A functional peptide-mediated colorimetric assay for mercury ion based on dual-modified gold nanoparticles.

In the work, a rapid and accurate biosensor for mercury ions (Hg2+) was constructed, with which aggregation of dual-modified (DGPFHR- and CALNN-) gold nanoparticles (D/C-AuNPs) could be triggered by the high specificity of peptides to Hg2+. The given peptide DGPFHR possesses great capability of capturing Hg2+, accompanied by the conformational folding. Under the circumstances, D/C-AuNPs were employed as the detection probes to accomplish the quantitative analysis of Hg2+. This is primarily because the specific Hg2+-induced folding of peptides reduces the electrostatic repulsion and steric hindrance, thus accelerating the AuNPs aggregation. The principle and application potential of this proposal was proved by evidence. And the results demonstrated that Hg2+ ions could be selectively detected as low as 28 nM with a linear range of 100-800 nM. In consideration of superior simplicity, selectivity, accuracy and stability, the protocol was advantageous over other projects in practical measurement of various water samples.

Vacuum Ultraviolet Absorption Spectroscopy Analysis of Breath Acetone Using a Hollow Optical Fiber Gas Cell.

Human breath is a biomarker of body fat metabolism and can be used to diagnose various diseases, such as diabetes. As such, in this paper, a vacuum ultraviolet (VUV) spectroscopy system is proposed to measure the acetone in exhaled human breath. A strong absorption acetone peak at 195 nm is detected using a simple system consisting of a deuterium lamp source, a hollow-core fiber gas cell, and a fiber-coupled compact spectrometer corresponding to the VUV region. The hollow-core fiber functions both as a long-path and an extremely small-volume gas cell; it enables us to sensitively measure the trace components of exhaled breath. For breath analysis, we apply multiple regression analysis using the absorption spectra of oxygen, water, and acetone standard gas as explanatory variables to quantitate the concentration of acetone in breath. Based on human breath, we apply the standard addition method to obtain the measurement accuracy. The results suggest that the standard deviation is 0.074 ppm for healthy human breath with an acetone concentration of around 0.8 ppm and a precision of 0.026 ppm. We also monitor body fat burn based on breath acetone and confirm that breath acetone increases after exercise because it is a volatile byproduct of lipolysis.

Simultaneous quantitation of two direct acting hepatitis C antivirals (sofosbuvir and daclatasvir) by an HPLC-UV method designated for their pharmacokinetic study in rabbits.

Sofosbuvir (SOF) and daclatasvir (DCS) are novel, recently developed direct acting antiviral agents characterized by potent anti-hepatitis C virus action. A fast and efficient HPLC-UV method was developed, validated and applied for simultaneous determination of SOF and DCS in pharmaceutical formulations and biological fluids based on coupling liquid-liquid extraction with ultrasound and dual wavelength detection at λmax; 260 and 313 nm for SOF and DCS, respectively. This approach provided simple, sensitive, specific and cost-effective determination of the SOF-DCS mixture with good recoveries of the analytes from plasma. Analytes were separated within 7 min on C18 analytical column with acetonitrile-10 mM acetate buffer of pH 5.0 at a flow rate of 1.0 mL min-1. The linear ranges were 1-20 µg mL-1 for SOF and 0.6-6 µg mL-1 for DCS with correlation coefficients ≥0.9995. The detection limits in spiked rabbit plasma were 0.20 and 0.19 µg mL-1 for SOF and DCS, respectively. The method was validated according to ICH and US-FDA guidelines. Finally, the method was successfully applied for simultaneous pharmacokinetic studies of SOF and DCS in rabbits using rofecoxib as internal standard.

UV-vis Imaging of Piroxicam Supersaturation, Precipitation, and Dissolution in a Flow-Through Setup.

