Assessing Microplastics and Nanoparticles in the Surface Seawater of Venice Lagoon-Part I: Methodology of Research.

Microplastics (MPs) and nanoplastics (NPs) both represent significant concerns in environmental sciences. This paper aims to develop a convenient and efficient methodology for the detection and measurement of MPs and nanoparticles from surface seawater and to apply it to the water samples collected from the UNESCO site of Venice and its lagoon, more precisely in the Venice-Lido Port Inlet, Grand Canal under Rialto Bridge, and Saint Marc basin. In this study, MPs were analyzed through optical microscopy for their relative abundance and characterized based on their color, shape, and size classes, while the concentration and the mean of nanoparticles were estimated via the Nanoparticle Tracking Analysis technique. Bulk seawater sampling, combined with filtration through a cascade of stainless-steel sieves and subsequent digestion, facilitates the detection of MPs of relatively small sizes (size classes distribution: >1 mm, 1000-250 µm, 250-125 µm, 125-90 µm, and 90-32 µm), similar to the size of MPs ingested by marine invertebrates and fishes. A protocol for minimizing interference from non-plastic nanoparticles through evaporation, digestion, and filtration processes was proposed to enrich the sample for NPs. The findings contribute to the understanding of the extent and characteristics of MPs and nanoparticle pollution in the Venice Lagoon seawater, highlighting the potential environmental risks associated with these pollutants and the need for coordinated approaches to mitigate them. This article is based on scientific research carried out within the framework of the H2020 In-No-Plastic-Innovative approaches towards prevention, removal and reuse of marine plastic litter project (G.A. ID no. 101000612).

First liquid chromatography-high resolution mass spectrometry method for the determination of cocaine on banknote dust.

PURPOSE: Prevalence measures of sociological interest concerning cocaine presence on banknotes are fraught with (i) the extreme variability of its concentration (seven orders of magnitude); (ii) the high number of banknotes needed for the statistical significance. Banknote dust from counting machines from a large and representative number of banknotes in circulation in a specific area represents the most eligible sample to ascertain cocaine circulation. No chromatographic method is available in this respect. This study aims at developing the first analytical methodology for the determination of cocaine in banknote dust samples. METHODS: This novel and straightforward approach consists of a simple methanol extraction followed by analytical determinations via ultra-high performance liquid chromatography coupled to Orbitrap high-resolution mass spectrometry. RESULTS: Satisfactory analytical performance was obtained with a coefficient of determination of 0.996; maximum within-run and between-run precisions were, respectively, 1.85% and 5.20%. Limits of detection and quantification were, respectively, 3 and 9 ng/mL with an overall process efficiency of 93.2%. The method developed was successfully applied to 9 banknote dust samples from local banknote counter machines. The found concentrations ranged from 2.18E + 02 to 2.31E + 03 µg of cocaine per gram of banknote dust and varied only one order of magnitude, much less than cocaine concentration on banknotes. CONCLUSIONS: To have an idea of cocaine circulation in a geographical area, the sampling of banknote dust, compared to banknotes, consists of tremendous advantages in terms of statistical significance, higher cocaine concentrations, and lower variability: this is crucial from the sociological point of view.

Recovery of gold from e-waste via food waste byproducts.

Global materials' and energy constraints and environmental issues call for a holistic approach to waste upcycling. We propose a chemically rational, cost-effective and environmentally friendly recovery of non-leaching gold from e-waste using aqueous chemistry with hydrogen peroxide, an environmentally benign oxidant, and lactic acid, a food chain byproduct. The oxidation of the base metals enables the release of gold in its metallic state in the form of flakes subsequently separated via filtration. Our main byproduct is a precursor of Cu2O, a relevant metal oxide for solar energy conversion applications. The recovered gold was characterized by scanning electron microscopy, energy dispersive spectroscopy and x-ray photoelectron spectroscopy to gain insight into the morphology of the flakes and their chemical composition. Furthermore, recovered gold was used to successfully fabricate the source and drain electrodes in organic field-effect transistors.

Scent of knowledge: The molecular fingerprint of volatiles in an emblematic historical library in Italy.

