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Harju K.,University of Helsinki | Rapinoja M.-L.,University of Helsinki | Avondet M.-A.,SPIEZ LABORATORY | Arnold W.,SPIEZ LABORATORY | And 4 more authors.
Toxins | Year: 2015

Saxitoxin (STX) and some selected paralytic shellfish poisoning (PSP) analogues in mussel samples were identified and quantified with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample extraction and purification methods of mussel sample were optimized for LC-MS/MS analysis. The developed method was applied to the analysis of the homogenized mussel samples in the proficiency test (PT) within the EQuATox project (Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk). Ten laboratories from eight countries participated in the STX PT. Identification of PSP toxins in naturally contaminated mussel samples was performed by comparison of product ion spectra and retention times with those of reference standards. The quantitative results were obtained with LC-MS/MS by spiking reference standards in toxic mussel extracts. The results were within the z-score of ±1 when compared to the results measured with the official AOAC (Association of Official Analytical Chemists) method 2005.06, pre-column oxidation high-performance liquid chromatography with fluorescence detection (HPLC-FLD) © 2015 by the authors; licensee MDPI, Basel, Switzerland.


PubMed | Marine Institute of Ireland, Finnish Environment Institute, University of Helsinki, ChemStat and SPIEZ LABORATORY
Type: Evaluation Studies | Journal: Toxins | Year: 2015

A saxitoxin (STX) proficiency test (PT) was organized as part of the Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk (EQuATox) project. The aim of this PT was to provide an evaluation of existing methods and the European laboratories capabilities for the analysis of STX and some of its analogues in real samples. Homogenized mussel material and algal cell materials containing paralytic shellfish poisoning (PSP) toxins were produced as reference sample matrices. The reference material was characterized using various analytical methods. Acidified algal extract samples at two concentration levels were prepared from a bulk culture of PSP toxins producing dinoflagellate Alexandrium ostenfeldii. The homogeneity and stability of the prepared PT samples were studied and found to be fit-for-purpose. Thereafter, eight STX PT samples were sent to ten participating laboratories from eight countries. The PT offered the participating laboratories the possibility to assess their performance regarding the qualitative and quantitative detection of PSP toxins. Various techniques such as official Association of Official Analytical Chemists (AOAC) methods, immunoassays, and liquid chromatography-mass spectrometry were used for sample analyses.


PubMed | Marine Institute of Ireland, University of Helsinki, ChemStat and SPIEZ LABORATORY
Type: Journal Article | Journal: Toxins | Year: 2015

Saxitoxin (STX) and some selected paralytic shellfish poisoning (PSP) analogues in mussel samples were identified and quantified with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample extraction and purification methods of mussel sample were optimized for LC-MS/MS analysis. The developed method was applied to the analysis of the homogenized mussel samples in the proficiency test (PT) within the EQuATox project (Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk). Ten laboratories from eight countries participated in the STX PT. Identification of PSP toxins in naturally contaminated mussel samples was performed by comparison of product ion spectra and retention times with those of reference standards. The quantitative results were obtained with LC-MS/MS by spiking reference standards in toxic mussel extracts. The results were within the z-score of 1 when compared to the results measured with the official AOAC (Association of Official Analytical Chemists) method 2005.06, pre-column oxidation high-performance liquid chromatography with fluorescence detection (HPLC-FLD).


PubMed | University of Lausanne, Ecole Polytechnique Federale de Lausanne, Institute for Food science IFS, ChemStat and 2 more.
Type: Journal Article | Journal: The British journal of nutrition | Year: 2015

Postprandial inflammation is an important factor for human health since chronic low-grade inflammation is associated with chronic diseases. Dairy products have a weak but significant anti-inflammatory effect on postprandial inflammation. The objective of the present study was to compare the effect of a high-fat dairy meal (HFD meal), a high-fat non-dairy meal supplemented with milk (HFM meal) and a high-fat non-dairy control meal (HFC meal) on postprandial inflammatory and metabolic responses in healthy men. A cross-over study was conducted in nineteen male subjects. Blood samples were collected before and 1, 2, 4 and 6h after consumption of the test meals. Plasma concentrations of insulin, glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol, TAG and C-reactive protein (CRP) were measured at each time point. IL-6, TNF- and endotoxin concentrations were assessed at baseline and endpoint (6h). Time-dependent curves of these metabolic parameters were plotted, and the net incremental AUC were found to be significantly higher for TAG and lower for CRP after consumption of the HFM meal compared with the HFD meal; however, the HFM and HFD meals were not different from the HFC meal. Alterations in IL-6, TNF- and endotoxin concentrations were not significantly different between the test meals. The results suggest that full-fat milk and dairy products (cheese and butter) have no significant impact on the inflammatory response to a high-fat meal.