Evaluation of drug precipitation is important in order to address challenges regarding low and variable bioavailability of poorly water-soluble drugs, to assess potential risk of patient safety with infusion therapy, and to explore injectable in situ suspension-forming drug delivery systems. Generally, drug precipitation is assessed in vitro through solution concentration analysis methods. Dual-wavelength UV-vis imaging is a novel imaging technique that may provide an opportunity for simultaneously monitoring changes in both solution and solid phases during precipitation. In the present study, a multimodal approach integrating UV-vis imaging, light microscopy, and Raman spectroscopy was developed for characterization of piroxicam supersaturation, precipitation, and dissolution in a flow-through setup. A solution of piroxicam dissolved in 1-methyl-2-pyrrolidinone was injected into a flowing aqueous environment (pH 7.4), causing piroxicam to precipitate. Imaging at 405 and 280 nm monitored piroxicam concentration distributions during precipitation and revealed different supersaturation levels dependent on the initial concentration of the piroxicam solution. The combination with imaging at 525 nm, light microscopy, and Raman spectroscopy measurements demonstrated concentration-dependent precipitation and the formation, growth, and dissolution of individual particles. Results emphasize the importance of the specific hydrodynamic conditions on the piroxicam precipitation. The approach used may facilitate comprehensive understanding of drug precipitation and dissolution processes and may be developed further into a basic tool for formulation screening and development.

Analysis of cannabinoids in commercial hemp seed oil and decarboxylation kinetics studies of cannabidiolic acid (CBDA).

Hemp seed oil from Cannabis sativa L. is a very rich natural source of important nutrients, not only polyunsaturated fatty acids and proteins, but also terpenes and cannabinoids, which contribute to the overall beneficial effects of the oil. Hence, it is important to have an analytical method for the determination of these components in commercial samples. At the same time, it is also important to assess the safety of the product in terms of amount of any psychoactive cannabinoid present therein. This work presents the development and validation of a highly sensitive, selective and rapid HPLC-UV method for the qualitative and quantitative determination of the main cannabinoids, namely cannabidiolic acid (CBDA), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), tetrahydrocannabinol (THC), cannabinol (CBN), cannabigerol (CBG) and cannabidivarin (CBDV), present in 13 commercial hemp seed oils. Moreover, since decomposition of cannabinoid acids generally occurs with light, air and heat, decarboxylation studies of the most abundant acid (CBDA) were carried out in both open and closed reactor and the kinetics parameters were evaluated at different temperatures in order to evaluate the stability of hemp seed oil in different storage conditions.

Ultrasensitive Detection of α-Fetoprotein by Total Internal Reflection Scattering-Based Super-Resolution Microscopy for Superlocalization of Nano-Immunoplasmonics.

Superlocalization of immunoplasmonic nanotags on antibody-bound gold-nanoislands (GNIs) along the x and y coordinates was determined using total internal reflection scattering-based super-resolution microscopy (TIRS-SRM) at subdiffraction limit resolution. Individual immunoplasmonic nanotags (20 nm silver nanoparticles) and 100 nm GNIs were selectively acquired in the evanescent field layer by wavelength-dependent plasmonic scattering using two illumination lasers (405 and 635 nm, respectively). α-Fetoprotein (AFP), a liver cancer-related model protein, was immobilized as a target molecule on the GNI arrays. The centroid position of a localized immunoplasmonic nanotag on the GNI was resolved at less than 10 nm of spatial resolution by applying 2D Gaussian fitting to its point spread function. This method showed enhanced sensitive quantification with a limit of detection (LOD) of 7.04 zM (1-2 molecules of AFP/GNI), which was 100-5000000000 times lower than detection limits obtained with previous AFP detection methods. Furthermore, the method was also successfully applied to quantify AFP molecules at the single-molecule level in human serum samples. The wavelength-dependent TIRS-SRM method was demonstrated to be an effective tool for superlocalizing individual protein molecules and interactions in nanoscale regions and was a reliable method for the ultrasensitive quantitative detection of disease-related protein molecules as a nanosensor and for diagnosis at the single-molecule level.

Label-free amino acid detection based on nanocomposites of graphene oxide hybridized with gold nanoparticles.

