Chemistry Commons^™

Confocal Raman Spectroscopic Imaging For In Vitro Monitoring Of Active Ingredient Penetration And Distribution In Reconstructed Human Epidermis Model, Lynda Miloudi, Franck Bonnier, Ali Tfayli, Florent Yvergnaux, Hugh Byrne, Igor Chourpa, Emilie Munnier

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Topically applied Active Cosmetic Ingredients (ACI) or Active Pharmaceutical Ingredients (API) efficacy is directly related to their efficiency of penetration in the skin. In vitro Reconstructed Human Epidermis (RHE) surrogate models offer in vivo like skin samples for transdermal studies. Using Delipidol®, an ACI currently used in the cosmetics industry, the capabilities to deliver accurate distribution maps and penetration profiles of this molecule by means of Confocal Raman spectroscopic Imaging have been demonstrated. Using a NCLS (Non negative constrained least squares) approach, contribution of specific molecules can be estimated at each point of spectral maps in order to deliver semi-quantitative …

In Vitro Label Free Screening Of Chemotherapeutic Drugs Using Raman Micro-Spectroscopy: Towards A New Paradigm Of Spectralomics., Zeineb Farhane, Haq Nawaz, Franck Bonnier, Hugh Byrne

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This overview groups some of the recent studies highlighting the potential application of Raman micro-spectroscopy as an analytical technique in preclinical development to predict drug mechanism of action and in clinical application as a companion diagnostic and in personalised therapy due to its capacity to predict cellular resistance and therefore to optimise chemotherapeutic treatment efficacy.

Notably, the anthracyclines, Doxorubicin and Actinomycin D, elicit similar spectroscopic signatures of subcellular interaction characteristic of the mode of action of intercalation. Although Cisplatin and Vincristine show markedly different signatures, at low exposure doses, their signatures at higher doses show marked similarities to those elicited …

Investigation Of Temperature Response Of Photopolymer Material Used For Holographic Sensor, Muhammad Irfan Dr, Tatsiana Mikulchyk Dr, Suzanne Martin Dr, Izabela Naydenova Prof

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Recently, functionalised photopolymer has emerged as a versatile recording material in the field of optical holography due to its novel characteristics and potential use in the development of holographic based sensors, and optical elements. This work describes the temperature response of a newly developed photopolymer, containing of a monomer Nisopropylacrylamide (NIPA) which under photopolymerisation forms a temperature sensitive polymer - Poly(Nisopropylacrylamide) (PNIPA). The photonic sensor was developed by holographic recording of volume phase transmission gratings in a self-processing NIPA-based polymer with a 532 nm laser beam. A 633 nm probe beam was used to monitor real time diffraction efficiency (DE) …

Disposable Printed Lateral Flow Electrochemical Immunosensors For Human Cardiac Troponin T, Eithne Dempsey, Dhanraj Rathod

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Here we report an electrochemical ELISA approach for cardiac Troponin T (cTnT) determination based on a lateral flow membrane with underlying screen printed electrodes (<;100 Ω /cm 2 ). The thick film transducer was modified with the anti-cardiac Troponin T antibody via physisorption and the electrochemical performance of the immunosensor was evaluated using cyclic voltammetry. The capture antibody coated immunoelectrode employed for electrochemical determination of Troponin T antigen used a sandwich assay format with horseradish peroxidase conjugated signaling antibodies held in the track of a lateral flow sensor strip. A simple two step procedure realized signal acquisition within <;20 min (total assay time). The lateral flow electrochemical immunosensor response resulted in a calibration curve with linear response (0-700 ng/ml cTnT) with limit of detection of 0.15 ng/ml.

