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Mecozzi M.,Laboratory of Chemometrics and Environmental Applications | Monakhova Y.,Chernyshevsky Saratov State University
International Journal of Environment and Health

In this paper we present a new ultraviolet (UV) spectroscopic method for the simultaneous and reagentless determination of bromide, bicarbonate, nitrate and sulphide ions in artificial seawater solutions, applicable to the monitoring of the marine environment. We collected the UV spectra of artificial seawater samples with salinity between 8 and 45 psu, having known concentrations of these anions. As their UV spectra result strongly overlapped, the anion concentrations were determined using the chemometric methods such as Principal Component Regression (PCR), Partial Least Squares Regression (PLS) and Multivariate Curve Resolution methods based on Independent Component Analysis (ICA) for the instrumental calibration. These chemometric tools, which are the novelty of the proposed method, allow to save time and cost of analysis. The analytical accuracy attainable by PCR, PLS and ICA based methods were compared and critically discussed, showing the lowest analytical accuracy of PCR with respect to PLS and ICA based methods. Copyright © 2013 Inderscience Enterprises Ltd. Source

Boccia P.,DIPIA Inc | Meconi C.,DIPIA Inc | Mecozzi M.,Laboratory of Chemometrics and Environmental Applications | Sturchio E.,DIPIA Inc
Journal of Toxicology and Environmental Health - Part A: Current Issues

Exposure to inorganic arsenic (iAs) through drinking water is a major public health concern affecting most countries. Epidemiologic studies showed a significant association between consumption of iAs through drinking water and different types of cancer. However, the exact mechanisms underlying As-induced cancer and other diseases are not yet well understood. The aim of this study is to determine the effects of exposure iAs (20 or 30 mg/L) on Vicia faba seedlings in terms of phytotoxicity, genotoxicity, and spectroscopy by investigation of molecular modifications using infrared (FTIR) and near infrared (FTNIR) spectroscopy. Further, the mitigation effects of a precursor of glutathione (GSH), N-acetylcysteine (NAC), were also assessed. Spectroscopic and genotoxicity analysis demonstrated that specific molecular changes were directly correlated with iAs exposure. Comet assay in Vicia faba showed significant effects at concentrations of 20 and 30 mg/L, depending on the structural changes involving nucleic acids as identified by FTIR and FTNIR spectroscopy. Results of phytotoxicity and micronuclei tests were significant only at higher iAs concentrations (30 mg/L), where an antioxidant effect of NAC was noted. The two spectroscopic techniques demonstrated molecular modifications predominantly associated with chemical interactions of iAs with biomolecules such as nucleic acids, carbohydrates, lipids, and proteins in Vicia faba. Our findings suggest that further studies are required to better understand the mechanisms underlying toxicity produced by different As chemical forms in vegetal and agricultural species. © 2013 Copyright Taylor & Francis Group, LLC. Source

Mecozzi M.,Laboratory of Chemometrics and Environmental Applications | Oteri F.,Laboratory of Chemometrics and Environmental Applications
Chemistry and Ecology

In this article, the effects of As alone and in combination with other pollutants on the flagellate Dunaliella tertiolecta were studied. Cultures of this microalga were subjected to growth-inhibition tests, according to the ISO protocol, using the same As concentration range for all tests; the results showed an obvious toxic effect for cultures exposed to As and As combined with Zn, whereas for cultures exposed to As combined with the nonionic surfactant Triton X-100 and ethylene glycol, hormetic effects were also observed. The same acetone extracts of cultures used in the growth-inhibition test were further examined using 3D visible (Vis) and attenuated total reflectance infrared (FTIR-ATR) spectroscopy. 3D Vis spectroscopy showed that As and As mixed with other pollutants did not have common dose-response effects. For example, most chlorophyll and carotenoid pigments were shown to be increased and/or decreased within the same growth-inhibition test. FTIR-ATR examination of the same solutions showed other differentiated effects of As alone and As combined with other pollutants, revealing quantitative modifications of phospholipid and fatty acid contents and structural modification of DNA and RNA. In addition, a multivariate elaboration of FITR spectra, performed by means of a multivariate statistical technique, principal component analysis (PCA), showed that the observed molecular modifications in D. tertiolecta can be clustered according to the different types of exposure to pollutants. These findings suggest that the molecular modifications caused by As exposure are also related to the type of toxic mechanism (i.e. synergic or additive) which results from the presence of other pollutants. © 2011 Taylor & Francis. Source

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