Nanocomposites of graphene oxide and gold nanoparticles (GO/GNPs) were synthesized for label-free detections of amino acids. Interactions between the composites and amino acids were investigated by both naked-eye observation and optical absorption spectroscopy. The GO/GNPs composites displayed apparent color changes and absorption spectra changes in presences of amino acids including glutamate, aspartate, and cysteine. The interaction mechanisms of the composites and amino acids were discussed and explored with sulfhydryl groups and non-α-carboxylic groups on the amino acids. Sensing properties of the composites were tested, while pure gold particles were used as the control. The results suggested that the GO/GNPs composites had better linearity and stability in dose-dependent responses to the amino acids than those of the particles, especially in detections for acidic amino acids. Therefore, the nanocomposites platform can provide a convenient and efficient approach for label-free optical detections of important molecules such as amino acids.

Métodos indicativos de estabilidade para determinação do besilato de anlodipino, nifedipino e nimodipino considerados inibidores do canal de cálcio / Determination of calcium channel blockers amlodipine besylate, nifedipine and nimodipine by stability assays

A hipertensão é uma doença crônica não transmissível e mais freqüente na população sendo o principal fator de risco para complicações cardiovasculares, tais como acidente vascular cerebral e infarto agudo do miocárdio. Na presente pesquisa estão sendo estudados os fármacos utilizados no tratamento da hipertensão mais especificamente, os bloqueadores do canal de cálcio do grupo diidropiridínicos: besilato de anlodipino, nifedipino e nimodipino. O objetivo desse trabalho foi verificar a estabilidade intrínseca dos fármacos besilato de anlodipino, nifedipino e nimodipino, para isto foram utilizadas as seguintes técnicas: testes indicativos de estabilidade utilizando as técnicas de espectrofotometria na região do Ultravioleta/Visível (UV/VIS) e Cromatografia em fase Líquida de Alta Eficiência (CLAE). Termogravimetria/ Termogravimetria Derivada (TG/DTG), Calorimetria Exploratória Diferencial (DSC), Difração de Raios X (DRX), Espectroscopia de absorção na região do Infravermelho com Transformada de Fourier (FTIR) e Microscopia Eletrônica de Varredura (MEV). Para o fármaco besilato de anlodipino (AB) pelo método de degradação forçada, analisado por espectrofotometria no UV/VIS, as condições para a análise espectrofotométrica foram metanol e água a uma proporção de (5:45 v/v) e a segunda diluição com água. A leitura foi efetuada a 364,4nm. A linearidade foi estabelecida na faixa de 40,0-65,0 µg/mL e o coeficiente de correlação foi (r) 0,9992. O método cromatográfico, mostrou o diferente comportamento das substâncias nifedipino e nimodipino diante dos meios básicos, ácido, neutro e oxidativo. As condições para a substância nifedipino foram coluna LiChrospher®100 RP-18 (5µm) Merck® fase móvel constituída por metanol e água (45:55v/v), fluxo 1.0 mL/min, tempo de retenção 5,1min, detecção UV a 234nm e vazão de 1.0 mL/min. Foi obtida uma linearidade no intervalo de 5.0-55.0 µg/mL coeficiente de correlação (r) =0,9964. E para a substância nimodipino foram coluna LiChrospher®100 RP-18 (5µm) Merck® fase móvel constituída por acetonitrila e água (55:45v/v), fluxo 1.0mL/min, tempo de retenção 5,8 min, detecção UV a 235 nm e vazão de 1.0mL/min. Foi obtida uma linearidade no intervalo de 5.0-55.0 µg/mL coeficiente de correlação (r) =0,9964. Os resultados obtidos das curvas TG/DTG e DSC mostraram o perfil da decomposição térmica das substâncias estudadas pela Calorimetria Exploratória Diferencial. A análise dos resultados de DRX e DSC mostraram que não há evidências de polimorfismo nessas substâncias. No entanto nas análises de Espectroscopia de absorção na região do infravermelho com Transformada de Fourier (FTIR) não foram encontradas diferenças significativas na matéria-prima e no padrão de referência. As análises de MEV permitiram observar a cristalinidade das substâncias estudadas