Significance Of A Non-Thermal Plasma Treatment On Ldpe Biodegradation With Pseudomonas Aeruginosa, Laurence Scally, Miroslav Gulan, Lars Weigang, Vladimir Milosavljević, Patrick J. Cullen

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The use of plastics has spanned across almost all aspects of day to day life. Although their uses are invaluable, they contribute to the generation of a lot of waste products that end up in the environment and end up polluting natural habitats such as forests and the ocean. By treating low-density polyethylene (LDPE) samples with non-thermal plasma in ambient air and with an addition of ≈4% CO2, the biodegradation of the samples can be increased due to an increase in oxidative species causing better cell adhesion and acceptance on the polymer sample surface. It was, however, found that the …

A Comparison Of On-Line And Off-Line Bioaerosol Measurements At A Biowaste Site, Patrick Feeney, Santiago Fernández Rodríguez, Rafael Molina, Eoin Mcgillicuddy, Stig Hellebust, Michael Quirke, Shane Daly, David O'Connor, John Sodeau

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An air measurement campaign was carried out at a green-waste composting site in the South of Ireland during Spring 2016. The aim was to quantify and identify the levels of Primary Biological Aerosol Particles (PBAP) that were present using the traditional off-line, impaction/optical microscopy method alongside an on-line, spectroscopic approach termed WIBS (Wideband Integrated Bioaerosol Sensor), which can provide number concentrations, sizes and “shapes” of airborne PBAP in real-time by use of Light Induced Fluorescence (LIF). The results from the two techniques were compared in order to validate the use of the spectroscopic method for determining the releases of the …

Environmental Impact Assessment Of Pinaceae Airborne Pollen And Green Infrastructure Using Bim, Santiago Fernández-Rodríguez, Juan Pedro Cortés-Pérez, Paloma Prieto Muriel, Rafael Tormo-Molina, J. M. Maya-Manzano

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Urban air quality is a parameter that plays a major role in human health at the local scale. Consequently, in urban planning, the behavior and potential risk of allergenicity for some pollen grains coming from ornamental trees and green spaces surrounding newly built buildings, should be considered. This paper aims to study how pollen exposure, influenced by weather parameters, can be assessed and integrated in the designing and building of constructions as other component of air quality assessment beforehand, by using BIM. Based on a comparative aerobiological study at the height over a building (sampled by two traps at ground …

Robust, Bridge-Less Ion-Selective Electrodes With Significantly Reduced Need For Pre- And Post-Application Handling, Benjamin Schazmann, S. Demey, Z. Waqar Ali, M-S Plissart, E. Brennan, A. Radu

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We are demonstrating robust, single-layer ion-selective electrode (ISE) utilizing simple Ag/AgCl electrode as solid support without the need for intermediate polymer layer. We have created and chemically linked a family of imidazolium ionic liquids (ILs) with poly (vinyl chloride) (PVC) using click chemistry, resulting in hybrid materials with tunable characteristics. The resultant material inherently contains chloride ion thus offering the ability to stabilize interfacial potential. This allowed us to construct very simple, single-layer membranes with significantly reduced need for conditioning as an added bonus compared to traditional sensors. Chemical immobilization of ISE membrane components also led to extended lifetime as …

The Role Of The Hydrolysis And Zirconium Concentration On The Structure And Anticorrosion Performances Of A Hybrid Silicate Sol-Gel Coating, Maikki Cullen, Mary O’Sullivan, Aditya Madhan Kumar, Ahmad A. Sorour, Brendan Duffy, Mohamed Oubaha

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In sol-gel chemistry, hydrolysis is the key step in the formation of the reactive hydroxide groups that are responsible for the formation of inorganic networks via the occurrence of condensation reactions. Though previous studies have investigated the effect of the hydrolysis conditions on the structure of organically modified silicates (ormosils), no study, to our knowledge, has investigated this variable on the structure of hybrid materials prepared by combinations of an ormosil and a transition metal (TM). Here, we propose to investigate this effect in a hybrid material composed of 3-trimethoxysilylpropylmethacrylate and a zirconium complex. To also highlight the effects of …

A Novel Quantitative Electrochemical Method To Monitor Dna Double-Strand Breaks Caused By A Dna Cleavage Agent At A Dna Sensor, Anna Banasiak, John Cassidy, John Colleran

