RESUMEN
In 2013 the Dutch authorities issued a warning against a dietary supplement that was linked to 11 reported adverse reactions, including heart problems and in one case even a cardiac arrest. In the UK a 20-year-old woman, said to have overdosed on this supplement, died. Since according to the label the product was a herbal mixture, initial LC-MS/MS analysis focused on the detection of plant toxins. Yohimbe alkaloids, which are not allowed to be present in herbal preparations according to Dutch legislation, were found at relatively high levels (400-900 mg kg(-1)). However, their presence did not explain the adverse health effects reported. Based on these effects the supplement was screened for the presence of a ß-agonist, using three different biosensor assays, i.e. the validated competitive radioligand ß2-adrenergic receptor binding assay, a validated ß-agonists ELISA and a newly developed multiplex microsphere (bead)-based ß-agonist assay with imaging detection (MAGPIX(®)). The high responses obtained in these three biosensors suggested strongly the presence of a ß-agonist. Inspection of the label indicated the presence of N-isopropyloctopamine. A pure standard of this compound was bought and shown to have a strong activity in the three biosensor assays. Analysis by LC-full-scan high-resolution MS confirmed the presence of this 'unknown known' ß3-agonist N-isopropyloctopamine, reported to lead to heart problems at high doses. A confirmatory quantitative analysis revealed that one dose of the preparation resulted in an intake of 40-60 mg, which is within the therapeutic range of this compound. The case shows the strength of combining bioassays with chemical analytical techniques for identification of illegal pharmacologically active substances in food supplements.
Asunto(s)
Agonistas de Receptores Adrenérgicos beta 3/envenenamiento , Antipirina/análogos & derivados , Depresores del Apetito/efectos adversos , Suplementos Dietéticos/efectos adversos , Contaminación de Alimentos , Cardiopatías/etiología , Preparaciones de Plantas/efectos adversos , Agonistas de Receptores Adrenérgicos beta 3/análisis , Alcaloides/análisis , Alcaloides/toxicidad , Anabolizantes/efectos adversos , Anabolizantes/química , Anabolizantes/envenenamiento , Anabolizantes/normas , Antipirina/análisis , Antipirina/envenenamiento , Depresores del Apetito/química , Depresores del Apetito/envenenamiento , Depresores del Apetito/normas , Técnicas Biosensibles , Suplementos Dietéticos/análisis , Suplementos Dietéticos/envenenamiento , Suplementos Dietéticos/normas , Inspección de Alimentos , Etiquetado de Alimentos , Enfermedades Transmitidas por los Alimentos/etiología , Enfermedades Transmitidas por los Alimentos/mortalidad , Enfermedades Transmitidas por los Alimentos/terapia , Cardiopatías/mortalidad , Cardiopatías/terapia , Hospitalización , Humanos , Internet , Países Bajos , Nootrópicos/efectos adversos , Nootrópicos/química , Nootrópicos/envenenamiento , Nootrópicos/normas , Pausinystalia/efectos adversos , Pausinystalia/química , Sustancias para Mejorar el Rendimiento/efectos adversos , Sustancias para Mejorar el Rendimiento/química , Sustancias para Mejorar el Rendimiento/envenenamiento , Sustancias para Mejorar el Rendimiento/normas , Preparaciones de Plantas/química , Preparaciones de Plantas/envenenamiento , Preparaciones de Plantas/normasRESUMEN
Coccidiostats are authorized in the European Union (EU) to be used as poultry feed additives. Maximum (residue) levels (M(R)Ls) have been set within the EU for consumer and animal protection against unintended carry-over, and monitoring is compulsory. This paper describes the single-laboratory validation of a previously developed multiplex flow cytometric immunoassay (FCIA) as screening method for coccidiostats in eggs and feed and provides and compares different approaches for the calculation of the cut-off levels which are not described in detail within Commission Decision 2002/657/EC. Comparable results were obtained between the statistical (reference) approach and the rapid approaches. With the most rapid approach, the cut-off levels for narasin/salinomycin, lasalocid, diclazuril, nicarbazin (DNC) and monensin in egg, calculated as percentages of inhibition (%B/B0), were 60, 32, 76, 80 and 84, respectively. In feed, the cut-off levels for narasin/salinomycin, lasalocid, nicarbazin (DNC) and monensin were 70, 64, 72 and 78, respectively, and could not be determined for diclazuril. For all analytes, except for diclazuril in feed, the rate of false positives (false non-compliant) in blank samples was lower than 1 %, and the rate of false negatives (false compliant) at the M(R)Ls was below 5 %. Additionally, very good correlations (r ranging from 0.994 to 0.9994) were observed between two different analysers, a sophisticated flow cytometer (FlexMAP 3D(®)) and a more cost-efficient and transportable planar imaging detector (MAGPIX(®)), hence demonstrating adequate transferability.