Hypertension is the most frequent non-communicable chronic disease in the population being the main factor of risk for cardiovascular complications, such as stroke and acute myocardial infarction. In this work, active pharmaceutical ingredients used to treat hypertension were studied, more specifically the blockers calcium channel dihydropyridine group: amlodipine besylate, nifedipine and nimodipine. The aim of this study was to determine the intrinsic stability of amlodipine besylate, nifedipine and nimodipine. For this purpose the following stability test techniques were used: UV/VIS spectrophotometry and chromatography Net phase High Performance. Thermogravimetry/Derivative Thermogravimetry (TG/ DTG), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), Fourier Transformed Infrared absorption (FTIR) and Scanning Electron Microscopy (MEV). For drug amlodipine besylate (AB) by forced degradation method analyzed by spectrophotometry UV/VIS spectrophotometric conditions for the analysis were methanol and water at a ratio (5:45v/v) and the second dilution with water. The reading was made at 364,4nm. The linearity was established in the range of 40.0 to 65.0 mg/mL and the correlation coefficient was (r) 0.9992. The chromatographic method showed different behavior of nifedipine and nimodipine substances on the basic means, acid, neutral and oxidative. The conditions for nifedipine were LiChrospher®100 RP-18 column (5µm) Merck® mobile phase consisting of methanol and water (45:55v/v), flow 1.0 mL/min, retention time 5,1min, UV detection at 234 nm and flow of 1.0 mL/min. Linearity was obtained within the range of 5.0-55.0 mg/mL correlation coefficient (r) = 0.9964. And for nimodipine the parameters were: LiChrospher®100 RP-18 column (5µm) Merck® mobile phase consisted of acetonitrile: water (55:45v/v), flow 1.0 mL/min, retention time 5,8min, UV detection at 235nm and flow of 1.0 mL/min. The linearity was obtained within the range of 5.0- 55.0 mg/mL correlation coefficient (r) = 0.9964. The results of TG/DTG and DSC curves presented the profile of the thermal decomposition of the substances studied by DSC. The results of XRD and DSC presented no evidence of polymorphism in these analyzes, however, according to analyzes of absorption spectroscopy in the infrared (FTIR) there were no significant differences in the raw materials and standard reference. SEM analyzes allowed to observe the crystallinity of the studied substances

Implementation of real-time identification analysis and quantification of chemotherapies preparations with a Multispec(®) analyser.

Post-production analytic control of chemotherapies preparations remains a challenge for hospital pharmacists. Indeed, to be feasible, this control needs to be reliable, fast and easy to implement and to use on real life. This is particularly true for teams not familiar with analytic methods. The Multispec(®) analyser has been specially manufactured for that purpose. After several years of daily use, we wanted to focus on its implementation, abilities and defects that should be corrected on the next analyser. Upon 24 months, 23,350 samples have been analysed. Four percent have been rejected on the first analysis, and finally only 0.37% with another sample after homogenization. Eighty-six preparations have been done another time for non-conformity purpose. Difficulties of implementation were in particular on anthracyclins, oxazophosphorins and monoclonal antibodies. However, compared to liquid chromatography for example, the ultraviolet and infrared combination allows a large number of drugs to be recognized and quantified fastly. As a conclusion this analyser is quite helpful and gives a serious alternative to post-production analytic control for chemotherapies preparations. Some points should however be improved, probably on the next analyser, for instance the sample volume necessary for analysis.

High-throughput, high-resolution Echelle deep-UV Raman spectrometer.

We constructed an ultrahigh-throughput, high-resolution ultraviolet (UV) Raman spectrograph that utilizes a high-efficiency filter-stage monochromator and a high-dispersion Echelle spectrograph. The spectrograph utilizes a total of six mirrors and two gratings, with an overall efficiency at 229 nm of ~18%. The limiting resolution of our spectrometer is 0.6 cm⁻¹ full width half-maximum (FWHM), as measured for 229 nm Rayleigh scattering. Use of a 1 mm-wide entrance slit gives rise to an approximately 10 cm⁻¹ FWHM resolution at 229 nm. The ultrahigh spectrograph throughput enables ultrahigh signal-to-noise ratio, deep UV Raman spectra that allow us to monitor <1% changes in peptide bond composition. The throughput is measured to be 35-fold greater than conventional deep UV Raman spectrometers.