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Biosensors and Bioelectronics, Vol. 117

Comparison Of Fungal Spores Concentrations Measured With Wideband Integrated Bioaerosol Sensor And Hirst Methodology, S. Fernández-Rodríguez, R. Tormo-Molina, N. Lemonis, B. Clot, David O'Connor, John R. Sodeau

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The aim of this work was to provide both a comparison of traditional and novel methodologies for airborne spores detection (i.e. the Hirst Burkard trap and WIBS-4) and the first quantitative study of airborne fungal concentrations in Payerne (Western Switzerland) as well as their relation to meteorological parameters. From the traditional method -Hirst trap and microscope analysis-, sixty-three propagule types (spores, sporangia and hyphae) were identified and the average spore concentrations measured over the full period amounted to 4145 ± 263.0 spores/m3. Maximum values were reached on July 19th and on August 6th. Twenty-six spore types reached average levels above …

The Janus-Faced Chromophore: A Donor-Acceptor Dyad With Dual Performance In Photon Up-Conversion, Natalia Kiseleva, Mikhail Filatov, Michael Oldenburg, Dimitry Busko, Marius Jakoby, Ian Howard, Bryce Richards, Mathias Senge, Sergey Borisov, Andrey Turshatov

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An electron donor-acceptor dyad based on BODIPY (acceptor) and anthracene (donor) plays either the role of sensitizer or emitter in triplet-triplet annihilation photon up-conversion (TTA-UC). This Janus-like behavior was achieved via altering the relative ordering of charge-transfer and local excited state energies in the dyad through the polarity of TTA-UC media.

Synthesis, Characterisation And Dna Intercalation Studies Of Regioisomers Of Ruthenium (Ii) Polypyridyl Complexes, Laura Perdisatt, Samar Moqadasi, Luke O'Neill, Gary Hessman, Alessandra Ghion, Muhammad Qasim Mushtaq Warraich, Alan Casey, Christine O'Connor

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Regioisomers of the functional group of the main ligand (L) on a series of [Ru(phen)2L]2+and [Ru(bpy)2L]2+ complexes, where phen is 1,10 phenanthroline and bpy is 2,2′-bipyridine, were synthesised to investigate the interaction with deoxyribonucleic acid (DNA) as potential therapeutics. UV–Vis binding titrations, thermal denaturation and circular dichroism were used to evaluate their interaction with DNA. The conclusions indicated the significance of the auxiliary ligand; especially 1,10-phenanthroline has on the binding constants (Kb). The systematic variation of auxiliary ligand(phen or bpy), and polypyridyl ligand (4-(1H-Imidazo[4,5-f][1,10]phenanthrolin-2-yl)benzonitrile (CPIP), 2-(4-formylphenyl)imidazo[4,5-f] [1,10] phenanthroline (FPIP), 2-(4-bromophenyl)imidazo[4,5-f][1,10]phenanthroline (BPIP) and 2-(4-nitrophenyl)imidazo[4,5-f] [1,10] phenanthroline (NPIP), split in terms of …

Targeting The Folate Receptor: Improving Efficacy In Inorganic Medicinal Chemistry, Pauraic Mccarron, Aisling Crowley, Denis O'Shea, Malachy Mccann, Orla L. Howe, Mary Hunt, Michael Devereux

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The discovery of the high-affinity, high-specificity folate receptor in mamalian kidney cells, coupled with the ability of folate to enter cells by folate receptor-mediated endocytosis and the subsequent elucidation of the folate receptor’s overexpression in specific cancer cell types; heralded the arrival of the area of chemotherapeutic folate targeting. The application of purely organic folate-based small-molecule drug conjugates that selectively target the folate receptor, which is over expressed in several diseases such as cancer, is well established. The application of inorganic folate-targeted drugs offers significant potential to expand and enhance this therapeutic approach. From the data made available to date, …

