1,720,983 research outputs found
Electropolymerisation and electrochemical behavior of polypyrrole in deep eutectic solvents. An EQCM study
No full textErratum to "Electrochemical, spectroscopic and microscopic characterisation of novel poly(3,4-ethylenedioxythiopene)/gold nanoparticles composite materials" [Journal of Electroanalytical Chemistry 619-620 (2008) 75-82] (DOI:10.1016/j.jelechem.2008.03.009)
No full textPreliminary evaluation of the use of a disposable electrochemical sensor for selective identification of Δ9-tetrahydrocannabinol and cannabidiol by multivariate analysis
No full textThe widespread diffusion of products deriving from Cannabis sativa L. led to the necessity of rapid and reliable
methods for the identification of samples containing Δ9-tetrahydrocannabinol (THC), the psychoactive component
of the plant, which imparts mental distortions and hallucinations. Although some efficient electrochemical
sensors have been already proposed for such a purpose, they do not consider that the plant may also contain huge
amounts of cannabidiol (CBD), which possesses an electroactive moiety quite similar to that of THC. The definition
of both THC and CBD concentration is at the basis of discrimination between recreational-type and fibretype
cannabis samples; detection of these species is not only important in vegetable samples but also in relevant
commercial products and in biological fluids. We proposed here a screen-printed electrode coated with a layer of
carbon black for the rapid identification of samples containing THC irrespectively of the simultaneous presence
of CBD. The most performing carbon black typology used for such a purpose was chosen among various commercial
products tested on the basis of preliminary tests performed on 1,3-dihydroxybenzene, constituting the
redox active moiety of cannabinoids. The voltammetric responses collected in various solutions containing
different amount of THC and CBD were initially elaborated by Principal Component Analysis, assessing the
possibility of identifying samples with similar concentrations of THC irrespectively of the CBD concentration
values, and vice-versa. Afterwards a preliminary Partial Last Square regression was performed to evaluate the
possibility of a quantitative analysis of both THC and CBD. This approach suggests the possibility of using the
sensor proposed to screen samples containing THC even in the presence of high amounts of CBD
Development of an electrochemical sensor based on carbon black for the detection of cannabidiol in vegetable extracts
Full text linkA glassy carbon electrode chemically modified with a carbon black coating is proposed here for the rapid and portable determination of cannabidiol (CBD) in a commercial Cannabis seed oil and in fibre-type Cannabis sativa L. leaves. The mechanism of CBD oxidation was studied in relation to simpler phenyl derivatives bearing the same electroactive group, namely resorcinol and 2-methylresorcinol. These molecules also allowed us to determine the best conditions for the electrochemical detection of CBD, as to the pH value and to the best solvent mixture to use. Carbon black was chosen among nanostructured carbon-based materials owing to its outstanding features as an electrode modifier for analyte detection. The performance of the modified electrode was determined by flow injection analyses of standard solutions of CBD, obtaining a linear correlation between the oxidation current and the analyte concentration; the sensor response is characterised by suitable repeatability and reproducibility. The analysis of commercial products by the standard addition method allowed us to ascertain the accuracy of the sensor for the detection of CBD in real samples
An electrochemical approach for the prediction of Δ9-tetrahydrocannabinolic acid and total cannabinoid content in Cannabis sativa L
No full textTwo electrochemical sensors are proposed here for the first time for the fast screening of cannabinoids in Cannabis sativa L. plant material (inflorescences). The accurate control of cannabinoid content is important for discriminating between recreational, i.e. illegal, and fibre-type C. sativa samples, which differ mainly according to the amount of Δ9-tetrahydrocannabinol (Δ9-THC) and Δ9-tetrahydrocannabinolic acid (Δ9-THCA). Two screen printed electrodes obtained using different electrode materials were tested for the analysis of extracts from recreational and fibre-type C. sativa and their performance was compared with a consolidated method based on high-performance liquid chromatography (HPLC). The voltammetric responses recorded in the different samples reflected the compositional differences of the recreational and fibre-type extracts in accordance with the results of HPLC analyses. Moreover, the quantification of Δ9-THCA and the total cannabinoid content on the basis of the intensity of the peaks of the voltammograms was possible through a simple and fast electrochemical procedure
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Palladium(II) derivatives of alkylsulphanyl substituted thiophenes as precursors of inorganic polymers: spectroscopic, electrochemical investigations and X-ray crystal structure of trans-PdCl2[3-(butylsulfanyl)thiophene]2
No full textPalladium(II) complexes with two thiophene derivatives bearing alkylsulfanyl chains, i.e., 3-(n-butylsulfanyl)thiophene and 4,40-
bis(n-butylsulfanyl)-2,20-bithiophene, are synthesised and spectroscopically and electrochemically characterised. The molecular
structure of PdCl2[3-(n-butylsulfanyl)thiophene]2 was determined by X-ray analysis. The properties of the complexes have been compared
with those of PdCl2[3,30-bis(n-butylsulfanyl)-2,20-bithiophene] and of a conductive polymer partially coordinated with Pd(II),
previously synthesised by us. We found that Pd(II) ions can coordinate sulfanyl sulfur atoms both in cis and trans configuration,
leading to a reticulate material, where some kind of interchain bridging may be reasonably supposed to enhance the bulk
conductivity
Exchange Interactions Drive Supramolecular Chiral Induction in Polyaniline
No full textThe focus of this paper is on the intermolecular interaction active between polyaniline (PANI) and 10-camphorsulfonic acid (10CSA). Enantiopure 10CSA, present in the electropolymerization solution, promotes chiral induction in the supramolecular polyaniline polymer (cPANI). Tight integration of experimental data (circular dichroism, CD, near edge X-ray absorption spectra, NEXAFS, conductive probe atomic force microscopy, CP-AFM) and theoretical [density functional theory, (DFT)] results allows to unfold the nature of the electronic interaction between PANI and 10CSA and to shed light on the physical interactions inducing the chiral character to bulk pristine non-chiral PANI: eventually yielding cPANI. The electropolymerization follows a “wet chemistry” method: electrochemical polymerization of aniline in the co-presence in bulk solution of enantiopure 10-camphorsulfonic acid (10CSA). The latter is exploited as chirality inductor. The method of integration between experimental results with ab-initio theoretical calculations, strongly suggests that the chiral induction exerted by the CSA stems from exchange interaction between CSA and PANI
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