Sensitive and selective detection of trace copper in standard alloys, food and biological samples using a bulk optode based on N,N'-(4,4'-ethylene biphenyl) bis(3-methoxy salicylidine imine) as neutral carrier.

In this paper, an optical sensing film has been proposed for sensitive determination of copper (ІІ) ion in aqueous solutions. The copper sensing membrane was prepared by incorporating N,N'-(4,4'-ethylene biphenyl) bis(3-methoxy salicylidine imine) as ionophore in the plasticized PVC membrane containing bis(2-ethylhexyl) sebacate (DOS) as plasticizer. This proposed membrane works on the basis of a cation-exchange mechanism and shows a significant absorbance signal change on exposure to acetate buffer solution of pH 4.0 containing copper ion. The proposed sensing film displays a linear range of 0.01-32.0 µg mL(-1) with a limit of detection 0.008 µg mL(-1). Moreover, upon the introduction of a negatively charged lipophilic additive (oleic acid) into the membrane, the optode displayed enhanced sensitivity. In addition, satisfactory analytical sensing characteristics for determining copper (II) ion were obtained in terms of the selectivity, stability and reproducibility. The response time of the optode was less than 3 min, depending on the concentration of Cu(ІІ) ions. The optode membrane has been applied to determine Cu(II) in various real samples.

He I ultraviolet photoelectron spectroscopy of benzene and pyridine in supersonic molecular beams using photoelectron imaging.

We performed He I ultraviolet photoelectron spectroscopy (UPS) of jet-cooled aromatic molecules using a newly developed photoelectron imaging (PEI) spectrometer. The PEI spectrometer can measure photoelectron spectra and photoelectron angular distributions at a considerably higher efficiency than a conventional spectrometer that uses a hemispherical energy analyzer. One technical problem with PEI is its relatively high susceptibility to background electrons generated by scattered He I radiation. To reduce this problem, we designed a new electrostatic lens that intercepts background photoelectrons emitted from the repeller plate toward the imaging detector. An energy resolution (ΔE/E) of 0.735% at E = 5.461 eV is demonstrated with He I radiation. The energy resolution is limited by the size of the ionization region. Trajectory calculations indicate that the system is capable of achieving an energy resolution of 0.04% with a laser if the imaging resolution is not limited. Experimental results are presented for jet-cooled benzene and pyridine, and they are compared with results in the literature.

Clinical research device for ovarian cancer detection by optical spectroscopy in the ultraviolet C-visible.

Early detection of ovarian cancer could greatly increase the likelihood of successful treatment. However, present detection techniques are not very effective, and symptoms are more commonly seen in later stage disease. Amino acids, structural proteins, and enzymatic cofactors have endogenous optical properties influenced by precancerous changes and tumor growth. We present the technical details of an optical spectroscopy system used to quantify these properties. A fiber optic probe excites the surface epithelium (origin of 90% of cases) over 270 to 580 nm and collects fluorescence and reflectance at 300 to 800 nm with four or greater orders of magnitude instrument to background suppression. Up to four sites per ovary are investigated on patients giving consent to oophorectomy and the system's in vivo optical evaluation. Data acquisition is completed within 20 s per site. We illustrate design, selection, and development of the components used in the system. Concerns relating to clinical use, performance, calibration, and quality control are addressed. In the future, spectroscopic data will be compared with histological biopsies from the corresponding tissue sites. If proven effective, this technique can be useful in screening women at high risk of developing ovarian cancer to determine whether oophorectomy is necessary.

Identification of the position of mono-O-glucuronide of flavones and flavonols by analyzing shift in online UV spectrum (lambdamax) generated from an online diode array detector.