Worbs S.,Robert Koch Institute | Fiebig U.,Robert Koch Institute | Zeleny R.,European Commission | Schimmel H.,European Commission | And 3 more authors.
Toxins | Year: 2015

In the framework of the EU project EQuATox, a first international proficiency test (PT) on the detection and quantification of botulinum neurotoxins (BoNT) was conducted. Sample materials included BoNT serotypes A, B and E spiked into buffer, milk, meat extract and serum. Different methods were applied by the participants combining different principles of detection, identification and quantification. Based on qualitative assays, 95% of all results reported were correct. Successful strategies for BoNT detection were based on a combination of complementary immunological, MS-based and functional methods or on suitable functional in vivo/in vitro approaches (mouse bioassay, hemidiaphragm assay and Endopep-MS assay). Quantification of BoNT/A, BoNT/B and BoNT/E was performed by 48% of participating laboratories. It turned out that precise quantification of BoNT was difficult, resulting in a substantial scatter of quantitative data. This was especially true for results obtained by the mouse bioassay which is currently considered as “gold standard” for BoNT detection. The results clearly demonstrate the urgent need for certified BoNT reference materials and the development of methods replacing animal testing. In this context, the BoNT PT provided the valuable information that both the Endopep-MS assay and the hemidiaphragm assay delivered quantitative results superior to the mouse bioassay. © 2015 by the authors; licensee MDPI, Basel, Switzerland.


PubMed | toxogen GmbH, ChemStat, European Commission and Robert Koch Institute
Type: Journal Article | Journal: Toxins | Year: 2015

In the framework of the EU project EQuATox, a first international proficiency test (PT) on the detection and quantification of botulinum neurotoxins (BoNT) was conducted. Sample materials included BoNT serotypes A, B and E spiked into buffer, milk, meat extract and serum. Different methods were applied by the participants combining different principles of detection, identification and quantification. Based on qualitative assays, 95% of all results reported were correct. Successful strategies for BoNT detection were based on a combination of complementary immunological, MS-based and functional methods or on suitable functional in vivo/in vitro approaches (mouse bioassay, hemidiaphragm assay and Endopep-MS assay). Quantification of BoNT/A, BoNT/B and BoNT/E was performed by 48% of participating laboratories. It turned out that precise quantification of BoNT was difficult, resulting in a substantial scatter of quantitative data. This was especially true for results obtained by the mouse bioassay which is currently considered as gold standard for BoNT detection. The results clearly demonstrate the urgent need for certified BoNT reference materials and the development of methods replacing animal testing. In this context, the BoNT PT provided the valuable information that both the Endopep-MS assay and the hemidiaphragm assay delivered quantitative results superior to the mouse bioassay.


Berger T.F.H.,Institute for Food science IFS | Luginbuhl W.,ChemStat
Accreditation and Quality Assurance | Year: 2016

The somatic cell count (SCC) of milk is one of the main indicators of the udder health status of lactating mammals and is a hygiene criterion of raw milk used to manufacture dairy products. An increase in SCC is regarded as one of the primary indicators of inflammation of the mammary gland. Therefore, SCC is relevant in food legislation as well as in the payment of ex-farm raw milk and it has a major impact on farm management and breeding programs. Its determination is one of the most frequently performed analytical tests worldwide. Routine measurements of SCC are almost exclusively done using automated fluoro-opto-electronic counting. However, certified reference materials for SCC are lacking, and the microscopic reference method is not reliable because of serious inherent weaknesses. A reference system approach may help to largely overcome these deficiencies and help to assure equivalence in SCC worldwide. The approach is characterised as a positioning system fed by different types of information from various sources. A statistical approach for comparing proficiency tests (PTs) by assessing them using a quality index PQ and assessing participating laboratories using a quality index PL, both deriving from probabilities, is proposed. The basic assumption is that PT schemes are conducted according to recognised guidelines in order to compute performance characteristics, such as z-scores, repeatability and reproducibility standard deviations. Standard deviations are compared with the method validation data from the ISO method. Input quantities close to or smaller than the reference data of the method validation or the assigned value of the PT result in values for PQ and PL close to the maximum value. Evaluation examples of well-known PTs show the practicability of the proposed approach. © 2016 The Author(s)


