxidantes y protección proteica. (Adriana Rita Schultz Moreira, Universidad Compluetense de Madrid, 2014).

(19)

1 2 3

Water Splitting study using Atomic Quantum Cluster as catalyst

Roi Gómez García^(1)*, Melanie Guillén Soler⁽¹⁾, María del Carmen Giménez^(1)**

(1)Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)

*roi.gomez@rai.usc.es

** Department of Inorganic Chemistry of the University of Santiago de Compostela

The search of alternative energy conversion and storage systems has been stimulated in recent years with the aim to develop low cost, high efficiency, and low environment footprint systems. The electrochemical devices allowing the dissociation of water, (water splitting)¹, are one of the most promising for the generation of clean fuel (H2). These devices, called fuel cells, convert the chemical energy of the fuel directly into electrical energy by combining one oxygen atom with two hydrogen atoms that produce water and electricity in high efficiency. These technologies have become an attractive research area in recent years, especially in the search and development of abundant and cost-effective electrocatalyst materials for both the cathodic reaction of H₂ evolution (HER) as for the anodic reaction of O₂ evolution (OER) (1), since the relatively fast kinetics of HER/OER are currently restricted to the use of noble metals such as platinum, iridium or palladium.

In this context, the well-defined composition and size quantum atomic clusters², containing a very small number of atoms, have catalytic properties that depend mainly on their size, and their activity.

This properties can be altered only by modifying an atom of its composition due to "quantum confinement" (2). These quantum-sized effects (energy difference between HOMO-LUMO (3)), including small size and specific geometry provide these clusters completely novel properties, including for example, photoluminescence, improved catalytic activity, etc³…

References

(1) Lu, S., & Zhuang, Z. Science China Materials, 2016, 59(3), 217–238.

(2) Selva, J., Martínez, S. E., Buceta, D., Rodríguez-Vázquez, M. J., Blanco, M. C., López-Quintela, M. A., &

Egea, G. Journal of the American Chemical Society, 2010, 132(20), 6947–6954.

(3) Lu, Y. Z., Wei, W. T. & Chen, W. Chinese Science Bulletin, 2012, 57(1), 41–47.

(20)

Structural study of mitochondrial DNA’s quadruplexes

Sara Illodo Brea

Departamento de Química Física, Facultade de Química, Universidade de Santiago, Santiago de Compostela.

sara.illodo@rai.usc.es

One of the most studied biomolecules is the DNA given that it has all species’ genetic material and, therefore, understanding it implies understanding life itself. As the knowledge about DNA increased the appearance of new possible secondary structures of it became highly appealing for research.

Within these secondary structures lays the guanine quadruplexes (G-QP), highly polymorphic four- stranded structures that can be formed in guanine-rich sequences, which may be key to elucidate the transcription mechanism in mitochondria¹. Despite their relative abundance within the chromosomal DNA and our extensive knowledge about their folding and function, their formation in mitochondria is considered a rare event and the mechanism underlying their gene regulation function remains still unclear^2,3. With the aim to shed light on their formation we studied a series of guanine-rich sequences of DNA from the CSB II region that are thought to be responsible for this mechanism (GCG5AG7, GCG6AG7 and GCG6AG8) with spectroscopic tools.

The structural study of each sequence was done acquiring circular dichroism (CD) spectra in different environmental conditions followed by steady-state FRET measurements of those sequences that presented favourable results in CD. Circular dichroism spectra allowed us not only to determine which sequences could actually form G-QP, but also to decipher the topology of the G-QP that were formed in the studied samples. Additionally, FRET measurements allowed us to elucidate how salt concentration affected the formation of G-QP on those sequences in which we had previously observed their existence. Thus, we observed that those sequences with a higher number of guanines presented a higher tendency. In this way, our research entails the first step on the characterisation of these mitochondrial G-QPs formation and structure, which will signify a great advance on understanding these structures’ function in mitochondria when combined with further work and microscopy.

References

(1) Falabella, M.; Fernandez, R.J.; Johnson, B., & Kaufman, B. A. Current Medicinal Chemistry. 2018, 25.

