Fast Detection of Different Water Contaminants by Raman Spectroscopy and Surface-Enhanced Raman Spectroscopy

Fast monitoring of water quality is a fundamental part of environmental management and protection, in particular, the possibility of qualitatively and quantitatively determining its contamination at levels that are dangerous for human health, fauna and flora. Among the techniques currently available, Raman spectroscopy and its variant, Surface-Enhanced Raman Spectroscopy (SERS), have several advantages, including no need for sample preparation, quick and easy operation and the ability to operate on the field. This article describes the application of the Raman and SERS technique to liquid samples contaminated with different classes of substances, including nitrates, phosphates, pesticides and their metabolites. The technique was also used for the detection of the air pollutant polycyclic aromatic hydrocarbons and, in particular, benzo(a)pyrene, considered as a reference for the carcinogenicity of the whole class of these compounds. To pre-concentrate the analytes, we applied a methodology based on the well-known coffee-ring effect, which ensures preconcentration of the analytes without any pretreatment of the sample, providing a versatile approach for fast and in-situ detection of water pollutants. The obtained results allowed us to reveal these analytes at low concentrations, close to or lower than their regulatory limits

Photodegradation of azodyes: Comparison of different catalytic systems and control of the effective mineralisation

Three different azodyes were used as target molecules to test the efficiency of the photodegradation process catalysed by titanium dioxide under UV irradiation. A comparison of different catalytic systems was performed using the catalyst both free in solution (system I) and immobilised in a polymeric membrane (system II). Iron oxalate and a conducting polymer (polyaniline, PA) were added to the I and II systems respectively to check an eventual synergetic effect. The research evolved through three different steps involving each one the use of a different analytical method. Shortly, the UV spectrophotometry were preliminarily used to monitor the bleaching process and allowed to choose the best catalytic system, HPLC and GC/MS were used to monitor the appearance and disappearance of the photodegradation intermediates and, lastly, the effective mineralisation was tested by an indirect ICP (Inductively Coupled Plasma) determination of the produced carbon dioxide

Photoacoustic Laser System for Food Fraud Detection

Economically motivated adulterations of food, in general, and spices, in particular, are an emerging threat to world health. Reliable techniques for the rapid screening of counterfeited ingredients in the supply chain need further development. Building on the experience gained with CO2 lasers, the Diagnostic and Metrology Laboratory of ENEA realized a compact and user-friendly photoacoustic laser system for food fraud detection, based on a quantum cascade laser. The sensor has been challenged with saffron adulteration. Multivariate data analysis tools indicated that the photoacoustic laser system was able to detect adulterants at mass ratios of 2% in less than two minutes

Assessment of radioactivity in commercially available honey in Italy

Activity concentration of natural radionuclides and 137Cs were estimated in 28 honeys purchased from large supermarket chains in Italy. Uranium, polonium and thorium were measured by alpha spectrometry, 40K and 137Cs by gamma spectrometry and 226Ra by liquid scintillation. The concentrations were 50.6±46.3, 0.023±0.010, 0.019±0.017, 0.27±0.40 Bqkg-1 for 40K, 238U, 234U and 210Po respectively. 235U, 228Th, 232Th were consistently <0.007 Bqkg-1 and 226Ra <0.200 Bqkg-1. 137Cs was <2.1 Bqkg-1 in 93% of the samples. The activity of radiocesium was found to be above the minimum detectable level in only two samples and did not exceed the highest permitted level for food contributing to the overall radioactivity only slightly. The effective doses attributable to 210Po accounts for 0.0026-5.31% of global human exposure to natural radiation. The honeys that were tested were found to be of good quality with regard to the parameters under study, confirming the general image of honey as a genuine healthy product

Assessment of radioactivity in Italian baby food

A set of measurements have been conducted to determine the activity-level of natural and artificial radionuclides in some baby foods commercialized in Italy. The measurements have been carried out using liquid scintillation, gamma, alpha and mass spectrometry. The activity concentrations ranged from 0.005 to 0.238, from 0.0082 to 1.65 and from 0.0003 to 0.015from <13.6 to 233.3 Bq kg-1 for 210Po, 238U, 232Th and 40K respectively, whereas they are below the detection limit for 137Cs and 226Ra. The annual effective dose due to intake of 210Po, 238U, 232Th and 40K ranged from 280 and 800 Svy-1 for infant 1 year old. These values lie well within the typical worldwide range of dose due to the ingestion of all natural radiation reported by UNSCEAR and they are below the internationally recommended level. This indicates that the baby food available in Italy would not pose any significant radiological impact to infant

Oregano herb adulteration detection through rapid spectroscopic approaches: Fourier transform-near infrared and laser photoacoustic spectroscopy facilities