Chemical Modifications Of Lipids And Proteins By Nonthermal Food Processing Technologies, Juan M. PéRez-AndréS, CléMentine Charoux, Patrick J. Cullen, Brijesh K. Tiwari

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A range of nonthermal techniques have demonstrated process efficacy in ensuring product safety, extension of shelf life, and in general a retention of key quality attributes. However, various physical, chemical and biochemical effects of nonthermal techniques on macro and micro nutrients are evident, leading to both desirable and undesirable changes in food products. The objective of this review is to outline the effects of nonthermal techniques on food chemistry and the associated degradation mechanisms with the treatment of foods. Oxidation is one of the key mechanisms responsible for undesirable effects induced by nonthermal techniques. Degradation of key macromolecules largely depends …

Unprecedented In Vitro Antitubercular Activitiy Of Manganese(Ii) Complexes Containing 1,10- Phenanthroline And Dicarboxylate Ligands: Increased Activity, Superior Selectivity, And Lower Toxicity In Comparison To Their Copper(Ii) Analogs, Pauraic Mccarron, Malachy Mccann, Michael Devereux, Kevin Kavanagh, Ciaran M. Skerry, Petros C. Karakousis, Ana Carolina Aor, Thaís P. Mello, Dos Santos, André Luis Souza Dos Santos, André Luis Souza, Débora Leite Campos, Fernando R. Pavan

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Mycobacterium tuberculosis is the etiologic agent of tuberculosis. The demand for new chemotherapeutics with unique mechanisms of action to treat (multi)resistant strains is an urgent need. The objective of this work was to test the effect of manganese(II) and copper(II) phenanthroline/dicarboxylate complexes against M. tuberculosis. The water-soluble Mn(II) complexes, [Mn2(oda)(phen)4(H2O)2][Mn2(oda)(phen)4(oda)2]·4H2O (1) and ([Mn(3,6,9-tdda)(phen)2]·3H2O·EtOH)n (3) (odaH2 = octanedioic acid, phen = 1,10-phenanthroline, tddaH2 = 3,6,9-trioxaundecanedioic acid), and water-insoluble complexes, [Mn(ph)(phen)(H2O)2] (5), [Mn(ph)(phen)2(H2O)]·4H2O (6), [Mn2(isoph)2(phen)3]·4H2O (7), ([Mn(phen)2(H2O)2])2(isoph)2(phen)·12H2O (8) and [Mn(tereph)(phen)2]·5H2O (9) (phH2 = phthalic acid, isophH2 = isophthalic acid, terephH2 = terephthalic acid), robustly inhibited the viability of M. tuberculosis strains, H37Rv …

Antifungal Potential Of Copper(Ii), Manganese(Ii) And Silver(I) 1,10-Phenanthroline Chelates Against Multidrug-Resistant Fungal Species Forming The Candida Haemulonii Complex: Impact On The Planktonic And Biofilm Lifestyles, Rafael M. Gandra, Pauraic Mc Carron, Mariana F. Fernandes, Lívia S. Ramos, Thaís P. Mello, Ana Carolina Aor, Marta H. Branquinha, Malachy Mccann, Michael Devereux, André L. S. Santos

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Candida haemulonii, Candida haemulonii var. vulnera and Candida duobushaemulonii, which form the C. haemulonii complex, are emerging etiologic agents of fungal infections known to be resistant to the most commonly used antifungals. The well-established anti-Candida potential ofmetal complexes containing 1,10-phenanthroline (phen) ligands encouraged us to evaluate different copper(II), manganese(II), and silver(I) phen chelates for their ability to inhibit planktonic growth and biofilm of C. haemulonii species complex. Two novel coordination complexes, {[Cu(3,6,9-tdda)(phen)2].3H2O.EtOH}n and [Ag2(3,6,9-tdda)(phen)4].EtOH (3,6,9-tddaH2 = 3,6,9-trioxaundecanedioic acid), were synthesized in a similar fashion to the other, previously documented, sixteen copper(II), manganese(II), and silver(I) chelates employed herein. Three isolates of …