Heritage guidelines recognize odors as a value associated with a place. This study aims to clarify the connection between heritage and volatile organic compounds at the molecular level. At variance with previous studies, usually focused only on book-related compounds from accelerated degradation tests, the whole air of one of the most significant historical libraries in Italy was studied. A sampling of the volatiles off-gassing from the two most iconic rooms, respectively open and forbidden to visitors, was performed via a non-invasive, nondestructive green method, solid-phase-micro-extraction. The gas-chromatographic analyses resulted in the appraisal of olfactory contributions from books, storage environment, and, for the first time, anthropic activities and pollution.Concerning the paper decay process, for the very first time, the presence of 2-ethyl-1-hexanol in the chromatographic signature of the library air is rationalized according to the Guerbet reaction. The presence of all other compounds is explained by the paper decay process, anthropic sources, and pollution. Indoor air comprises analytes related to paper decay, identified by previous studies, and additional compounds never found before.Most volatile compounds are aliphatic and aromatic hydrocarbons, aldehydes, alcohols, terpenes, and terpenoids. Odor contributions from a selected number of analytes were pinpointed. Alkanes dominate the volatiles chromatographic signature, and impart a slight hydrocarbon smell. Aromatics supplement their characteristic aromatic odor. Aldehydes' very low odor threshold makes them strongly contribute to both fruity and fatty descriptors. Benzaldehyde, furfural, vanillin, and camphor add, respectively, an hint of almond, bread, vanilla, and camphor. Alcohols such as 2-ethyl hexanol have a floral scent. Wood-related terpenes and terpenoids contribute to the woody smell of the library.The digital molecular fingerprint of the "scent of knowledge" enables documentation, conservation, and future chemical reproduction of the historical library odor.

Analysis of volatiles organic compounds in Venice lagoon water reveals COVID 19 lockdown impact on microplastics and mass tourism related pollutants.

The Lagoon of Venice is a continuously evolving ecosystem that rapidly responds to anthropic stressors. The UNESCO World Heritage site "Venice and its Lagoon", is one of the top tourist destinations in the world. Mass tourism increases marine litter, water traffic emissions, solid waste, and sewage release. Plastic marine litter is not only a major aesthetic problem diminishing tourists experience of Venice, it also leaches contaminants into the seawater. Since there is a dearth in the literature regarding microplastic leachable compounds and overtourism related pollutants, the project studied the Head Space-Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) molecular fingerprint of volatile lagoon water pollutants, to gain insight into the extent of this phenomenon in August 2019. The chromatographic analyses enabled the identification of 40 analytes related to the presence of polymers in seawater, water traffic, and tourists habits. In Italy, on the 10th March 2020, the lockdown restrictions were enforced to control the spread of the SARS-CoV-2 infection; the ordinary urban water traffic around Venice came to a halt, and the ever-growing presence of tourists suddenly ceased. This situation provided a unique opportunity to analyze the environmental effects of restrictions on VOCs load in the Lagoon. 17 contaminants became not detectable after the lockdown period. The statistical analysis indicated that the amounts of many other contaminants significantly dropped. The presence of 9 analytes was not statistically influenced by the lockdown restrictions, probably because of their stronger persistence or continuous input in the environment from diverse sources. Results signify a sharp and encouraging pollution decrease at the molecular level, concomitant with the anthropogenic stress release, even if it is not possible to attribute quantitatively the VOCs load variations to specific sources (e.g., tourists' habits, urban water traffic, plastic pollution).

Novel microencapsulated yeast for the primary fermentation of green beer: kinetic behavior, volatiles and sensory profile.

The development of innovative and more cost-effective approaches of making beer throughout continuous fermentation process remains a challenging problem, which is worthy of serious exploration. The current work focuses on the application of a commercial brewing yeast (S. cerevisiae Nottingham Ale), entrapped into chitosan-calcium alginate double layer microcapsules, for the production of a Pale Ale beer. During the primary alcoholic fermentation, the consumption rate of fermentable brewing sugars and dissolved O2, estimated by the Gompertz equation, was halved in the beer obtained by encapsulated yeast in comparison with the free cell. The physical-chemical parameters of beer (i.e. pH, alcohol content, color and bitterness) were not remarkably affected by the different yeast-inoculating form. However, the volatile profiles identified by means of HS-SPME-GC-MS analysis, significantly differed in terms of terpenes, esters and alcohols content, thus proving that the yeast-inoculating form may typify the odor and flavor descriptors of the green beer.

