Rapid Analysis of Illegal Cationic Dyes in Foods and Surface Waters Using High Temperature Direct Analysis in Real Time High-Resolution Mass Spectrometry
Wen, Ruizhi ; Zeng, Dong ; Yang, Zihui ; Jiang, Le ; Ma, Ming ; Chen, Bo ; Beek, Teris A. Van - \ 2018
Journal of Agricultural and Food Chemistry 66 (2018)28. - ISSN 0021-8561 - p. 7542 - 7549.
crystal violet - direct analysis in real time - food safety - high-resolution mass spectrometry - illegal cationic dyes - induced phase separation extraction - malachite green - methylene blue - rhodamine B
A high temperature desorption (HTD) direct analysis in real time-high-resolution mass spectrometric (DART-HRMS) method was developed for the rapid analysis of four banned cationic dyes. Rhodamine B is used to dye foods, while malachite green, crystal violet, and methylene blue are added to fishponds as antimicrobials. A simple induced phase separation extraction was used to pretreat samples. The DART-HRMS method employed two temperature steps, i.e., 200 °C for drying, purification, and enrichment of sample solution and 500 °C for thermal desorption and ionization of analytes. The calibration curves of dyes in the range of 50-2000 ng/mL were linear using deuterated malachite green as an internal standard. The LODs vary for all analytes between 0.1 and 30 ppb depending on the matrix and experimental conditions. Through analyses of real samples, two chili powders and one chili oil were found to be contaminated by rhodamine B. The concentrations were comparable with those found by an HPLC-MS/MS method.
Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger
Tamayo Ramos, J.A. ; Berkel, W.J.H. van; Graaff, L.H. de - \ 2012
Microbial Cell Factories 11 (2012). - ISSN 1475-2859 - 11 p.
malachite green - fungal laccases - yellow laccase - phanerochaete-chrysosporium - pleurotus-ostreatus - filamentous fungi - blue - degradation - expression - nidulans
BACKGROUND: Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. RESULTS: The laccase-like multicopper oxidases McoA, McoB and McoG from the commonly used cell factory Aspergillus niger were homologously expressed, purified and analyzed for their biocatalytic potential. All three recombinant enzymes were monomers with apparent molecular masses ranging from 80 to 110 kDa. McoA and McoG resulted to be blue, whereas McoB was yellow. The newly obtained oxidases displayed strongly different activities towards aromatic compounds and synthetic dyes. McoB exhibited high catalytic efficiency with N,N-dimethyl-p-phenylenediamine (DMPPDA) and 2,2-azino-di(3-ethylbenzthiazoline) sulfonic acid (ABTS), and appeared to be a promising biocatalyst. Besides oxidizing a variety of phenolic compounds, McoB catalyzed successfully the decolorization and detoxification of the widely used textile dye malachite green. CONCLUSIONS: The A. niger McoA, McoB, and McoG enzymes showed clearly different catalytic properties. Yellow McoB showed broad substrate specificity, catalyzing the oxidation of several phenolic compounds commonly present in different industrial effluents. It also harbored high decolorization and detoxification activity with the synthetic dye malachite green, showing to have an interesting potential as a new industrial biocatalyst
Use of chemicals and biological products in Asian aquacultire and their potential environmental risks: a critical review
Rico, A. ; Satapornvanit, K. ; Haque, M.M. ; Min, J. ; Nguyen, P.T. ; Telfer, T. ; Brink, P.J. van den - \ 2012
Reviews in Aquaculture 4 (2012)2. - ISSN 1753-5123 - p. 75 - 93.
species sensitivity distributions - fresh-water - macrobrachium-rosenbergii - veterinary antibiotics - aquatic environment - malachite green - mangrove areas - shrimp ponds - toxicity - fish
Over the past few decades, Asian aquaculture production has intensified rapidly through the adoption of technological advances, and the use of a wide array of chemical and biological products to control sediment and water quality and to treat and prevent disease outbreaks. The use of chemicals in aquaculture farms has raised environmental concerns owing to their potential impacts on downstream aquatic ecosystems. Currently little is known about the environmental fate and effects of the chemicals used in Asian aquaculture. Consequently, we reviewed recent information on the use of chemical and biological products in the most important Asian aquaculture producing countries and briefly summarize their main potential environmental impacts. We provide an overview of the main factors controlling the use of these chemicals and describe the international risk assessment guidelines available for aquaculture chemicals. Finally, data gaps and research needs for their implementation in Asian countries are discussed. Our review aims to form a basis for developing environmental risk assessment studies of the chemicals used in Asian aquaculture.
Residue analysis of veterinary drugs and growth-promoting agents
Stolker, A.A.M. ; Zuidema, T. ; Nielen, M.W.F. - \ 2007
TrAC : Trends in Analytical Chemistry 26 (2007)10. - ISSN 0165-9936 - p. 967 - 979.
tandem mass-spectrometry - performance liquid-chromatography - animal-food products - malachite green - antiinflammatory drugs - confirmatory analysis - leucomalachite green - nitrofuran residues - biological matrices - hair analysis
Two major trends are observed in the analysis of veterinary drugs and growth-promoting agents. First is the selection of sample material for monitoring the use of registered veterinary drugs. Traditionally meat, kidney and liver were analyzed but, due to the food scandals in which meat was very often involved, the consumption of alternative products (e.g., eggs and fish) has become more popular and therefore more of interest for residue-monitoring programmes. Most food scandals started with contamination of animal feed, so feed has also gained interest for monitoring purposes. For the detection of unauthorized substances (e.g., growth-promoting agents), the matrix hair is frequently used because residues can be detected in hair even a long time after treatment. Second, the techniques used for residue analysis are moving from target-orientated methods, mainly based on liquid chromatography in combination with triple-quadrupole mass-spectrometric detection (LC-QqQ-MS), towards accurate mass full-scan MS techniques (e.g., time-of-flight (ToF)-MS and Fourier-transform(FT)-MS. Full-scan MS techniques enable retrospective analysis (i.e. without re-injecting the sample) and real multi-residue analysis (including different classes of veterinary drugs). The application of full-scan MS also has consequences for separation and extraction techniques, which have to be applicable to a broad range of compounds differing in physical and chemical properties. Experience shows that ToF-MS in combination with ultra-performance LC (UPLC) is very powerful for multi-residue analysis. The introduction of new MS techniques also has consequences for European Union (EU) criteria defined for confirmation of the identity of compounds. It is suggested that both mass-resolution and mass-accuracy data influence identity confirmation and both parameters should be implemented in the revision of European Commission Decision 2002/657/EC. (C) 2007 Elsevier Ltd. All rights reserved.