Formulation, Characterisation And Stability Assessment Of A Food Derived 1 Tripeptide, Leucine-Lysine-Proline Loaded Chitosan Nanoparticles, Minna Khalid Danish, Giuliana Vozza, Hugh Byrne, Jesus Maria Frias, Sinead Ryan

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The chicken or fish derived tripeptide, Leucine-Lysine-Proline (LKP), inhibits the Angiotensin Converting Enzyme and may be used as an alternative treatment for pre-hypertension. However, it has low permeation across the small intestine. The formulation of LKP into a nanoparticle (NP) has the potential to address this issue. LKP-loaded NPs were produced using an ionotropic gelation technique, using chitosan (CL113). Following optimisation of unloaded NPs, a mixture amount design was constructed using variable concentration of CL113 and tripolyphosphate at a fixed LKP concentration. Resultant particle sizes ranged from 120-271 nm, zeta potential values from 29-37 mV and polydispersity values from 0.3-0.6. …

Solid-Phase Peptide Synthesis Of Analogues Of The N-Terminus A-Ring Fragment Of The Lantibiotic Nisin: Replacements For The Dehydroalanine (Dha) Residue At Position 5 And The First Incorporation Of A Thioamide Residue, Kim Manzor, Keith Ó Proinsias, Fintan Kelleher

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A number of A-ring analogues of the lantibiotic nisin, containing replacements for the Dha at position 5, have been successfully prepared by solid-phase peptide synthesis. The Dha replacements include glycine, alanine, phenylalanine, serine and 1-aminocyclopropyl carboxylic acid (ACCa). The incorporation of a thioamide-isoleucine residue at position 4 is also described and is the first report of the preparation of a lantibiotic ring fragment containing a thioamide link.

Conformational Studies Of Gram-Negative Bacterial Quorum Sensing 3-Oxo N-Acyl Homoserine Lactone Molecules, Darren Crowe, Alan Nicholson, Adrienne Fleming, Ed Carey, Goar Sanchez-Sanz, Fintan Kelleher

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In their ¹H NMR spectra in CDCl₃ 3-oxo-N-acyl homoserine lactones (OHLs) show significant downfield chemical shifts of the amide N-H proton when compared to the parent N-acyl homoserine lactones (AHLs). NMR spectroscopic and DFT calculation studies have shown that this is most likely due to the presence of a stabilising intramolecular H-bond from the N-H to the 3-oxo group. The ¹H NMR spectra also show evidence for the enol tautomers and that the amount of enol present for a range of OHLs is 4.1-4.5% in CDCl₃ and 6.5-7.2% in CD₃CN. In …

Industrial Grade 2d Molybdenum Disulphide (Mos2): An In-Vitro Exploration Of The Impact On Cellular Uptake, Cytotoxicity, And Inflammation, Caroline Moore, Hugh Byrne, Jonathan N. Coleman, Yuri Volkov, Jennifer Mcintyre

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The recent surge in graphene research, since its liquid phase monolayer isolation and characterization in 2004, has led to advancements which are accelerating the exploration of alternative 2D materials such as molybdenum disulphide (MoS2), whose unique physico-chemical properties can be exploited in applications ranging from cutting edge electronic devices to nanomedicine. However, to assess any potential impact on human health and the environment, the need to understand the bio-interaction of MoS2 at a cellular and sub-cellular level is critical. Notably, it is important to assess such potential impacts of materials which are produced by large scale production techniques, rather than …

Enhancement Of Dielectric Properties With The Addition Of Bromine And Dopamine Modified Barium Titanate Particles To Silicone Rubber, Liang Jiang, David Kennedy, Stephen Jerrams, Tony Betts

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Dual-coated barium titanate (BT) particles were prepared using dopamine (DP) in conjunction with bromine (Br) in order to enhance the dielectric constant of silicone rubber (SR) composites containing evenly distributed BT particles. The results showed that both DP and Br were deposited on the BT particles. The dielectric constant of the SR/BT composite was significantly increased from 3.6 to 4.7 at 1 kHz with the addition of BT modified with dopamine (DP–BT). Moreover, the dielectric constant further rose to 4.9 at 1 kHz when the DP–BT particle was grafted with bromine (Br–DP–BT).