A new and efficient lactic acid polymerization by multimetallic cerium complexes: a poly(lactic acid) suitable for biomedical applications.

Among many, poly(lactic acid) (PLA) has received significant consideration. The striking price and accessibility of l-lactic acid, as a naturally occurring organic acid, are important reasons for poly-(l)-lactic acid (PLLA) improvement. PLLA is a compostable and biocompatible/bioresorbable polymer used for disposable products, for biomedical applications, for packaging film, in the automotive industry, for electronic device components, and for many other applications. Formerly, titanium and other metals have been used in different orthopaedic screws and plates, but they are not degradable and therefore remain in the body. So, the development of innovative and eco compatible catalysts for polyester synthesis is of great interest. In this study, an innovative and eco sustainable catalyst was employed for PLLA synthesis. The combined CeCl3·7H2O-NaI system has been demonstrated to be a very valuable and nontoxic catalyst toward PLLA synthesis, and it represents a further example of how to exploit the antibacterial properties of cerium ions in biomaterials engineering. A novel synthesis of poly-(l)-lactic acid was developed in high yields up to 95% conversion and with a truly valuable molecular weight ranging from 9000 to 145 000 g mol-1, testing different synthetic routes.

On the antioxidant activity of eumelanin biopigments: a quantitative comparison between free radical scavenging and redox properties.

The antioxidant activity of eumelanin, a ubiquitous pigment in flora and fauna, constitutes one of its most fascinating physicochemical properties. To shed light on free radical scavenging vs redox facets of such activity, we applied hydrogen atom transfer- and electron transfer-based assays to pristine Sepia ink, eumelanin from Sepia ink, chemically controlled eumelanins and their precursor building blocks. Our work contributes to the rational use of the antioxidant properties of eumelanin for health, cosmetics and environmental applications.

Volatile and Sensory Profiles of Algerian Extra-Virgin Olive Oil from Souidi and Zeletni Cultivars.

In this study, the volatile and sensory profiles of monovarietal extra-virgin olive oil (EVOO) from two less widespread Algerian autochthonous cultivars (Souidi and Zeletni) were obtained using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry and a panel test, respectively. A total of 14 and 10 volatile compounds belonging to different chemical classes were identified and quantified in the Souidi and Zeletni EVOOs, respectively. Zeletni EVOO contains 2.07 times more (E)-2-hexenal than Souidi EVOO. In addition, the amounts of C6 compounds from LA and LnA, as well as the total amount of the compounds of the LOX pathway were higher in Zeletni than in the Souidi EVOO. Another important finding was the predominance of sesquiterpene ß-ocimene in the composition of the volatile fraction of Souidi EVOO. The sensory profiles of the EVOOs analyzed were characterized by fruity, bitter and pungent sensory positive attributes, perceived at medium intensity in both oils studied.

Unprecedented high percentage of food waste powder filler in poly lactic acid green composites: synthesis, characterization, and volatile profile.

The attractive qualities of plastics lead us, around the world, to an enormous need for plastic goods, which results in their unsustainable overconsumption. Bio-based products are the core concept of circular economy, yet this sector suffers from the high cost of their production. In practice, biopolymers, such as polylactic acid (PLA), are still limitedly used, due to their expensiveness and not outstanding technological properties. A circular and sustainable solution would be to use waste from the food industry as filler that contributes to reduce the cost of PLA-based materials, thereby encouraging their widespread use. At the same time, this would be a circular approach to wisely upgrade food waste and prevent pollution. Ceramic food waste powder fillers from egg shells and from mussel shells were compounded with PLA at 180 °C to obtain composites, which contain an unprecedented high amount of filler, equal to 140 over 100 parts of PLA. We analyzed volatile organic compounds emitted from PLA and, for the very first time, from its composites via headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The molecular fingerprint of the volatiles comprises only three aldehydes, a ketone, and two lactides. Volatiles typical of fossil plastics, that are causative factors of hormone disruption or reproductive dysfunction, are effectively missing. Scanning electron microscopy, used to examine the structure of the composite, indicates that both the egg shells and the mussel shells are suitable fillers, in that they form a sufficiently strong interface with the polymer.