(2) Hillen, H.S.; Parshin, A. V.; Agaronyan, K.; Morozov, Y. I.; Graber, J. J.; Chernev, A.; Temiakov, D. Cell. 2017, 171(5), 1082-1093.e13.

(3) Zheng, K.; Wu, R.; He, Y.; Xiao, S.; Zhang, J.; Liu, J.; Tan, Z. Nucleic Acids Research. 2014, 42(16). 10832- 10844.

Figure 1. a) G-QP's structural scheme, b) CD spectra and, c) FRET spectra

(21)

Development of preconcentration methods for the determination of silver and titanium dioxide nanoparticles in water samples

Ana Justo Vega

Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Santiago de Compostela 15782, Spain

ana.justo.vega@rai.usc.es

According to the International Organization for Standardization (ISO), nanoparticle (NP) is defined as a nano-object with all external dimensions in the nanoscale (1 nm to 100 nm)¹. These nanomaterials exert extraordinary properties compared to their fine particle analogous. Due to this, they have aroused particular interest in recent years. Silver (Ag) and titanium dioxide (TiO2) NPs have been incorporated in a wide range of consumers’ products, such as sunscreens, food additives, cosmetics, wound dressings, textiles or biomedical devices^2,3. As a consequence of the increasingly use of these nanomaterials they are inevitably released into the environment. There is a lack of toxicological data regarding the possible effects of nanomaterials in human health and in the environment. Further investigation is therefore needed. New strategies for the detection, characterization and quantification of NPs in environmental samples are required. This study aims at trying to fill the gap with the development of a new method for the determination of Ag and TiO2 nanoparticles.

A method coupling surfactant assisted dispersive liquid liquid microextraction (SA-DLLME) for the extraction of NPs with inductively coupled plasma mass spectrometry (ICP-MS) for the determination, was proposed for the analysis of Ag and TiO2 NPs in water samples. Experimental parameters affecting the efficiency of SA-DLLME, such as volume of surfactant/extractant mixture, vortex time, speed of vortex, centrifugation time and speed of centrifugation were investigated.

Furthermore, an effective separation of TiO2 NPs from its ionic species was achieved by SA-DLLME.

Compared to other techniques for NPs analysis, SA-DLLME was found to present high extraction efficiency, low cost, simplicity of operation and less consumption of organic solvents which reduce environmental hazards and fulfil the aim of the so-called green chemistry.

References

(1) International Organization for Standardization (ISO).ISO/TR18401:2017 (en) Nanotechnologies-Plain

language explanation of selected terms from the ISO/IEC 80004 series. Online 12 March 2020. Available from URL: https://www.iso.org/obp/ui/#iso:std:iso:tr:18401:ed-1:v1:en

(2) M. S. Waghmode, A. B. Gunjal, J. A. Mulla, N. N. Patil, and N. N. Nawani, “Studies on the titanium dioxide nanoparticles: biosynthesis, applications and remediation”, SN Appl. Sci., vol. 1, no. 4, pp. 1–9, 2019, doi:10.1007/s42452-019-0337-3.

(3) X. F. Zhang, Z. G. Liu, W. Shen, and S. Gurunathan, “Silver nanoparticles: Synthesis, characterization, properties, applications, and therapeutic approaches”, Int. J. Mol. Sci., vol. 17, no. 9, 2016,

doi:10.3390/ijms17091534.

Figure 1. Left, TEM images of Ag NPs (ø 40 nm). Right, image of TiO2 NPs (ø 50 nm).

(22)

Benchmarking study of Electronic Laboratory Notebooks (ELNs)

Lijó Salgueiro, Laura.

Marketing & sales department, Mestrelab Research, Santiago de Compostela.

Laura.lijo@rai.usc.es

An electronic laboratoy notebook (or ELN) is a software designed to replace paper laboratory notebooks. ELNs in general are used by scientists, engineers, and technicians to document research, experiments, and procedures performed in a laboratory. ELNs stand out for significantly improving the efficiency of the researcher, allowing a more fluid collaborative work and improving team performance. Mbook is the ELN of Mestrelab Research, designed by chemists for chemists¹. The aim of study is to identify strengths and advantages of competing products to ascertain new features for Mbook and therefore achieve better quality software, as well as improvements in marketing communications, user satisfaction and reducing the learning time required to start using Mbook.