The beneficial pharmacological effects of flavonoids such as chemoprevention against cancer, aging, and heart diseases are severely limited due to their extensive in vivo glucuronidation by UDP-glucuronosyltransferases (UGTs). UGTs showed regiospecificity (i.e., position preference) in the glucuronidation of the flavonoids based on the substrate's chemical structure. In this paper, glucuronide(s) of 36 flavones and flavonols were generated using an in vitro glucuronidation reaction. UPLC/MS/MS was used to confirm the degree (mono- or di-) of glucuronidation in flavonoids with up to four hydroxyl groups. UV spectra of flavonoids and their respective mono-O-glucuronides were generated using UPLC with an online diode array detector. Analysis of the extent of shift in spectra of glucuronides in band I (300-385 nm) and band II (240-280 nm) regions as reflected by changes in lambdamax value was used to identify the position of glucuronidation. The data showed that glucuronidation of the 3- and 4'-hydroxyls resulted in band I lambdamax hypsochromic shifts (or blue shift) of 13-30 and 5-10 nm, respectively. Glucuronidation of the 5-hydroxyl group caused a band II lambdamax hypsochromic shift of 5-10 nm. In contrast, glucuronidation of the 7-hydroxyl group did not cause any lambdamax change in band I or II lambdamax, whereas glucuronidation of the 6-hydroxyl group did not cause predictable changes in lambdamax values. The paper demonstrated for the first time that a rapid and robust analysis method using lambdamax changes in online UV spectra can be used to pinpoint region-specific glucuronidation of flavones and flavonols with hydroxyl groups at the 4'-, 3-, 5-, and/or 7-position(s).

Flow injection analysis of ethyl xanthate by gas diffusion and UV detection as CS2 for process monitoring of sulfide ore flotation.

A sensitive and robust analytical method for spectrophotometric determination of ethyl xanthate, CH(3)CH(2)OCS(2)(-) at trace concentrations in pulp solutions from froth flotation process is proposed. The analytical method is based on the decomposition of ethyl xanthate, EtX(-), with 2.0 mol L(-1) HCl generating ethanol and carbon disulfide, CS(2). A gas diffusion cell assures that only the volatile compounds diffuse through a PTFE membrane towards an acceptor stream of deionized water, thus avoiding the interferences of non-volatile compounds and suspended particles. The CS(2) is selectively detected by UV absorbance at 206 nm (epsilon=65,000 L mol(-1) cm(-1)). The measured absorbance is directly proportional to EtX(-) concentration present in the sample solutions. The Beer's law is obeyed in a 1x10(-6) to 2x10(-4) mol L(-1) concentration range of ethyl xanthate in the pulp with an excellent correlation coefficient (r=0.999) and a detection limit of 3.1x10(-7) mol L(-1), corresponding to 38 microg L(-1). At flow rates of 200 microL min(-1) of the donor stream and 100 microL min(-1) of the acceptor channel a sampling rate of 15 injections per hour could be achieved with RSD<2.3% (n=10, 300 microL injections of 1x10(-5) mol L(-1) EtX(-)). Two practical applications demonstrate the versatility of the FIA method: (i) evaluation the free EtX(-) concentration during a laboratory study of the EtX(-) adsorption capacity on pulverized sulfide ore (pyrite) and (ii) monitoring of EtX(-) at different stages (from starting load to washing effluents) of a flotation pilot plant processing a Cu-Zn sulfide ore.

An instrument-based screening assay for DNA-targeted anticancer drugs using resonance light scattering.

DNA is a valid drug target for development of target-based therapeutics against cancer. Screening DNA-targeted anticancer drugs is a key process for the research and development of new anticancer drugs. The traditional anticancer drug screening methods, including animal experiments and cell-based screening assays, have unavoidable drawbacks. In this contribution, the new instrument-based screening assay for DNA-targeted anticancer drugs in vitro using resonance light scattering (RLS) technique was proposed. The experiments suggested that the increment of RLS intensity was directly proportional to the antitumor effect of anticancer drugs. Therefore, it was intuitive to obtain the sequence of the antitumor activity of four anticancer drugs without data processing as follows: mitoxantrone (MIT) > pirarubicin (PIR) > daunorubicin (DAU) > doxorubicin (DOX) by RLS screening spectra. Moreover, the apparent equilibrium constant (K) was 1.23 x 10(4), 2.22 x 10(4), 4.66 x 10(4) L/mol for DOX, DAU, and PIR, respectively. The inhibitory concentration 50 (IC50) was 0.148, 0.102, 0.025, 0.013 micromol/L for DOX, DAU, PIR, MIT, respectively. Therefore, the antitumor effect of four drugs was as follows: MIT > PIR > DAU > DOX, which was in good agreement with the result obtained from RLS screening assays. The mechanism between DNA and anthracycline drugs was investigated using UV-vis spectroscopy, fluorescence spectroscopy, and electrophoresis experiments. The proposed assay is a rapid, intuitive, and easy-to-conduct bioassay with good accuracy and reproducibility.

