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Selenium nanoparticles (SeNPs) have attracted great attention in recent years due to their unique properties and potential bioactivities. While the production of SeNPs has been long reported, there is little news about the influence of reaction conditions and clean-up procedure on their physical properties (e.g., shape, size) as well as their antioxidant activity. This study takes up this issue. SeNPs were synthesized by two methods using cysteine and ascorbic acid as selenium reductants. The reactions were performed with and without the use of polyvinyl alcohol as a stabilizer. After the synthesis, SeNPs were cleaned using various procedures. The antioxidant properties of the obtained SeNPs were investigated using DPPH and hydroxyl radical scavenging assays. It was found that their antioxidant activity does not always depend only on the nanoparticles size but also on their homogeneity. Moreover, the size and morphology of selenium nanoparticles are controlled by the clean-up step. [ABSTRACT FROM AUTHOR]

Selenium nanoparticles (SeNPs) have attracted great attention in recent years due to their unique properties and potential bioactivities. While the production of SeNPs has been long reported, there is little news about the influence of reaction conditions and clean-up procedure on their physical properties (e.g., shape, size) as well as their antioxidant activity. This study takes up this issue. SeNPs were synthesized by two methods using cysteine and ascorbic acid as selenium reductants. The reactions were performed with and without the use of polyvinyl alcohol as a stabilizer. After the synthesis, SeNPs were cleaned using various procedures. The antioxidant properties of the obtained SeNPs were investigated using DPPH and hydroxyl radical scavenging assays. It was found that their antioxidant activity does not always depend only on the nanoparticles size but also on their homogeneity. Moreover, the size and morphology of selenium nanoparticles are controlled by the clean-up step.

Agricultural water is closely linked to surface and ground water as well as soil; hence, ensuring its safety is an important endeavor. We used the “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) method to analyze multi-residue pesticides in agricultural water by using a combined-sorbent-based clean-up procedure. Among the various sorbents examined, clean-up using ENVI-Carb combined with a primary secondary amine sorbent delivered the highest recovery of multi-residue pesticides (>93.9%). While the developed method showed satisfactory linearity (R2 > 0.9991), precision, and specificity, recovery was low for pyrazolate (29.1%) and thidiazuron (59.2%). The limits of detection and quantification for the 55 pesticides targeted in this study were in 0.02–3.0 μg L−1 and 0.1–9.9 μg L−1, respectively. The developed method was used to identify and quantify multi-residue pesticides during sample analysis. The results suggest that the QuEChERS method employing a combination of ENVI-Carb and another sorbent can be applied for the effective analysis of multi-residue pesticides in agricultural water.

The article offers information on topics related to biological warfare. Topics mentioned include the threat of biological warfare and terrorism to society, the need to prevent biological weapons and warfare, and the role of the U.S. Environmental Protection Agency (EPA) in biological decontamination. Also mentioned are the development of microbial risk assessment (MRA) methodology by EPA in biological decontamination and the importance of the environmental cleanup role by EPA.

Highlights: [•] This review discusses extraction and clean-up methods used to monitor OCP in milk. [•] Conventional extraction methods are still the most used, despite its disadvantages. [•] New extraction methods have not been evaluated in detail for OCP analysis in milk. [•] More research is needed to obtain the ideal method for OCPs determination in milk. [Copyright &y& Elsevier]

Abstract: This article critically reviews the principles and the applications of synchronous spectrofluorimetry as an analytical tool, focusing mainly on the recent innovative advances in this field of research. Unlike other reviews, this article includes not only detection using synchronous fluorescence (SF) but also the entire analytical procedure involving it (i.e. extraction and previous clean-up procedures if needed, derivatization process, use of micellar media, and derivative technique or multivariate-calibration methods applied to treatment of SF signals). The article is in two parts, the first devoted to general features of the synchronous procedure and the second one to analytical applications of different modes of SF – constant-wavelength, constant-energy and variable-angle (in wavelength and energy domains and in linear and non-linear variants). We discuss practical considerations, and evaluate the possibilities and the limitations of each synchronous modality, intending to show the serious drawbacks of applying synchronous spectrofluorimetry to very complex mixtures, avoiding previous clean-up procedures and constructing inaccurate calibration sets. Finally, this review compares SF and other analytical methodologies. It includes more than 200 references to the last advances in this technique, and several tables and figures, to facilitate the readers’ rapid comprehension of the relevant aspects in the field of SF. [ABSTRACT FROM AUTHOR]

Abstract: The EU maximum limit of 10μgkg−1 of OTA for dried vine fruits has been established since 2002 (European Commission, 2005). The presented work explore the capability of using Fourier infrared spectroscopy attenuated total reflection (FTIR-ATR) for the detection of ochratoxin A (OTA) in dried vine fruits in a range of concentration between 2 and 50μgkg−1 OTA. The method developed included a sample pretreatment using a C18 cartridge which was efficient for the isolation of the mycotoxin. The PLS1 analysis of the spectrum of sultanas spiked with different OTA concentrations showed a good correlation between the spectral data and reference concentration for OTA (R 2 =0.85). [Copyright &y& Elsevier]

The aim of this study was to optimise and validate a method for analysing eleven phenolic compounds belonging to different subclasses (phenolic acids, stilbenes and flavonoids) in grape skins. The method proposed includes a solid phase extraction step of purification and concentration prior to HPLC analysis. Under the optimised conditions, the total HPLC run time was reduced from 150 to 75 mm. The method showed high precision (3-12%). There was a high linearity of response for all the compounds analysed (r²⩾0.998) over the normal range for grape. The method was used to analyse the phenolics in Aglianico and Uva di Troia grape skins. Greater amounts of all the flavonoids and stilbenes were found in the Uva di Troia grape skins with respect to the Aglianico ones. [ABSTRACT FROM AUTHOR]