Validation Of A Membrane Touch Biosensor For The Qualitative Detection Of Igg Class Antibodies To Herpes Simplex Virus Type 2, Tony Loughman, Baljit Singh, Brian Seddon, Philip Noone, Padmanabhan Santhosh

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A novel type of biosensor was assessed for application to the qualitative determination of circulating antibodies to herpes simplex virus type 2 (HSV-2). The device utilises a high activity HSV-2 type specific gG2 antigen for antibody capture and commercially available ELISA reagents. The study compares the diagnostic performance of a prototype HSV-2 biochip to well-established in vitro tests routinely applied in clinical procedures. A panel of human serum samples (n = 60) previously characterised for HSV-2 serological status using the DiaSorin LIAISON® HSV-2 chemiluminescent immunoassay were assayed on the HSV-2 biochip and the Focus Diagnostics HerpeSelect® 2 ELISA IgG kit …

Isolation And Spectroscopic Characterization Of Zn(Ii), Cu(Ii), And Pd(Ii) Complexes Of 1,3,4-Thiadiazole-Derived Ligand, Dariusz Karcz, Arkadiusz Matwijczuk, Bozena Boron, Bernadette Creaven, Leszek Fiedor, Andrzej Niewiadomy, Mariusz Gagos

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A series of complexes incorporating Zn(II), Cu(II), and Pd(II) ions, and 4-(5-heptyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (L1) as model ligand, was synthesized in order to examine the nature of potential interactions between biologically active ligands, 1,3,4-thiadiazoles and metal ions with proven biological relevance. The structures of the compounds isolated were characterized using a number of spectroscopic methods including IR, Uv–vis, AAS, steady state and time-resolved fluorescence (TRF). The results obtained suggest that the L1-Zn(II) and L1-Pd(II) complexes consist of one molecule of L1 and one acetate ion acting as ligands, while the L1-Cu(II) complex adapts a 2:1 (L1: metal) stoichiometry. The coordination of L1 …

A Rational Design Of A Selective Inhibitor For Kv1.1 Channels Prevalent In Demyelinated Nerves That Improves Their Impaired Axonal Conduction, Ahmed Al-Sabi, Declan Daly, Patrick Hoefer, Gemma K. Kinsella, Charles Metais, Mark Pickering, Caroline Herron, Seshu Kumar Kaza, Kieran Nolan, J. Oliver Dolly

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K+ channels containing Kv1.1 α subunits, which become prevalent at internodes in demyelinated axons, may underlie their dysfunctional conduction akin to muscle weakness in multiple sclerosis. Small inhibitors were sought with selectivity for the culpable hyper-polarizing K+ currents. Modeling of interactions with the extracellular pore in a Kv1.1-deduced structure identified diaryldi(2-pyrrolyl)methane as a suitable scaffold with optimized alkyl ammonium side chains. The resultant synthesized candidate [2,2′-((5,5′(di-p-topyldiaryldi(2-pyrrolyl)methane)bis(2,2′carbonyl)bis(azanediyl)) diethaneamine·2HCl] (8) selectively blocked Kv1.1 channels (IC50 ≈ 15 μM) recombinantly expressed in mammalian cells, induced a positive shift in the voltage dependency of K+ current activation, and slowed its kinetics. It …

Quantification Of Copper Content With Laser Induced Breakdown Spectroscopy As A Potential Indicator Of Offal Adulteration In Beef, Maria Piedad Casado-Gavalda, Yash Dixit, David Geulen, Raquel Cama-Moncunill, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Patrick J. Cullen, Carl Sullivan

