Search results for "Extraction"
showing 10 items of 2072 documents
Rapid PCR-based test for identifying Candida albicans by using primers derived from the pH-regulated KER1 gene.
2006
A PCR-based method in combination with a simple, reliable and inexpensive DNA extraction procedure for rapid detection of Candida albicans clinical isolates is described here. The extraction protocol is based on a combination of chemical (NaOH and detergents) and physical (boiling) treatments, thus avoiding many of the problems inherent in the currently available DNA extraction protocols (basically the use of expensive and/or toxic chemical reagents), and may be useful for daily clinical routine. The PCR-based system described here uses a single pair of primers (SC1F and SC1R) deduced from the C. albicans-specific KER1 gene sequence. These primers amplify a 670-bp fragment of the KER1 gene.…
Evolution of emerging Fusarium mycotoxins contents throughout the shelf-life period of food
2014
which is cooked by steaming. It has been historically eaten in North African countries but nowadays its consumption is widely extended all around the world. As a cereal-based food, semolina is highly susceptible to contamination by mycotoxin-producing fungi. The presented procedure involves a modified QuEChERSbased extraction of 24 mycotoxins (15-ADON, 3-ADON, AFLAB1, AFLAB2, AFLAG1, AFLAG2, BEA, DON, DAS, ENA, ENA1, ENB, ENB1, FB1, FB2, FB3, FUSX, HT-2, NEO, NIV, OTA, STG, T2, ZEA) produced by Aspergillus, Penicillum and Fusarium fungi. The validation was performed by analyzing recovery samples at three different spiked concentrations with four replicates (n=4) at each concentration. Recov…
Isolation, purification, LC–MS/MS characterization and reactive oxygen species induced by fumonisin B1 in VERO cells
2010
Fumonisins are mycotoxins produced by Fusarium verticillioides that commonly contaminate maize and maize products. The present work shows the results of a comparative study of three different fermentation's techniques (solid and liquid medium of corn and a solid agarized medium) for the production of fumonisins B-1, B-2 and B-3 with strains of F. verticillioides. The solid medium of corn was the most effective in the production of fumonisins, being Fumonisin B-1 the one produced with higher concentration, so the extract obtained by solid fermentation process was used for FB1 purification. Fumonisins characterization and quantification were performed with reversed-phase high-performance liqu…
Identification and Quantification of Enniatins and Beauvericin in Animal Feeds and Their Ingredients by LC-QTRAP/MS/MS
2019
Emerging fusariotoxins, mainly enniatins (ENNs) and beauvericin (BEA), are secondary toxic metabolites produced by Fusarium spp. and are widely distributed contaminants of cereals and by-products. Mycotoxin contamination in these products supposes an important risk to feed supply security in the feed industry due to the common use of cereals in feed formulations. Hence, continuous monitoring of both raw materials and feed mixtures is highly recommended as stated by sanitary authorities. Therefore, an analytical procedure based on liquid chromatography tandem mass spectrometry and an acetonitrile-based extraction followed by a d-SPE (QuEChERS) step for the simultaneous determination of emerg…
Comparison of extraction and clean-up procedures for analysis of zearalenone in corn, rice and wheat grains by high-performance liquid chromatography…
2002
The aim of this work was the optimization of some procedures usually used in the analysis of zearalenone (ZEA) in corn and other cereals by high-performance liquid chromatography (HPLC) with photodiode array and/or fluorescence detection. The comparison of five extraction solvents is presented. Three solid-phase extraction cartridges (C-18, silica, Florisil) and immuno-affinity columns were also compared to obtain the best recovery of the mycotoxin with the minimal presence of co-extractives in the chromatograms. Mixtures of methanol-1% aqueous NaCl (80.20 or 60:40 v/v) were the best extraction solvents. Florisil provided higher recovery of ZEA than C-18, and silica proved unsuitable. The i…
Liquid chromatographic determination of toxigenic secondary metabolites produced by Fusarium strains.
2002
Various liquid chromatographic methods used in the analysis of mycotoxins (zearalenone, trichothecenes and fumonisins) produced by Fusarium species were compared in this work. The results demonstrate the suitability of modern clean-up procedures employing multifunctional MycoSep and immunoaffinity columns although these methods are more expensive than conventional methodologies for clean-up. HPLC with both fluorescence and photodiode array detection is a suitable technique for the analysis of toxic secondary metabolites produced by Fusarium species; different derivatisation strategies have been studied to improve the sensitivity of the technique because of the low concentration of these met…
Simultaneous determination of Fusarium mycotoxins in wheat grain from Morocco by liquid chromatography coupled to triple quadrupole mass spectrometry
2014
Abstract In the present study, eighteen (18) mycotoxin produced by the genus Fusarium (fumonisins (FB1, FB2 and FB3), type-B trichothecenes (NIV, DON, FUS-X, 3Ac-DON and 15Ac-DON), type-A trichothecenes (NEO, DAS, T2 and HT2), zearalenone (ZEA), beauvericin (BEA), and enniatins (ENA, ENA1, ENB and ENB1)) were monitored in different samples of wheat grain commercialized in Morocco. A liquid chromatography coupled to triple quadrupole mass spectrometry method previous matrix solid phase dispersion extraction was used for sample analysis. A total of eighty (80) samples of durum wheat were collected in different local markets from several areas in Morocco. Analytical results showed that 54 out …
Impact of gadolinium on the structure and magnetic properties of nanocrystalline powders of iron oxides produced by the extraction-pyrolytic method
2020
The work has been done in frame of the TransFerr project. It has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 778070. This research was also supported by Latvian Research Council project lzp-2018/1-0214. A.I.P. appreciates support from the Estonian Research Council grant (PUT PRG619).
Analytical Methods for the Determination of Perfume-related Substances.
2014
Las fragancias son productos químicos que desprenden un olor agradable y que se utilizan en multitud de productos de consumo a los que confieren su característico aroma. Así, se pueden encontrar en productos cosméticos de todo tipo (tales como perfumes, champús, desodorantes o jabones) y también en productos para el hogar (como detergentes, ambientadores o velas). El uso de productos cosméticos se ha incrementado progresivamente con el paso del tiempo, considerándose un indicador del progreso y bienestar de un país. El reciente Reglamento Europeo sobre productos cosméticos armoniza íntegramente las normas comunitarias a fin de lograr la libre circulación de los productos y garantizar un ele…
Evaluation of sampling adsorbents and validation of a LC-HRMS method for determination of 28 airborne pesticides
2018
A new strategy for sampling, using a low-volume sampler, and determination of airborne pesticides by liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) has been developed. The trapping efficiency of three adsorbents (sandwich PUF-XAD2-PUF; XAD-2 and XAD-4) was tested for 33 currently used pesticides and the first adsorbent (PUF-XAD2-PUF) was selected because it presented the highest retention capacity without breakthrough. Selected PUF-XAD2-PUF had the following design: 5 g of Amberlite XAD-2 sandwiched between two cylinders of PUF (6.87 cm(3), height: 1.4 cm, diameter: 2.5 cm). A validation of the analytical methodology that includes microwave extraction with e…