Pauly C.,Agroscope Liebefeld Posieux Research Station | Luginbuhl W.,ChemStat | Ampuero S.,Agroscope Liebefeld Posieux Research Station | Bee G.,Agroscope Liebefeld Posieux Research Station
Meat Science | Year: 2012

Alternatives to the common castration (C) practice of piglets are surgical castration under anaesthesia and rearing entire males (EM) or immunocastrates (IC). It is well established that boar taint hinders the breakthrough of these options. Less is known how avoiding surgical castration would affect carcass characteristics and pork quality. The objective of this meta-analysis was to estimate the impact of lack of castration on quality traits besides boar taint. The most marked effect of castration method and gender was found in lean meat and intramuscular fat percentage. Compared to EM, carcass leanness was estimated to be greater (P< 0.05) and intramuscular fat level lower (P< 0.05) than in C, IC and females. Regarding pork quality traits only the difference in shear force between IC and EM was of relevant magnitude. This meta-analysis revealed that the implementation of EM production should not be hindered by pork quality concerns. © 2012 Elsevier Ltd.


Worbs S.,Robert Koch Institute | Skiba M.,Robert Koch Institute | Bender J.,Robert Koch Institute | Zeleny R.,European Commission | And 3 more authors.
Toxins | Year: 2015

While natural intoxications with seeds of Ricinus communis (R. communis) have long been known, the toxic protein ricin contained in the seeds is of major concern since it attracts attention of those intending criminal, terroristic and military misuse. In order to harmonize detection capabilities in expert laboratories, an international proficiency test was organized that aimed at identifying good analytical practices (qualitative measurements) and determining a consensus concentration on a highly pure ricin reference material (quantitative measurements). Sample materials included highly pure ricin as well as the related R. communis agglutinin (RCA120) spiked into buffer, milk and meat extract; additionally, an organic fertilizer naturally contaminated with R. communis shred was investigated in the proficiency test. The qualitative results showed that either a suitable combination of immunological, mass spectrometry (MS)-based and functional approaches or sophisticated MS-based approaches alone successfully allowed the detection and identification of ricin in all samples. In terms of quantification, it was possible to determine a consensus concentration of the highly pure ricin reference material. The results provide a basis for further steps in quality assurance and improve biopreparedness in expert laboratories worldwide. © 2015 by the authors; licensee MDPI, Basel, Switzerland.


PubMed | ChemStat, European Commission and Robert Koch Institute
Type: Journal Article | Journal: Toxins | Year: 2015

While natural intoxications with seeds of Ricinus communis (R. communis) have long been known, the toxic protein ricin contained in the seeds is of major concern since it attracts attention of those intending criminal, terroristic and military misuse. In order to harmonize detection capabilities in expert laboratories, an international proficiency test was organized that aimed at identifying good analytical practices (qualitative measurements) and determining a consensus concentration on a highly pure ricin reference material (quantitative measurements). Sample materials included highly pure ricin as well as the related R. communis agglutinin (RCA120) spiked into buffer, milk and meat extract; additionally, an organic fertilizer naturally contaminated with R. communis shred was investigated in the proficiency test. The qualitative results showed that either a suitable combination of immunological, mass spectrometry (MS)-based and functional approaches or sophisticated MS-based approaches alone successfully allowed the detection and identification of ricin in all samples. In terms of quantification, it was possible to determine a consensus concentration of the highly pure ricin reference material. The results provide a basis for further steps in quality assurance and improve biopreparedness in expert laboratories worldwide.

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