An overview of experimental designs in HPLC method development and validation.

Chemometric approaches have been increasingly viewed as precious complements to high performance liquid chromatographic practices, since a large number of variables can be simultaneously controlled to achieve the desired separations. Moreover, their applications may efficiently identify and optimize the significant factors to accomplish competent results through limited experimental trials. The present manuscript discusses usefulness of various chemometric approaches in high and ultra performance liquid chromatography for (i) methods development from dissolution studies and sample preparation to detection, considering the progressive substitution of traditional detectors with tandem mass spectrometry instruments and the importance of stability indicating assays (ii) method validation through screening and optimization designs. Choice of appropriate types of experimental designs so as to either screen the most influential factors or optimize the selected factors' combination and the mathematical models in chemometry have been briefly recalled and the advantages of chemometric approaches have been emphasized. The evolution of the design of experiments to the Quality by Design paradigm for method development has been reviewed and the Six Sigma practice as a quality indicator in chromatography has been explained. Chemometric applications and various strategies in chromatographic separations have been described.

Microbiological characterisation and volatiles profile of model, ex-novo, and traditional Italian white wheat sourdoughs.

The interplay of sourdough microbiology and generated volatile compounds that define its sensory characteristics was studied. In order to detail the flavour generating potential of microorganisms, eight single-strain dough fermentations were studied, four of them never investigated before. Moreover, for the first time, both ex-novo and traditional wheat sourdoughs were investigated and compared to chemically acidified dough. HS-SPME-GC-MS was used to sample and analyse volatile compounds, some of which have never been detected before in sourdoughs. Alcohols, esters, carbonyl compounds, and acids mainly characterised the volatile profiles. Different sourdough microbiota resulted in different volatile profiles. PCA indicated that samples could be clustered according to their specific microbiota. Production of aroma compounds was strain-specific, confirming previous findings. This study can contribute to the management of desirable features and differentiate specialty products, as well as selecting new, suitable, sourdoughs after microbial screening.

Chromatography and the hundred year mystery of inorganic ions at aqueous interfaces: adsorption of inorganic ions at the Porous Graphitic Carbon Aqueous Interface follows the Hofmeister series.

Many physical phenomena are affected by the structure of water interfaces, yet it remains an active and controversial subject. A great deal of recent theoretical endeavour and computer simulations question the validity of the Onsager Samaras theory of the ion-free interface between an electrolyte solution and an hydrophobic surface. Experimental results play a crucial role in assessing the legitimacy of the theories. Experimental data are scarce, while simulation results suggest an increasing surface affinity of ions with increasing chaotropic character, in dramatic contradiction to the classical view. Chromatography is a powerful separative technique, but we originally used it as a tool to detect the adsorption of chloride electrolytes and sodium electrolytes, strongly expected to shun any dielectric boundary, onto an hydrophobic surface, and to rank ions according to their adsorbophilicities. Frontal analysis gave unequivocal experimental evidence to this unexpected phenomenon and it was used to quantify it. The infinite dilution equilibrium constants for adsorption of kosmotropes and chaotropes onto the interface were obtained and contrasted to the Jones-Dole B viscosity coefficients, that is a common quantifier of the Hofmeister effect. It is clear that (i) the more chaotropic the ion is, the more it contributes to the global adsorbophilicity of the electrolyte; (ii) the influence of the variable anion is more than twofold that of the variable cation, thereby confirming a robust observation in many other physical systems. Standard free energy of adsorption for each electrolyte was calculated and its reliability was commented upon. The central issue in this paper is the effective and ascertained adsorption of electrolytes onto an hydrophobic surface and the fact that the adsorbophilicity of an electrolyte may be inferred from its position in the Hofmeister series.

Volatile profiles of Italian monovarietal extra virgin olive oils via HS-SPME-GC-MS: newly identified compounds, flavors molecular markers, and terpenic profile.

