Biomedical subjects

A Boenke

Publications and source records attributed to A Boenke.

At least 19 recordsLinked to original sources

PubMed2001

Contribution of European research to risk analysis.

The European Commission's, Quality of Life Research Programme, Key Action 1-Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety, of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches, harmonization of risk assessment principles methodologies and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries, to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women, evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.

Diet↗

PubMed2001

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study.

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.

Animals↗

PubMed2001

Quality of Life Programme--food, nutrition, and health--projects promotion.

The EC Quality of Life Programme (QoL), Key Action 1--Food, Nutrition & Health aims at providing a healthy, safe, and high-quality food supply leading to reinforced consumer's confidence in the safety of the European food. Key Action 1 is currently supporting several European projects investigating analytical methods for food control including sensors, risk analysis, and food safety standardisation. Their objectives range from the development and validation of prevention strategies for mycotoxin formation via the development of a communication platform for Genetically Modified Organisms (GMO), validation and standardisation of diagnostic Polymerase Chain Reaction (PCR) for food-borne pathogens, up to the evaluation of the potential cancer-preventing activity of pro- and pre-biotic ("SYNBIOTIC") combinations in human volunteers. This paper also informs on future research needs in food safety.

Consumer Product Safety↗

PubMed2000

An Internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics.

An internet website (http:¿cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-of-charge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.

Data Display↗

PubMed2000

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis.

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four post-column derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49 mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34 mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX-5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.

Animals↗

PubMed1998

Establishment of a reference collection of additives and an analytical handbook of reference data to support enforcement of EU regulations on food contact plastics.

A collection has been made of additives that are required as analytical standards for enforcement of European Union legislation on food contact plastics. The 100 additives have been characterized by mass spectrometry, infra-red spectroscopy and proton nuclear magnetic resonance spectroscopy to provide reference spectra. Gas chromatographic retention times have been recorded to facilitate identification by retention index. This information has been further supplemented by physico-chemical data. Finally, chromatographic methods have been used to indicate the presence of any impurities in the commercial chemicals. Samples of the reference substances are available on request and the collection of spectra and other information will be made available in printed format and on-line through the Internet. This paper gives an overview of the work done to establish the reference collection and the spectral atlas, which together will assist enforcement laboratories in the characterization of plastics and the selection of analytical methods for additives that may migrate.

Chromatography, Gas↗

PubMed1997

An intercomparison of methods for the determination of ochratoxin A in pig kidney.

The preparation of two pig kidney materials is described, together with a report on the results of an intercomparison study of methods to determine ochratoxin A levels in these materials. The materials were prepared, and the intercomparison study carried out within the European Commission. Measurements and Testing Programme, which is the successor of the Community Bureau of Reference (BCR). The materials were prepared from blank and naturally-contaminated pig kidneys and were freeze-dried. Details are given on the freeze-drying and packaging procedure, and the checks to ensure homogeneity and stability of the freeze-dried materials. The intercomparison study involved 20 European laboratories, which analysed the naturally-contaminated (freeze-dried) sample (ochratoxin A content approximately 10 micrograms/ kg based on fresh weight) and the 'blank' sample (ochratoxin A content < 0.6 microgram/kg based on fresh weight) using a variety of procedures for extraction and clean-up. All laboratories used HPLC as the determinative step. Recoveries were found to range from 43 to 128%. The study highlighted problems with recovery of spiked ochratoxin A from freeze-dried pig kidney material. There is a clear need to improve analytical performance, particularly with respect to the extraction efficiency from this type of matrix.

Animals↗

PubMed1997

Ochratoxin A in wheat: certification of two reference materials.

The preparation of two wheat reference materials and the certification of their ochratoxin A content is described. The materials were prepared and certified within the European Commission. Measurements and Testing Programme (M&T). The first and second phases of this project, two intercomparisons of procedures for the determination of ochratoxin A in wheat, at levels of approximately 13 micrograms/kg, and 7 micrograms/kg, respectively have already been reported. This paper describes the work carried out in certification of the ochratoxin A content (mass fraction) of two wheat reference materials: a blank wheat CRM 471, and a contaminated wheat, CRM 472. These materials were prepared for use in the second intercomparison referred to above and reported previously. Reference material CRM 472 was prepared from naturally-contaminated wheat blended with the blank wheat (CRM 471). Details are given of the milling, blending and packaging procedure, and the checks to ensure homogeneity and stability of the material. The certification exercise was carried out by 15 laboratories using a variety of extraction and clean-up procedures, and the certified ochratoxin A content (mass fraction) of CRM 471 was < 0.6 microgram/kg. The value for CRM 472 was 8.2 micrograms/kg with an uncertainty of 1.0 microgram/kg.

