0000000000077489
AUTHOR
Liliana J.g. Silva
Occurrence of fumonisins B1 and B2 in broa, typical Portuguese maize bread
Fumonisin B1 (FB1) and fumonisin B2 (FB2) are mycotoxins mainly produced by Fusarium verticillioides, and Fusarium proliferatum, fungi species most commonly isolated from maize. The natural occurrence of FB1 and FB2 in broa, typical Portuguese maize bread, was evaluated in 30 samples. Twenty five were found positive with levels ranging from 142 to 550 [mu]g kg- 1. The limit established by the European regulations was exceeded by 27% of the samples. The tolerable daily intake for fumonisin B1, and B2, alone or in combination, for all of the analysed samples, was lower than 2 [mu]g kg- 1 body weight per day established by the European Commission. http://www.sciencedirect.com/science/article/B…
Comparison of three solid-phase extraction processes in quantification of ciprofloxacin and enrofloxacin in pork meat
Due to strong implications for food safety, control of fluoroquinolones residues in swine meat should be undertaken to verify compliance of the contamination levels with the maximum residue limits recently updated by Commission Regulation (EU) No. 37/2010 of 22 December 2009. Solid-phase extraction is widely used in antibiotic analysis in food of animal origin. In this study, the results of a comparative study using different types of solid-phase extraction columns, HLB, MCX, and MAX, for ciprofloxacin and enrofloxacin analysis, in pork meat, are presented. In addition, diverse sample treatments for defatting, precipitate proteins, eliminate cations, and increase the ionic strength, were us…
Analysis of fumonisins in corn-based food by liquid chromatography with fluorescence and mass spectrometry detectors
Abstract The presented procedure involves an extraction with methanol–water, centrifugation and cleanup with immunoaffinity columns. A comparison study between fluorescence detector, mass spectrometry, and tandem mass spectrometry with a triple quadrupole (QqQ) analyzer using an electrospray ionisation interface for the determination of fumonisin B1 and B2 in corn-based products has been performed. Limits of quantification obtained by the three detectors were lower than the maximum levels established by European Commission. Liquid chromatography coupled to tandem mass spectrometry provides higher sensitivity (12 μg kg−1for fumonisins B1 and B2) when compared to mass spectrometry (40 μg kg−1…
Photo-induced fluorescence of magnesium derivatives of tetracycline antibiotics in wastewater samples
Abstract An analytical strategy, for the determination of tetracyclines (TCs), based on a HPLC system coupled with a photo-reactor followed by post-column derivatization was developed. Higher fluorescence emission after coupling the resulting photo-fragments with magnesium ions was observed for the determination of minocycline (MC), epitetracycline (ETC), tetracycline (TC) and doxycycline (DC). The manifold included a HPLC system with a photo-reactor (PTFE tubing helically coiled around a low-pressure mercury lamp), a mixing T-piece and a fluorescence detector. The derivatization reagent was delivered at 0.5 mL min −1 by a pump. After HPLC separation using a gradient system with a mobile ph…
Occurrence and risk assessment of zearalenone in flours from Portuguese and Dutch markets
The occurrence of zearalenone (ZEA) in different flours for human consumption, from the Portuguese and Dutch markets, was evaluated. Good analytical performance was obtained through extraction with acetonitrile:water (90:10), clean-up with immunoaffinity columns, and detection and quantification by liquid chromatography-fluorescence detection. ZEA levels were determined in 48 samples to verify the compliance with the maximum permitted levels by European legislation. Two flour samples from Portugal exceeded the maximum limit established by EC. A major presence and levels in maize flours was shown. Coimbra (Portugal) and Utrecht (The Netherlands) samples showed that 37.5% of the samples were …