This study aims to contribute to the knowledge of the commercial, sensory, and analytical characteristics of extra virgin olive oil (EVOO) from Italy (Marche region), renowned since ancient times. Headspace solid-phase micro-extraction (HS-SPME) was applied for the very first time to the sampling of volatile compounds of eleven typical Italian monocultivar EVOOs. Forty-eight compounds were characterised by GC-MS, some of them were only occasionally found in other EVOOs and some other were never detected before in any EVOO. Compounds belonging mainly to alcohols, esters, aldehydes, ketones and hydrocarbons chemical classes characterised the volatile profiles. The main volatile compounds detected in the EVOOs were the C6 compounds derived from polyunsaturated fatty acids, through the lipoxygenase pathway, in different proportion according to the specific cultivar. The results suggest that genetic factors strongly influence volatile formation and terpene hydrocarbons are claimed to be suitable markers of the geographic origin and genotype of the EVOO. Correlations among sensory attributes evaluated by a panel test and the presence of specific volatile compounds were highlighted for the very first time. The significance of the presence of some newly identified volatile compounds was discussed.

Retention Mechanism for Ion-Pair Chromatography with Chaotropic Reagents. From Ion-Pair Chromatography toward a Unified Salt Chromatography.

The breakthrough of chaotropic mobile phase modifiers in reversed-phase high-performance liquid chromatography (RP-HPLC) is due to their strong potential to provide adequate retention of ionic analytes without the blamed semipermanent modification of the chromatographic packing often connected to the use of classical ion-pair reagents. The lack of a physicochemical framework that is able to unify eclectic experimental evidence concerning the use of a wide gamut of ionic additives in RP-HPLC is the primary motive force for recent theoretical efforts to model their behavior. The time-honored solvophobic theory cannot properly explain salt effects. Its theoretical basis was recently questioned by breaking experimental evidence at variance with the textbook knowledge of ionic solutions interfaces; meanwhile, a recently proved extended thermodynamic approach to ion-pair chromatography (IPC) is challenged by the breakthrough of neoteric ionic additives whose behavior questions the rigidity of previous retention schemes and bridges salting chromatographic phenomena to IPC. Building on these research needs, the aims of this review are (1) to illustrate a comprehensive theory of analyte retention in the presence of any kind of electrolytes (hydrophobic ions, chaotropes, kosmotropes, ionic liquids [ILs]) to capture and rationalize the main salting effects and to support their strong practical impact for the separation of organic and inorganic ions, ionogenic, neutral, and zwitterionic analytes; (2) to explain why ion-specific salting chromatographic effects that represent a diachronic scientific consideration were not satisfactorily explained in the rubric of the solvophobic theory; and (3) to highlight the eligibility of chromatography as a basic technique that is able to clarify the currently hotly debated behavior of ions at water interfaces. The practical impact of chaotropic chromatography will also be detailed, and urgent research needs and suggestions will be illustrated.

The first quantitative rating system of the antioxidant capacity of beauty creams via the Briggs-Rauscher reaction: a crucial step towards evidence-based cosmetics.

Oxidative damage is the primary cause of skin aging. Skin care products are numerous and overwhelming, yet there is certain similarity among different formulations. Moisturizers are ubiquitous and the presence of particular added ingredients supports specific marketing claims. The antioxidant effects of botanical polyphenols possess tremendous marketing appeal, because oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the skin ability to neutralize them. The concept of evidence-based cosmetics lacks a widely accepted method to estimate the antioxidant capacity of the beauty cream. This was the motive force of the present study: for the first time we put forth a quantitative rating system of skin care products. The overall antioxidant power of 75 widely used and advertised beauty creams was comparatively measured via the oscillating Briggs-Rauscher (BR) reaction. Many dermocosmetic products confirmed their ability to ensure protection against free radicals, even if differences among various creams are striking and often not correlated with the their price. The method we developed is simple and cheap and it can allow dermatologists and consumers to compare and choose effectively; on the other hand, producers can used this method to select the most active antioxidant cosmetic agent to optimise the product performance.

Ion Pairing Chromatography.