In this project the technique of Benchmarking is applied to Mbook. To this end, a technical comparison of the product was made with similar products on the market. These products were pre- selected by Mestrelab’s management and sales team, based on feedback from Academia and industry, to represent the main competitors of Mbook. Functional features, price structure and product offer of several ELNs were benchmarked with Mbook by comparing marketing materials available online and conducting free trials.

Other types of marketing techniques for ELN analysis have also been carried out, such as a survey about ELNs (for product feedback from ELN users and non-users), in-depth analysis of Mbook resources (from the homepage to the software's user manual²) and an analysis of the registering process of other ELNs, key in obtaining new users.

A series of conclusions and recommendations for the improvement of the product were obtained for the different departments of the company, from sales to development.

References

(1) Mestrelab Research . Mbook. [En línea].[Citado el 10 de abril de 2020]. https://mestrelab.com/software/mbook/.

(2) Mestrelab Research. Mbook resources. [En línea]. [Citado el 10 de abril de 2020].

https://mestrelab.com/learn_support/mbook/.

(23)

Metallosupramolecular complexes derived from a bisthiosemicarbazone ligand

Noemí López, Sandra Fernández-Fariña, Ana M. González-Noya, Rosa Pedrido Departamento de Química Inorgánica, Facultad de Química, Universidade de Santiago de Compostela, Campus Vida, Santiago de Compostela.

E-mail: noemi.lopez.santos@rai.usc.es

Metallosupramolecular chemistry is a research field that has undergone significant development in recent years due to the variety of architectures that can be achieved by self-assembly processes driven by metal ions.¹ Among the wide set of metallosupramolecular compounds, helicates are very interesting due to their applications in areas such as nanotechnology or biomedicine.² Helicates are chiral compounds in which the ligands are twisted around the metal ions,³ exhibiting structures reminiscent of DNA. Bisthiosemicarbazone ligands are of great interest for the preparation of these compounds due to their versatility as donor systems and their biological properties.⁴

In this work, it was carried out the designing, synthesis and characterization of Co(II) and Ni(II) helicates derived from a pentadentate [N3S2] bisthiosemicarbazone ligand H2L (Scheme 1). The ligand was obtained by a condensation reaction, while metal complexes were prepared by using an electrochemical procedure. All compounds were completely characterized in solid state and in solution with the usual techniques. Moreover, single crystals of the nickel complex were obtained and its structure was determined by X-ray diffraction [Ni2L2]·CH3CN (Scheme 1), confirming its helical structure.

Scheme 1. Structure of the Ni(II) dihelicate derived from the bisthiosemicarbazone ligand H2L.

References

(1) Casini, A.; Woods, B.; Wenzel, M. Inorg. Chem., 2017, 56, 14715-14729.

(2) a) Kaner, R. A.; Allison, S. J.; Faulkner, A. D.; Philips, R. M.; Roper, D. I.; Shepherd, S. L.; Simpson, D. H.;

Waterfield, N. R.; Scott, P. Chem. Sci. 2016, 7, 951-958; b) Ferrando-Soria, J.; Fabelo, O.; Castellano, M.;

Cano, J.; Fordham, S.; Zhou, H.-C.; Chem. Commun., 2015, 51, 13381-13384.

(3) Romero, M. J.; Martínez-Calvo, M.; Maneiro,M.; Zaragoza, G.; Pedrido,^,R.; González-Noya,A. M.; Inorg.

Chem., 2019, 58, 881-889.

(4) Yu, P.; Deng, J.; Cai, J.; Zhang, Z.; Zhang, J.; Hamid Khan, M.; Liang, H.; Yang, F. Metallomics, 2019, 11, 1372-1386.

(24)

Analysis of meat samples by chromatography

José Luis Maneiro Moreira

Chromatography lab at Meat Technology Centre of Galicia, Ourense. Joseluis.maneiro@rai.usc.es The aim of this internship of Master is to learn basic skills at the chromatography laboratory. In this document it will be explained some of the daily tasks that I am realizing at the Meat Technology Centre (CTC).