Asunto(s)
Alimentación Animal/análisis , Coccidiostáticos/análisis , Residuos de Medicamentos/análisis , Huevos/análisis , Citometría de Flujo/métodos , Inmunoensayo/métodos , Animales , PollosRESUMEN
This article presents a review of the current trends in the analysis of coccidiostats in various matrices, focusing principally on screening and rapid methods. Coccidiosis is an infectious disease having a high negative impact on the animal industry. Drugs are therefore necessary to prevent and/or to combat this disease. However, it is also of crucial importance that these veterinary drugs do not enter the human food chain. European legislation has therefore established the boundaries for the use of coccidiosats and has also addressed the unavoidable problem of cross-contamination of the feed, mainly caused by the use of the same production lines. Consequently there is a need for analytical methods and/or analytical strategies for the monitoring and control of the residues of anticoccidials, both in feed and in the resulting matrices for human consumption. In the frame of the European collaborative project CONffIDENCE, such attempts to establish the required analytical tools were made, which required beforehand a review of the state of the art in this domain. Aiming at this objective, in this review we consider the most interesting publications since 2000. In essence, both a rapid approach with mainly immunoassays and chromatographic methods were developed. To date, the obstacle to routine use of the first approach has been its inability to detect more than two compounds simultaneously, but recent developments in flow cytometry have made it possible to detect six coccidiostats at once. On the other hand, an increasingly popular approach for detecting multiple coccidiostats simultaneously is liquid chromatography coupled with tandem mass spectrometry. There remains a need to adapt these analytical methods to legislative requirements.
Asunto(s)
Técnicas de Química Analítica/métodos , Coccidiostáticos/análisis , Cadena Alimentaria , Drogas Veterinarias/análisis , Animales , Cromatografía Liquida , Coccidiostáticos/química , Contaminantes Ambientales/análisis , Ensayos Analíticos de Alto Rendimiento/tendencias , Humanos , Espectrometría de Masas en Tándem , Drogas Veterinarias/químicaRESUMEN
Coccidiostats are the only veterinary drugs still permitted to be used as feed additives to treat poultry for coccidiosis. To protect consumers, maximum levels for their presence in food and feed have been set by the European Union (EU). To monitor these coccidiostats, a rapid and inexpensive screening method would be a useful tool. The development of such a screening method, using a flow cytometry-based immunoassay, is described. The assay uses five sets of colour-coded paramagnetic microspheres for the detection of six selected priority coccidiostats. Different coccidiostats, with and without carrier proteins, were covalently coupled onto different bead sets and tested in combination with polyclonal antisera and with a fluorescent-labelled secondary antibody. The five optimal combinations were selected for this multiplex and a simple-to-use sample extraction method was applied for screening blank and spiked eggs and feed samples. A very good correlation (r ranging from 0.995 to 0.999) was obtained with the responses obtained in two different flow cytometers (Luminex 100 and FLEXMAP 3D). The sensitivities obtained were in accordance with the levels set by the EU as the measured limits of detection for narasin/salinomycin, lasalocid, diclazuril, nicarbazin (4,4'-dinitrocarbanilide) and monensin in eggs were 0.01, 0.1, 0.5, 53 and 0.1 µg/kg and in feed 0.1, 0.2, 0.3, 9 and 1.5 µg/kg, respectively.