Assay conditions and validation of a new UV spectrophotometric method using microplates for the determination of polyphenol content.

A new spectrophotometric assay for the quantification of polyphenolic content has been validated. It is based on Prussian Blue method and adapted to microplate spectrophotometry. Prussian Blue reaction is critically dependent on reaction time, but microplate spectrophotometry permits exact measures of many samples at the same time. This new method is precise, reproducible, repeatable and exact.

IKNO, a user facility for coherent terahertz and UV synchrotron radiation.

IKNO (Innovation and KNOwledge) is a proposal for a multi-user facility based on an electron storage ring optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range, and of broadband incoherent synchrotron radiation ranging from the IR to the VUV. IKNO can be operated in an ultra-stable CSR mode with photon flux in the terahertz frequency region up to nine orders of magnitude higher than in existing third-generation light sources. Simultaneously to the CSR operation, broadband incoherent synchrotron radiation up to VUV frequencies is available at the beamline ports. The main characteristics of the IKNO storage and its performance in terms of CSR and incoherent synchrotron radiation are described in this paper. The proposed location for the infrastructure facility is Sardinia, Italy.

Capillary electrophoresis of some free fatty acids using partially aqueous electrolyte systems and indirect UV detection. Application to the analysis of oleic and linoleic acids in peanut breeding lines.

This study has shown for the first time the suitability of CE with a partially aqueous electrolyte system for the analysis of free fatty acids (FFAs) in small portions of single peanut seeds. The partially aqueous electrolyte system consisted of 40 mM Tris, 2.5 mM adenosine-5'-monophosphate (AMP) and 7 mM alpha-CD in (N-methylformamide) NMF/dioxane/water (5:3:2 by volume) mixture, pH 8-9. While AMP served as the background UV absorber for indirect UV detection of the FFAs, the alpha-CD functioned as the selectivity modulator by affecting the relative effective electrophoretic mobilities of the various FFAs due to their differential association with alpha-CD. This CE method allowed the screening of peanut seeds for their content of oleic and linoleic acids, which is essential in breeding of peanuts of high-oleic acid content. The extraction method of FFAs from peanut seeds is very reproducible with a high recovery approaching quantitative yield (approximately 97% recovery).

Photodegradation study of decabromodiphenyl ether by UV spectrophotometry and a hybrid hard- and soft-modelling approach.

This work presents an exploratory study of the photochemical degradation process of decabromodiphenyl ether (decaBDE) and gives an interpretation of the kinetic pathway, species and effects of the key factors involved in the degradation process. Use of lowly brominated diphenyl ethers (PBDE) has been banned by the EU and there seems to be evidence of the photolytic degradation of highly brominated PBDEs into lowly brominated congeners. Hence, the importance of knowing the photodegradation process of decaBDE. The photodegradation was investigated under UV light by UV-spectrophotometric monitoring. A novel hybrid data analysis approach, based on the combination of hard- and soft-spectrophotometric multivariate curve resolution, was applied to elucidate the mechanism of the degradation process, to resolve kinetic profiles and pure spectra of the photodegradation products and to evaluate the rate constants. The photodegradation process could be described with a kinetic model based on three consecutive first-order reactions and a decrease of the degradation process was observed as solvent polarity increased. Complementary identification of photodegradation products by gas chromatography coupled to mass spectrometry using negative chemical ionization (GC-NCI-MS) is attempted. This work presents a novel attempt of describing in a comprehensive way the photochemical degradation process of decaBDE, with all successive steps and related rate constants. This study proves also the potential of the proposed hybrid data analysis methodology as a general strategy to interpret the evolution of these photochemical reactions.