ABSTRACT

The Meat Technology Centre is a foundation launching in 2005 to help the development of the agro- food industry of Galicia and make it a reference in Spain. It is situated in the technology park of San Cibrao das Viñas (Ourense). It consists in a building with advanced facilities such as a pilot plant and four different labs: physicochemical, microbiology, sensorial and chromatographic. The centre gives support to the agro-industry and galician meat companies, in order to improve the quality of the meat and products developing R+D+i projects.

My work is focused on chromatographic determinations. My main task consists in the sample pre- treatment before the analysis. We carry out several types of analysis to determine analytes such as fatty acids, amino acids, volatile compounds and minerals.

The sample preparation for fatty acids involves two steps, the first one is the extraction. It consists in the trituration of 10 g of meat sample with organic and aqueous solvents, followed by the centrifugation to separate the organic phase. Subsequently, the lower phase is evaporated to dryness until getting the fat sample. The second step is the methylation, that consists in a Base-Catalysed Transesterification with sodium methoxide followed by another acid-catalysed esterification and transesterification in H2SO/MeOH 10%. The quantification is achieved by GC/FID.

Considering amino acids, the sample preparation begins with an extraction too, in this case in an acid media. For free amino acids, it is used 6 N HCl in an ice-cold bath, whereas for hydrolyzed amino acids it is 0.1 N HCl under 24 hours incubation at 110 ºC. The process is slightly different but with the same concept. Once the extraction is completed, a derivatization phase is needed. The analysis is made by HPLC.

Another kind of analysis is the determination of volatile compounds profile.in this case it is needed to put the sample in a vial and introduce it in the GC/MS where the sample is heated helping the volatiles compounds to be adsorbed by the SPME fibre. Afterwards, the analytes on the fibre are thermally desorbed in the GC injector and transferred to the GC column.

Regards minerals, it is required to calcinate the sample and then dissolve it with a nitric acid solution.

The final solution will be introduced in the ICP-OES.

References

(1) https://ceteca.net/es/, (Web Meat Technology Centre, Ourense).

(2) Bligh EG, Dyer WJ. A rapid method of total lipid extraction and purification. Can J Biochem Physiol.

1959;37:911–7.

(3) W.W. Christie. Advances in Lipid Methodology - Two, pp. Ed. W.W. Christie, Oily Press, Dundee. 1993; 69- 111.

(4) Yanwen Sun, Mangjuan Fu et al. Evaluation of Freshness in Determination of Volatile Organic Compounds Released from Pork by HS-SPME-GC-MS. Food Analytical Methods, 2017; 11:1321–1329.

(25)

FINANCIERA MADERERA S.A. (FINSA)

Sara Martínez Olveira

sara.martinez.olveira@rai.usc.es

Financiera Maderera S.A. (FINSA) is a company in the wood transformation sector founded in 1931 in the municipality of Ames, A Coruña. This company, which started as a sawmill, currently has as its social purpose the purchase, processing and sale of wood and auxiliary products of the wood industry, both in the national and international markets.^1,2,3

Wood is a sustainable, renewable and recyclable resource. FINSA resorts to sustainable forest management, using raw materials from certified forests. Both industry and habitual consumption habits generate CO2 and one of today's challenges is to reduce emissions. Fortunately, trees contribute to its absorption by storing it in the wood so, by using this raw material, CO2 emissions into the atmosphere are considerably reduced.^1,2

It has 20 production centres in Spain, France, Ireland, the Netherlands, Italy, Latin America, Morocco, Poland, Portugal, the United Kingdom and the UAE. It also has a large logistics network which make it possible to serve more than 80 countries around the world. Due to this, it is considered one of the leading companies in the wood transformation sector in Europe.^1,2

FINSA has developed its own Management Model based on the Kaizen method, which prioritizes teamwork, effective effort and mutual respect, and is based on basic pillars such as motivation, prevention, costs, service, quality and innovation.^1,2

According to the latest data available, in 2018 FINSA had 3347 employees, with sales of 916 million euros and an investment of 86 million euros.²

FINSA has achieved the position 268 in the National Ranking of Companies, the position 14 in the Provincial Ranking and the position 1 in the Ranking of Companies in the Manufacture of Veneer and Wooden Panels Sector.⁴

References

(1) Financiera Maderera S.A. (FINSA)]. (23 feb. 2016). Video Corporativo Finsa (Versión Larga). [Video].