The present state of ion-pair chromatography (IPC) is reviewed. Emphasis is placed on the theoretical modeling of the retention behavior of charged, zwitterionic, and neutral solutes, since the theory provides the generally good understanding of the factors affecting the separation. Although stoichiometric models were credited with the first easy-to-understand demonstration of the retention mechanism of IPC, they were thermodynamic models, consistent with fundamental physics, that extensively detailed the multiplicity of interactions involved in an IPC system. This review is also aimed at giving a broad outline of the progression of the application of this technique during the past decade. Many examples will be given of the analysis of a wide variety of materials, including chiral compounds. They assess the practical potential of this separation strategy. Detection and hyphenation are also described. The relation of IPC to other instrumental method of analysis, the importance of ion-pairing in different (non-extractive) analytical techniques, and not separative aims of IPC, that are topics for which there is a dearth in the literature, are critically reviewed.

Extended thermodynamic approach to ion interaction chromatography. Influence of the chain length of the solute ion: a chromatographic method for the determination of ion-pairing constants.

The influence of the chain length in Ion Interaction Chromatography (IIC), previously named Ion Pair Chromatography, was investigated. The system examined is a C18 stationary phase and a variable, salt-controlled, mixture of a phosphate buffer pH 2.1 in methanol containing tetrabutylammonium bromide as Ion Interaction Reagent. IIC proves to be a good alternative to the well established spectrophotometric and conductometric methods of obtaining thermodynamic ion-pairing constants. The latter increase with increasing analyte chain length and decrease with increasing methanol concentration in the eluent: both results support a physical chemical description of the hydrophobic ion-pairing process at variance with the classical, Bjerrum-type modelling of the purely electrostatic interaction between inorganic ions. The calculated deltaG(o) are reliable because they compare to non-chromatographic estimates of deltaG(o) for similar systems. The present extended thermodynamic approach is able to predict and explain why the purely electrostatic approach works better for lower analyte lipophilicity or higher organic modifier concentration.

Extended thermodynamic approach to ion interaction chromatography. A mono- and bivariate strategy to model the influence of ionic strength.

Recent breakthroughs in the theory of ion interaction chromatography (IIC) permit new analyses of the dependence of retention on different interdependent factors. The influence of the ionic strength / on the surface potential, the Donnan effect, and salting effects are taken into account to model the chromatographic behaviour of charged analytes in IIC. The most reliable experimental results found in the literature were used to test the retention equations that were developed following both a monovariate (/ changes as the concentration of H, ion interaction reagent, changes) and a bivariate (/ changes because of the simultaneous variation of H and of the background electrolyte concentrations) approach. The present extended thermodynamic model builds on the sound intuition of the electrostatic approach and proves to provide the most successful and exhaustive quantitative explanation of experimental evidence. It is also able to rationalise the less extensive agreement between the pure electrostatic approach predictions and experimental results. The adequacy of the model is supported by physically reliable estimates of the adjustable constant (ion-pair constants, deltaG degrees). Moreover statistical practice demonstrates that all the adjustable parameters (three at most) are statistically significant. A linear, zero crossing function with unit slope is obtained when k(pred) is plotted against k(exp). The mean percent error between k(pred) and k(exp) is 4.5% at most. In the absence of H the present retention equation reduces, as expected, to the relationship that describes the influence of / on the retention behaviour in reversed-phase liquid chromatography.

Melanins and melanosomes from llama (Lama glama L.).

Analysis of melanins and melanosomes in eight hair and skin samples taken of adult pigmented Argentine llamas (Lama glama L.) has been carried out. In each sample, eumelanins, pheomelanins and alkali-soluble melanins were identified. The total amount of melanins and the amount of eumelanins both decreased from black to reddish brown colour, while pheomelanins were found to be present in small quantities in each sample. Eumelanosomes were round and oval-shaped, displaying transverse striations clearly visible at low magnification. Dark brown samples revealed all four melanosomes stages. Stages I and II melanosomes appeared as large, asymmetrical vacuoles containing numerous microvesicles randomly scattered within an amorphous proteinaceous material (vesiculo-globular bodies). Stage III melanosomes had microgranular melanin deposits in the microvesicles and in the matrix. The fully melanized melanosomes (stage IV) were primarily round-shaped, showing an irregular outline and the electron-dense pigment was arranged to form large clusters. In light brown melanocytes, numerous melanosomes at different maturation stages could be found. Premelanosomes appeared ovoid, containing amorphous proteinaceous material and spotty and microgranular deposits. Mature melanosomes were fully melanized, homogeneously electron-dense, ovoid granules.