Search results for "Contamination"
showing 10 items of 916 documents
Possible interferences of mercury sulfur compounds with ethylated and methylated mercury species using HPLC-ICP-MS
2002
The HPLC-ICP-MS coupling technique is able to separate and detect methyl, ethyl and inorganic mercury isotopes specifically. An identification of ethyl mercury(+) is not possible when the widely used sodium tetraethylborate derivatisation method in combination with GC-AFS/AAS or ICP-MS techniques is performed because it contains ethyl groups.An unidentified compound with the same retention time as ethyl mercury was found in the HPLC chromatograms of industrial sewage samples and humic-rich soils of microcosm experiments after applying water vapour distillation. We also observed such unidentified peaks in samples of heavily contaminated sites in Eastern Germany, separated by HPLC fractionati…
A rapid and cost-efficient DMSO-based method for isolating DNA from cultured lichen photobionts
2010
We have developed a simple and fast procedure for the purification of PCR-quality DNA from cultured lichen photobionts. This new one-step method uses the solvent dimethyl sulfoxide (DMSO) combined with heat treatment to chemically breakdown algal and plant tissues. The DMSO-DNA extracts may be directly precipitated and purified by standard techniques in a total time of approximately 30 min. Compared to other DNA extraction protocols, the DMSO-based method suppresses the need for liquid nitrogen, any extraction buffer, grinding, phenol, and long incubation or centrifugation steps, thereby considerably reducing the possibility of contamination. In addition, minimal amounts of starting materia…
Complete decontamination and regeneration of DNA purification silica colum
2008
Silica columns are among the most used DNA purification systems, allowing a good yield of high-quality nucleic acids without organic extractions. Silica column regeneration protocols reported up to now to remove DNA traces are time-consuming, and their effectiveness on genomic DNA has not been demonstrated. Here we report a very rapid regeneration procedure that ensures no DNA carryover, independent of its size, without impairing column efficiency. The method takes advantage of the improved DNA removal by low concentrations of Triton X-100.
Analytical Methods for Pesticide Residue Determination in Bee Products
2002
Monitoring pesticide residues in honey, wax, and bees helps to assess the potential risk of these products to consumer health and gives information on the pesticide treatments that have been used on the field crops surrounding the hives. The present review seeks to discuss the basic principles and recent developments in pesticide analysis in bee products and their application in monitoring programs. Consideration is given to extraction, cleanup, chromatographic separation, and detection techniques.
Pressurized liquid extraction of organic contaminants in environmental and food samples
2015
Pressurized liquid extraction (PLE) is an automated technique that uses elevated temperature and pressure to achieve exhaustive extraction from solid matrices, so reducing solvent consumption and enhancing sample throughput when compared with traditional procedures. Hence, it can be considered an environment-friendly technique, generating small volumes of waste and reducing costs and time. This review focuses on application of this green technique to the analysis of organic contaminants in food and environmental matrices for monitoring purposes. We examine fundamentals and key aspects of the development of a PLE method, including pressurized hot-water extraction, together with some relevant…
Target analysis of primary aromatic amines combined with a comprehensive screening of migrating substances in kitchen utensils by liquid chromatograp…
2015
An analytical strategy including both the quantitative target analysis of 8 regulated primary aromatic amines (PAAs), as well as a comprehensive post-run target screening of 77 migrating substances, was developed for nylon utensils, using liquid chromatography-orbitrap-high resolution mass spectrometry (LC-HRMS) operating in full scan mode. The accurate mass data were acquired with a resolving power of 50,000 FWHM (scan speed, 2 Hz), and by alternating two acquisition events, ESI+ with and without fragmentation. The target method was validated after statistical optimization of the main ionization and fragmentation parameters. The quantitative method presented appropriate performance to be u…
Determination of stilbenes in Sicilian pistachio by high-performance liquid chromatographic diode array (HPLC-DAD/FLD) and evaluation of eventually m…
2008
In this work, we have investigated about the presence of several natural stilbenes in 12 samples of pistachios harvested from 10 different farms of Sicily (Bronte and Agrigento). At the same time, we have evaluated the relation between the stilbenes synthesis and the possible contamination of mycotoxin produced by Aspergillus flavus and Aspergillus parasiticus. We have found two types of stilbenes in the samples of pistachios examined: trans-resveratrol and trans-resveratrol-3-O-β-glucoside (trans-piceid). Their concentration ranged from 0.07 to 0.18 mg/kg (av. = 0.12 ± 0.03 mg/kg) for trans-resveratrol, from 6.20 to 8.15 mg/kg (av. = 6.97 ± 0.55 mg/kg) for trans-piceid and from 6.38 to 8.2…
Lead, cadmium and chromium content of edible vegetables grown in three different agricultural areas
1990
(1990). Lead, cadmium and chromium content of edible vegetables grown in three different agricultural areas. Food Additives & Contaminants: Vol. 7, No. sup1, pp. S22-S25.
Toxicity of binary mixtures of Cu, Cr and As to the earthworm Eisenia andrei
2020
AbstractChromated copper arsenate (CCA) mixtures were used in the past for wood preservation, leading to large scale soil contamination. This study aimed at contributing to the risk assessment of CCA-contaminated soils by assessing the toxicity of binary mixtures of copper, chromium and arsenic to the earthworm Eisenia andrei in OECD artificial soil. Mixture effects were related to reference models of Concentration Addition (CA) and Independent Action (IA) using the MIXTOX model, with effects being related to total and available (H2O and 0.01 M CaCl2 extractable) concentrations in the soil. Since only in mixtures with arsenic dose-related mortality occurred (LC50 92.5 mg/kg dry soil), it wa…
Premature aging in bone of fish from a highly polluted marine area
2015
Fish species have attracted considerable interest in studies assessing biological responses to environmental contaminants. In this study, the attention has been focussed on fishbone of selected fish species from a highly polluted marine area, Augusta Bay (Italy, Central Mediterranean) to evaluate if toxicant elements had an effect on the mineralogical structure of bones, although macroscopic deformations were not evident. In particular, an attempt was made to evaluate if bone mineral features, such as crystallinity, mineral maturity and carbonate/phosphate mineral content, determined by XR-Diffraction and FT-IR Spectroscopy, suffered negative effects due to trace element levels in fishbone,…