Recuperado 8 de junio de 2020, https://www.youtube.com/watch?v=WDn90yGbVTs&feature=emb_logo (2) FINSA (2020). Recuperado 8 de junio de 2020, https://www.finsa.com/

(3) eINFORMA (2020). Recuperado 8 de junio de 2020, https://www.einforma.com/informacion- empresa/financiera-maderera

(4) Ranking empresas – El economista (2018). Recuperado 9 de junio de 2020, https://ranking- empresas.eleconomista.es/FINANCIERA-MADERERA.html

Figura 1. Evolución de Empleados.³ Figura 2. Evolución de Ventas.³

(26)

Determination of antioxidant capacity in fruits and vegetables.

Noemi Medela Ojea

Physiochemistry Department, Centro Tecnolóxico da Carne, Ourense noemi.medela@rai.usc.es

The Centro Tecnolóxico da Carne is an institution that performs certain analyses on different foods (mainly meat) to guarantee their good condition. At the same time, this institution develops research and development of new products. For this purpose, it cooperates in studies with various companies in the food industry, with which it has an agreement.

At present there is a new model of healthy eating, which prioritizes healthy and safe food. In this regard, the search for natural antioxidant substances to the detriment of synthetic ones is of special interest. On the other hand, fruits and their by-products are widely known matrices for their antioxidant substances, which could be used in the meat industry as natural antioxidants. Before incorporating these extracts into meat products, it is necessary to study antioxidant capacity, taking into account that the main antioxidants usually found in fruits and vegetables are carotenoids, terpenoids and vitamin C, among others. To carry out a study of them it is necessary to use different methods that allow us to analyse the antioxidant capacity. For the study to give representative results, it is necessary to combine different methods. Among the methods used in the practices are:

DPPH method, which consists of the capture of the proton by the 1-1-diphenyl-2-pycrilhidrazyl radical; FRAP assay, which consists of the reduction of the ferric form of the iron-trypyridyltriazine complex to the ferrous form; and ABTS study, which consists of the discoloration of the 2,2’-azino- bis-3-ethylbenzothiazolin-6-sulfonic acid radical. The following pictures show the different reactions that take place in DPPH method (1), the FRAP method (2) and the ABTS method (3):

1 2 3

References

(1) Centro Tecnolóxico da Carne (CeTeCa), guías de procedimiento propias y página web: https://ceteca.net/

(visitada el 30 de mayo de 2020).

(2) Moura, M.S; Elesbao, R.; Sousa, E.; Morais, S.M.; Goes Sampaio, C.; Pérez, J.; Saura-Calixto, F.D.

Determinación da actividade antioxidante polo método de redución de ferro (FRAP)(2006)

(3) Pérez-Jiménez, J.; Saura-Calixto, F. Metodología para la evaluación de capacidad antioxidante en frutas y hortalizas (S8-0131). Congreso iberoamericano de tecnología postcosecha y agroexportaciones. (2007) (4) Kuskoski, E. M; Asuero, A.G.; Troncoso, A.M.; Aplicación de diversos métodos químicos para determiner

actividad antioxidante en pulpa de frutos.Cienc.Tecnol.Aliment, Campinas 25(4): 726-732, (out-dez. 2005)

(27)

5º SIMPOSIO MIQQI 25, 26 de Xuño de 2020

A dysprosium metal complex: synthesis and solid state characterisation

Daniel Nieto-Pastoriza,* Matilde Fondo, Jesús Sanmartín-Matalobos, Julio Corredoira-Vázquez, Ana M. García-Deibe

Departamento de Química Inorgánica, Facultade de Química, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.

e-mail address: daniel.nieto.pastoriza@rai.usc.es

The field of molecular magnetic materials has received great attention since the discovery of the first single molecular magnet (SMM) by Gatteschi et al in 1993.¹ The significance and knowledge of this field has gradually increased, and nowadays it is well-known that the search for high-performance SMMs must be based on molecules with high anisotropy, high spin ground state, as well as a bistable ground state. All these properties are inherent to lanthanoid(III) ions, and, accordingly, the search for molecular magnets is increasingly focused on the isolation of complexes with lanthanoids as metal centres.²

With these considerations in mind, the present work describes the synthesis and structural characterisation of the dysprosium(III) complex [Dy(L)(Cl)(H2O)2] (1).