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Laser induced breakdown spectroscopy (LIBS) is an emerging technique in the field of food analysis which provides various advantages such as minimal sample preparation, chemical free, rapid detection, provision of spatial information and portability. In this study, LIBS was employed for quantitative analysis of copper content in minced beef samples spiked with beef liver over three independent batches. Copper content was determined with graphite furnace atomic absorption spectroscopy (GFAAS) in order to obtain reference values for modelling. Partial least square regression (PLSR) was performed to build a calibration and validation model. A calibration model with a high Rcv2 of 0.85 …

Quantification Of Trace Metals In Infant Formula Premixes Using Laser-Induced Breakdown Spectroscopy, Raquel Cama-Moncunill, Maria Piedad Casado-Gavalda, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Yash Dixit, Patrick J. Cullen, Carl Sullivan

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Infant formula is a human milk substitute generally based upon fortified cow milk components. In order to mimic the composition of breast milk, trace elements such as copper, iron and zinc are usually added in a single operation using a premix. The correct addition of premixes must be verified to ensure that the target levels in infant formulae are achieved. In this study, a laser-induced breakdown spectroscopy (LIBS) system was assessed as a fast validation tool for trace element premixes. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers real-time analyses, little to no sample preparation and …

Quantification Of Rubidium As A Trace Element In Beef Using Laser Induced Breakdown Spectroscopy, Yash Dixit, Maria Piedad Casado-Gavalda, Raquel Cama-Moncunill, Xavier Cama-Moncunill, Patrick J. Cullen, Carl Sullivan

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This study evaluates the potential of laser induced breakdown spectroscopy (LIBS) coupled with chemometrics to develop a quantification model for rubidium (Rb) in minced beef. A LIBSCAN 150 system was used to collect LIBS spectra of minced beef samples. Beef liver was used to spike the Rb levels in minced beef. All samples were dried, powdered and pelleted using a hydraulic press. Measurements were conducted by scanning 100 different locations with an automated XYZ sample chamber. Partial least squares regression (PLSR) was used to develop the calibration model, yielding a calibration coefficient of determination (Rc2) of 0.99 and a root …

An Ionic Liquid Based Sensor For Diclofenac Determination In Water, Emma Brennan, Pauline Futvoie, John Cassidy, Benjamin Schazmann

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This paper details a miniaturised, solid state ion-selective electrode selective for diclofenac. The sensor comprises a novel ionic liquid electroactive material – an imidazolium–diclofenac ion associate. The ion associate is present in a plasticised poly(vinyl chloride) (PVC) membrane on planar carbon electrodes, with an intermediate poly(3,4-ethylenedioxythiophene) layer. The sensitivity and selectivity of the sensor were determined using chronopotentiometric methods. In response to diclofenac, a slope of −53.3 ± 3.6 mV/dec was observed. A limit of detection of 2.90 × 10−3 g L−1 is reported, with a linear range of 3.18 × 10−3 g L−1 to 3.18 g L−1. …

Effects Of Ommt On The Aging Behaviors Of Halogen-Antimony Flame-Retarded Lgfpa6 Composites: Flammability And Thermal Degradation Kinetics, Xiaoling Zuo, Haishuo Song, Huiju Shao, Minh Hang Au, Tao Wei, Jianbing Guo

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After a long-term thermo-oxidative exposure, compared to the long-glass-fiber reinforced polyamide 6 composite containing halogen-antimony flame retardants (FR/LGFPA6), substitution of a certain content of flame retardants with organo-modified montmorillonite (OMMT) was found to positively affect the FR/LGFPA6 composite in some cases (i.e. flammability and thermal degradation kinetics). The aged OMMT/FR/LGFPA6 composite not only was less flammable but also behaved better in the formation of char residues. All the calculated apparent activation energy obtained by the methods of Friedman, Flynn-Wall-Ozawa and Coats- Redfern in a dynamic measurement showed an obvious increase for the OMMT/FR/LGFPA6 composite after aging, a theoretical evidence for …