14 research outputs found
The NORMAN Association and the European Partnership for Chemicals Risk Assessment (PARC): let’s cooperate! [Commentary]
The Partnership for Chemicals Risk Assessment (PARC) is currently under development as a joint research and innovation programme to strengthen the scientific basis for chemical risk assessment in the EU. The plan is to bring chemical risk assessors and managers together with scientists to accelerate method development and the production of necessary data and knowledge, and to facilitate the transition to next-generation evidence-based risk assessment, a non-toxic environment and the European Green Deal. The NORMAN Network is an independent, well-established and competent network of more than 80 organisations in the field of emerging substances and has enormous potential to contribute to the implementation of the PARC partnership. NORMAN stands ready to provide expert advice to PARC, drawing on its long experience in the development, harmonisation and testing of advanced tools in relation to chemicals of emerging concern and in support of a European Early Warning System to unravel the risks of contaminants of emerging concern (CECs) and close the gap between research and innovation and regulatory processes. In this commentary we highlight the tools developed by NORMAN that we consider most relevant to supporting the PARC initiative: (i) joint data space and cutting-edge research tools for risk assessment of contaminants of emerging concern; (ii) collaborative European framework to improve data quality and comparability; (iii) advanced data analysis tools for a European early warning system and (iv) support to national and European chemical risk assessment thanks to harnessing, combining and sharing evidence and expertise on CECs. By combining the extensive knowledge and experience of the NORMAN network with the financial and policy-related strengths of the PARC initiative, a large step towards the goal of a non-toxic environment can be taken
The oxidation of luteolin, the natural flavonoid dye
The oxidation of natural flavonoid luteolin in aqueous solution is studied by electrochemical methods,
electron paramagnetic resonance (EPR), spectroelectrochemistry and separation techniques HPLC-DAD
and HPLC–MS/MS. The number of electrons involved in the oxidation of luteolin depends on the presence
of its dissociation forms in solution. The study explains the differences in the number of electrons
presented in the literature. The overall one electron oxidation mechanism of luteolin in alkaline solution
is explained by the comproportionation reaction of resulting quinone, despite the fact that quinone
is formed by two electron oxidation. Then a hydroxylation takes place. The EPR spectroelectrochemical
study of the semiquinone radical anion formation as well as of the reaction steps following the
electron transfer during the oxidation is presented. The novelty of this contribution consists in the additional
temperature controlled semi-quantitative in situ EPR spectroelectrochemical experiment of the
flavonoid oxidation. The data acquired by temperature controlled in situ EPR spectroelectrochemistry
supports the comproportionation/disproportionation equilibria as well as the oxidative decomposition
of luteolin and shows that the formation of a pi-dimer is less probable. The oxidation products hydroxyluteolin
and 3,5-dihydroxy-2-(2-oxoacetyl)phenyl-3,4-dihydroxybenzoate are not stable under ambient
conditions and decompose to low molecular hydroxycompounds such as 3,4-dihydroxybenzoic acid and
2,5,7-trihydroxy-4H-1-benzopyran-4-one
Sulfur- and Nitrogen-Containing Porous Donor-Acceptor Polymers as Real-Time Optical and Chemical Sensors
Fully aromatic, organic polymers have the advantage
of being composed from light, abundant elements, and are hailed as candidates
in electronic and optical devices “beyond silicon”, yet, applications that make
use of their π-conjugated backbone and optical bandgap are lacking outside of
heterogeneous catalysis. Herein, we use a series of sulfur- and
nitrogen-containing porous polymers (SNPs) as real-time optical and electronic
sensors reversibly triggered and re-set by acid and ammonia vapors. Our SNPs
incorporate donor-acceptor and donor-donor motifs in extended networks and
enable us to study the changes in bulk conductivity, optical bandgap, and
fluorescence life-times as a function of π-electron de-/localization in the pristine
and protonated states. Interestingly, we find that protonated donor-acceptor
polymers show a decrease of the optical bandgap by 0.42 eV to 0.76 eV and
longer fluorescence life-times. In contrast, protonation of a donor-donor polymer
does not affect its bandgap; however, it leads to an increase of electrical conductivity
by up to 25-fold and shorter fluorescence life-times. The design strategies
highlighted in this study open new avenues towards useful chemical switches and
sensors based on modular purely organic materials
The NORMAN Association and the European Partnership for Chemicals Risk Assessment (PARC): let’s cooperate!
The Partnership for Chemicals Risk Assessment (PARC) is currently under development as a joint research and innovation programme to strengthen the scientific basis for chemical risk assessment in the EU. The plan is to bring chemical risk assessors and managers together with scientists to accelerate method development and the production of necessary data and knowledge, and to facilitate the transition to next-generation evidence-based risk assessment, a non-toxic environment and the European Green Deal. The NORMAN Network is an independent, well-established and competent network of more than 80 organisations in the field of emerging substances and has enormous potential to contribute to the implementation of the PARC partnership. NORMAN stands ready to provide expert advice to PARC, drawing on its long experience in the development, harmonisation and testing of advanced tools in relation to chemicals of emerging concern and in support of a European Early Warning System to unravel the risks of contaminants of emerging concern (CECs) and close the gap between research and innovation and regulatory processes. In this commentary we highlight the tools developed by NORMAN that we consider most relevant to supporting the PARC initiative: (i) joint data space and cutting-edge research tools for risk assessment of contaminants of emerging concern; (ii) collaborative European framework to improve data quality and comparability; (iii) advanced data analysis tools for a European early warning system and (iv) support to national and European chemical risk assessment thanks to harnessing, combining and sharing evidence and expertise on CECs. By combining the extensive knowledge and experience of the NORMAN network with the financial and policy-related strengths of the PARC initiative, a large step towards the goal of a non-toxic environment can be taken. © 2020, The Author(s)