Calibration↗

PubMed1996

Beta-agonists in animal feed. I: First intercomparison of methods of analysis for clenbuterol in animal feed materials.

The European Commission, Measurement and Testing Programme (BCR) has initiated a project to improve the methodology for analysis of beta-agonists in animal feeding stuffs. An intercomparison of methods for clenbuterol in animal feed is described. The study involved 13 European laboratories which analysed a blank feed and three feed samples with three different levels of clenbuterol contamination. The participants used a variety of extraction (organic or aqueous solvents), clean-up (liquid-liquid, silica and C-18 solid phase and immuno-affinity chromatography) and end-point detection (HPLC, GC-MS and TLC) steps. The purpose of this study was to identify and to quantify clenbuterol. The coefficient of variation from all the results for the low level (25 micrograms/kg) was 39%, for the intermediate level (100 micrograms/kg) 52% and for the high level (1000 micrograms/kg) 35%. The study showed that the initial extraction, the modular clean-up step and their compatibility to the HPLC and the GC-MS determination step were critical steps.

Adrenergic beta-Agonists↗

PubMed1996

Beta-agonists in animal feed. II: Optimization of the extraction.

New projects of the European Commission, Measurement and Testing Programme (BCR) were set up in order to develop a modular sample preparation system for the determination of beta-agonists and animal feeds. Three phases are included: an extraction study, a clean-up study and finally a Second Intercomparison. This paper describes the extraction study in which four laboratories were involved. A total of 33 extraction conditions were tested regarding their yield on clenbuterol and salbutamol, their compatibility towards several clean-up and chromatographic end-methods and the influence of undesired coextractives. The conditions differed with respect to five factors: with or without organic solvent, temperature, pH, agitation and centrifugation. Their influence was examined via a ruggedness-test approach. A unique set-up allowed the combination of individual results in a complete factorial design. The addition of an organic solvent was found to be the most important factor. Interactions between factors were also studied. The best combinations of factors regarding the extraction are given. Finally limits for applicability and influence of organic solvents, pH and temperature were evaluated in a fifth laboratory towards enzyme immunoassay as detection method.

Acetates↗

PubMed1996

Ochratoxin A in wheat: a second intercomparison of procedures.

The European Commission, Measurements and Testing Programme (BCR) has undertaken a project to improve methodology and to prepare certified reference materials for ochratoxin A determination. The first phase of this project, an intercomparison of procedures for the determination of ochratoxin A in wheat, at a content of approximately 13 micrograms/kg, has already been reported. The second intercomparison study, described in this paper, involved 26 European laboratories, from 11 countries, which analysed wheat naturally contaminated at a level of approximately 7 micrograms/kg, and a 'blank' wheat sample (ochratoxin A content < 0.2 microgram/kg). The participants used a variety of procedures which involved different extraction solvents and clean-up procedures. All laboratories used HPLC as the determinative step. Some laboratories also used immunoaffinity column clean-up in comparison with their normal method. Recoveries of the normal methods used by laboratories ranged from 58 to 114%; only three laboratories obtained recoveries outside the accepted range of 70 to 110%. Recoveries of the immunoaffinity column methods, using two sources of column, ranged from 58 to 114% for one and from 4 to 86% for the other. The between-laboratory reproducibility coefficient of variation for all results was 34% for the normal methods, and 34 and 42% for the two types of immunoaffinity columns. It was noted that, after the results were corrected for spike recovery, some laboratories became outliers owing to low spike recoveries. Further investigations of the spiking protocols used by each laboratory showed that the time left for evaporation of the spiking solvent was crucial to the recovery obtained.

Chromatography, High Pressure Liquid↗

PubMed1996

beta-agonists in animal feed. III: Optimization of the clean-up and the end-determination step.

This study represents the second part of an interlaboratory study intended to develop an official modular Community confirmatory method for the detection of beta-agonists in animal feed. Homogeneous pools of primary extracts were prepared by means of an extraction module based on the conclusions of a previous part of this work. The primary extracts were further processed by four laboratories each using a different clean-up scheme. The final extracts thus obtained were cross-distributed between the same laboratories and measured either by GCMS or HPLC. Two laboratories (B and D) applied separate clean-up schemes for clenbuterol and salbutamol. All clean-up schemes for clenbuterol were found to be compatible with all end-determination steps. In contrast, for salbutamol clean-up method D was found not to be compatible with the end-determination steps applied by laboratories B and C. The results of this study have clearly demonstrated that the clean-up methods for both clenbuterol and salbutamol applied by laboratory B yielded superior recoveries with an acceptable standard deviation. Therefore, in conclusion to this study, the participating laboratories recommend the clean-up schemes applied by laboratory B to serve as part of the official Community confirmatory method.

Adrenergic beta-Agonists↗

PubMed1995

BCR- and M&T-activities in the area of mycotoxin analysis in food and feedstuffs.