Asunto(s)
Alimentación Animal/análisis , Coccidiostáticos/análisis , Huevos/análisis , Citometría de Flujo/métodos , Animales , Anticuerpos/análisis , Anticuerpos/inmunología , Coccidiostáticos/inmunología , Citometría de Flujo/economía , Inmunoensayo/economía , Inmunoensayo/métodos , Aves de Corral , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
A multi-mycotoxin immunoassay-using the MultiAnalyte Profiling (xMAP) technology-is developed and evaluated. This technology combines a unique color-coded microsphere suspension array, with a dedicated flow cytometer. We aimed for the combined detection of aflatoxins, ochratoxin A, deoxynivalenol, fumonisins, zearalenone and T-2-toxin in an inhibition immunoassay format. Sets of six mycotoxin-protein conjugates and six specific monoclonal antibodies were selected, and we observed good sensitivities and no cross-interactions between the assays in buffer. However, detrimental effects of the feed extract on the sensitivities and in some cases on the slopes of the curves were observed and different sample materials showed different effects. Therefore, for quantitative analysis, this assay depends on calibration curves in blank matrix extracts or on the use of a suitable multi-mycotoxin cleanup. To test if the method was suitable for the qualitative detection at EU guidance levels, we fortified rapeseed meal, a feed ingredient, with the six mycotoxins, and all extracts showed inhibited responses in comparison with the non-fortified sample extract. Contaminated FAPAS reference feed samples assigned for a single mycotoxin showed strong inhibitions in the corresponding assays but also often in other assays of the multiplex. In most cases, the presence of these other mycotoxins was confirmed by instrumental analysis. The multiplex immunoassay can be easily extended with other mycotoxins of interest, but finding a suitable multi-mycotoxin cleanup will improve its applicability.
RESUMEN
Sulfonamide antibiotics are applied in veterinary medicine for the treatment of microbial infections. For the detection of residues of sulfonamides in milk, a multi-sulfonamide flow cytometric immunoassay (FCI) was developed using the Luminex MultiAnalyte Profiling (xMAP) technology. In this automated FCI, a previously developed biotinylated multi-sulfonamide mutant antibody (M.3.4) was applied in combination with fluorescent beads, directly coated with a sulfathiazole derivative, and streptavidin-phycoerythrin (SAPE) for the detection. With this FCI, at least 11 different sulfonamides could be detected (more than 50% inhibition at the 100 ng mL(-1) level) and, after an incubation of 1h, measurements were rapid (10s per sample). For the application with raw milk, a 96-well microplate-based filtration step was included into the protocol to remove disturbing milk fat particles. Because of differences in sensitivity towards different sulfonamides, the FCI was considered and validated as a qualitative screening assay. For sulfadoxine, the most applied sulfonamide in Dutch dairy cattle, the detection capability (CCbeta) was <50 microg L(-1) and this level seems feasible for five other sulfonamides. For sulfadiazine, the CCbeta was <200 microg L(-1) and this level seems feasible for four other sulfonamides. A major advantage of the applied xMAP-technology, with its 100 different color-coded bead sets, is the possibility to develop multiplex immunoassays for the simultaneous detection of several antibiotics.
Asunto(s)
Citometría de Flujo/métodos , Inmunoensayo/métodos , Leche/química , Sulfonamidas/análisis , Animales , Tampones (Química) , Calibración , Leche/inmunología , Sensibilidad y Especificidad , Sulfonamidas/inmunología , TemperaturaRESUMEN
Genistein receives much attention because of its potential to prevent hormone-related cancer and cardiovascular diseases. Limited information is available on the pharmacokinetics of this compound like, for instance, their intestinal uptake by humans and systematic bioavailability. In this study, the fate of the absorption of genistein and its glycoside has been analysed in various isolated perfused gut segments of the rat. In all perfused gut segments the transport of genistein was higher compared to its glycoside. Furthermore, it appeared that the resorbate (i.e. serosal side) concentration of genistein was the highest in ileac segments, whereas the transport of genistein in the various other segments tested showed no difference between intestinal compartments. Less than 0.2% of genistin appeared in the resorbate fluid of all isolated gut segments. The main site of metabolism of genistein and its glycoside appears to be located in the jejunal compartment of the rat gut. About 38% of genistein and about 29% of genistin metabolised within 2h of perfusion. In the ileac and colonic intestinal segments, genistein metabolised for only 10%. For the first time, this study demonstrated that genistin could be metabolised by epithelial cells present in isolated colonic segments. However, the metabolites of genistin did not occur at the serosal side (the resorbate) of isolated colonic segments. We assume that there is no absorption of genistin and/or its metabolites in or through colonic tissue of the rat.