Oregano is a culinary herb known and used worldwide, whose demand and cost encourage illegal activities in terms of fraud, especially adulteration. The scope of this study is to provide a rapid, cost-effective and easy-to-use approach to detect the adulteration of oregano with a common matrix, the olive leaves. Two analytical solutions were considered, Fourier transform near infrared (FT-NIR), using two different instruments, and laser photoacoustic spectroscopy (LPAS). Different raw data preprocessing procedures were applied, Principal Component Analysis (PCA) was used for preliminary data visualisation, while Partial Least Squares Regression (PLS-R) and Discriminant Analysis (PLS-DA) allowed the authors to classify samples with different adulteration percentages. FT-NIR performed better than LPAS, perhaps also because the photoacoustic system is still an experimental prototype. For example, the coefficient of determination R2 between actual and predicted adulterant concentrations was in the range 0.93–1.00 for FT-NIR and in the range 0.86–0.96 for LPAS. Nevertheless, this allowed the use of a low level data fusion approach to increase the consistency of the statistical model. The fusion between raw data from the LPAS prototype and one of the FT-NIR instruments gave optimal results, confirming the potential of these analytical solutions for the identification of oregano adulterants. The approaches used in the present work could be applied to the identification of other adulterants in herbs and spices by food companies for quality control measurements, possibly for on line and in field analysis

The Streptococcus agalactiae cell wall-anchored protein PbsP mediates adhesion to and invasion of epithelial cells by exploiting the host vitronectin/αv integrin axis

International audienceBinding of microbial pathogens to host vitronectin (Vtn) is a common theme in the pathogenesis of invasive infections. In this study, we characterized the role of Vtn in the invasion of mucosal epithelial cells by Streptococcus agalactiae (i.e. group B streptococcus or GBS), a frequent human pathogen. Moreover, we identified PbsP, a previously described plasminogen-binding protein of GBS, as a dual adhesin that can also interact with human Vtn through its streptococcal surface repeat (SSURE) domains. Deletion of the pbsP gene decreases both bacterial adhesion to Vtn-coated inert surfaces and the ability of GBS to interact with epithelial cells. Bacterial adherence to and invasion of epithelial cells were either inhibited or enhanced by cell pretreatment with, respectively, anti-Vtn antibodies or Vtn, confirming the role of Vtn as a GBS ligand on host cells. Finally, antibodies directed against the integrin αv subunit inhibited Vtn-dependent cell invasion by GBS. Collectively, these results indicate that Vtn acts as a bridge between the SSURE domains of PbsP on the GBS surface and host integrins to promote bacterial invasion of epithelial cells. Therefore, inhibition of interactions between PbsP and extracellular matrix components could represent a viable strategy to prevent colonization and invasive disease by GBS

Morphological parameters of lobular in situ neoplasia in stereotactic11-gauge vacuum-assisted needle core biopsy do not predict the presence of malignancy on subsequent surgical excision

Aims: The management of lobular in situ neoplasia (LN) when diagnosed on core biopsy remains a controversial issue. The present study aimed to investigate the association between morphological parameters of LN on vacuum-assisted needle core biopsy (VANCB) and the presence of malignancy (ductal carcinoma in situ, pleomorphic lobular carcinoma in situ, or invasive carcinoma) at surgical excision (SE). Methods and results: The study included 14 pathology departments in Italy. Available slides from 859 cases of VANCB reporting an original diagnosis of flat epithelial atypia, atypical ductal hyperplasia or LN, all with subsequent surgical excision, were reviewed. Overall, 286 cases of LN, pure or associated with other lesions, were identified, and a malignant outcome was reported at excision for 51 cases (17.8%). Among the 149 cases of pure LN, an increased risk of malignancy emerged in women in mammographic categories R4-R5 as compared with those in categories R2-R3 (OR 2.46; P = 0.048). In the series, a statistically significant decreased malignancy risk emerged among cases without determinant microcalcifications (P = 0.04). Conclusions: Our results suggest that the diagnosis of pure LN on VANCB warrants follow-up excision, because clinicopathological parameters do not allow the prediction of which cases will present carcinoma at surgical excision. © 2013 John Wiley and Sons Ltd

GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK: SUMMARY OF A RECENT EXERCISE

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop theircollective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency. A recent exercise was conductedto test the participating laboratories for their capabilities in screening and in vitro assay of biological samples, performinginternal dose assessment and providing advice on medical intervention, if necessary, using a urine sample spiked with a singleradionuclide, 241Am. The laboratories were required to submit their reports according to the exercise schedule and using pre-formattedtemplates. Generally, the participating laboratories were found to be capable with respect to rapidly screening samplesfor radionuclide contamination, measuring the radionuclide in the samples, assessing the intake and radiation dose, and providingadvice on medical intervention. However, gaps in bioassay measurement and dose assessment have been identified. Thenetwork may take steps to ensure that procedures and practices within this network be harmonised and a follow-up exercise beorganised on a larger scale, with potential participation of laboratories from the networks coordinated by the InternationalAtomic Energy Agency and theWorld Health Organization