Scheme. Reaction conditions for the isolation of 1.

This dysprosium metal complex was fully characterised in solid state by analytical and spectroscopic methods, as well as by single crystal X-ray diffraction studies. This characterisation reveals that the complex has been isolated with high purity, and that the dysprosium metal centre is octacoordinate in a triangular dodecahedron environment, according to the SHAPE program.³

References

(1) (a) Sessoli, R.; Gatteschi, D.; Caneschi, A., Novak, M. A. Nature 1993, 365, 141-143; (b) Sessoli, R.; Tsai, H.-L.;

Schake, A. R.; Wang, S.; Vincent, J. B.; Folting, K.; Gatteschi, D.; Christou, G.; Hendrickson, D. N. J. Am. Chem. Soc.

1993, 115, 1804-1816.

(2) Zhu, Z.; Guo, M; Li, X-L.; Tang, J. Coord. Chem. Rev. 2019, 378, 350–364.

(3) Llunell, M.; Casanova, D.; Cirera, J.; Alemany, P.; Alvarez, S. SHAPE: Program for the stereochemical analysis of molecular fragments by means of continuous shape measures and associated tools; University of Barcelona, Barcelona, España, 2010.

(28)

25, 26 de junio de 2020

Cloud point extraction and ICP-MS for titanium speciation in water samples

Alberto Novo Pereira

Master en Investigación Química y Química Industrial

ABSTRACT

There are different analytical techniques available in the literature to carry out the identification, characterization and quantification of NPs in multiple matrix samples (water).

In this study, the development of a novel analytical method for the separation and determination of titanium dioxide (TiO₂) nanoparticles in water samples has been carried out. The separation was performed using the Cloud Point Extraction (CPE) procedure with the commercial surfactant Triton X-114, in addition to using ultrasonic energy and centrifugation. Titanium dioxide (TiO2) nanoparticles were analyzed in the surfactant-rich phase and ionic titanium nanoparticles in the surfactant lean phase by inductively coupled plasma mass spectrometry (ICP-MS). Parameters related to the cloud point extraction procedure such as Triton X-114 and NaCl concentrations were evaluated. To develop this study, optimal concentrations of 0.03% (w / v) and 2.5 mM of Triton X- 114 and NaCl, respectively, were selected. The extracted TiO2 nanoparticles were digested using HNO3 and H2O2 in an ultrasonic bath for 10 minutes at 60 ° C and subsequently analyzed by ICP- MS.

The analytical characteristics of the method (calibration, limits of detection and quantification, precision and recovery) were evaluated and showed very good results. Finally, the method was applied for the determination of TiO₂ nanoparticles in a pool of water samples.

Referencias

1) M. Auffan, J. Rose, J.Y. Bottero, G.V. Lowry, J.P. Jovilet, M.R. Wiesner, Towards a definition of inorganic nanoparticles from an environmental, health and safety perspective, Nat. Nanotechnol. 4 (2009) 634–641 https://doi.org/10.1038/nnano. 2009.242.

2) S.K. Jeon, E.J. Kim, J. Lee, S. Lee, Potential risks of TiO2 and ZnO nanoparticles released from sunscreens into outdoor swimming pools, J. Hazard. Mat. 317 (2016) 312–318 https://10.1016/j.jhazmat.2016.05.099.

3) J. Liu, R. Liu, Y. Yin, G. Jiang, Triton X-114 based cloud point extraction: a thermoreversible approach for separation/concentration and dispersion of nanomaterials in the aqueous phase, Chem. Commun. 28 (12) (2009) 1514–1516 https://10.1039/B821124H.

4) A.L. Fabricius, L. Duester, B. Meermann, T.A. Ternes, ICP-MS-based characterization of inorganic nanoparticles—

sample preparation and off-line fractionation strategies, Anal. Bioanal. Chem. 406 (2014) 467–479 https://10.1007/s00216-013-7480-2.