In order to avoid undesirable side effects such as high contents of mycotoxins in food and feed, measurements at critical steps of the food and feed production chain are performed. These measurements need to be accurate and precise to satisfy these aims. The accuracy and precision requirements to measurements form the basis of the Bureau Communautaire de Référence (BCR)-and Measurements and Testing (M&T)-Projects. Such projects aim to improve and/or develop analytical methodology, sampling plans, to harmonise agreement of results between European Union Member States and to prepare suitable certified reference materials (CRMs). The selection of the matrix CRMs and their corresponding level of mycotoxin contamination is made on the basis of requirements of the applied analytical procedures, stability requirements, regulations, norms, and inter-or intra-trade agreements which are in relation to quality specifications of imported and/or exported goods. The availability of appropriate matrix CRMs is not only a prerequisite for the implementation of directives and norms. It allows the validation of new methods and provides a possible solution to trade disputes, means for the statistical control of analytical results, tools for laboratory accreditation, and it is the basis for harmonisation and traceability of proficiency schemes.

Food Analysis↗

PubMed1995

Occurrence of fumonisins in Europe and the BCR--measurements and testing projects.

Fumonisins are mycotoxins mainly produced by Fusarium moniliforme, one of the most prevalent seed-borne fungi of maize. Strains of Fusarium moniliforme isolated from cereals in Europe produced in cultures high levels (up to 4 mg/g) of fumonisins B1 and B2 (FB1 and FB2). FB1 and FB2 have been found in maize and maize-based foods and feeds in most European countries. In Italy these mycotoxins have been directly involved in a fatal outbreak of equine leukoencephalomalacia, and have been found at different levels in most maize-based food products, including polenta--a staple food in a region with high incidence of esophageal cancer. The European Commission, Community Bureau of Reference (BCR) and Measurements and Testing Programme (M&T), has undertaken two consecutive intercomparison studies, involving over 20 laboratories from 12 European countries, to improve the quality of fumonisins analysis at European level. The first study consisted in the evaluation of the determination of fumonisins in an unknown solution, while the second one involved the analytical methodology for fumonisins in contaminated and blank maize samples. A definite improvement in the performance of the different laboratories has been observed in the second study. In view of the production of reference materials certified for their fumonisins contents, new analytical procedures need to be developed.

Food Microbiology↗

PubMed1995

Ochratoxin A in cereals and the BCR-M&T-projects.

Reliable analytical procedures and certified reference materials are essential for the establishment and enforcement of tolerance levels for ochratoxin A in foods. The inadequacy of analytical procedures, together with the need for certified reference materials, led the Commission of the European Communities Community Bureau of Reference (BCR) to undertake a project to prepare suitable reference materials for ochratoxin A in wheat, in order to improve methodology and to harmonise agreement of results between member states. The first intercomparison study indicated problems in the analysis due to the influence of co-extractives in the matrix, and demonstrated that further work was necessary to improve recovery, clean-up and reproducibility. The second intercomparison study, in the EC Measurements and Testing Programme, correlated the performance of the different methods for ochratoxin A measurement in a separate batch of contaminated wheat, and compared novel immunoaffinity column methods with the standard laboratory methods. Results were obtained from 26 laboratories within 11 European countries, which therefore gives a good representation of the scope of methods currently used in Europe. Considerable improvements in the determination of ochratoxin A were noted compared with the first intercomparison study.

Carcinogens↗

PubMed1995

Measurement of glucosinolates in rapeseeds.

Several ring tests have been organized by the International Organisation for Standardization (ISO) and the Measurement and Testing Programme (BCR) for improving glucosinolate methods. Finally, HPLC of desulphoglucosinolates is recommended by ISO, the European Committee for Standardization (CEN), and the European Commission (EC) as the official method. X-ray fluorescence has also become particularly common for fast analysis. After checking stability of intact glucosinolates in whole rapeseeds, the BCR has three reference materials (CRM 366, CRM 190, CRM 367) available, certified for their total glucosinolate and sulphur contents. Currently, the Measurement and Testing Programme is supporting a research project concerning the stability of desulphoglucosinolates and intact glucosinolates extracts. At the present time, best results are observed with lyophilized extracts sealed in brown glass ampoules and stored at -18 degrees C.

Brassica↗

PubMedDate not supplied

The preparation, validation and certification of the aflatoxin content of two peanut butter reference materials.

The preparation of two peanut butter reference materials and the certification of their aflatoxins B1, B2, G1, G2 and total aflatoxin contents is described. The materials were prepared and certified within the BCR Programme of the Commission of the European Community as part of a broad activity to improve accuracy and agreement of measurements of importance in food and agriculture (Wagstaffe and Belliardo 1990). Reference material RM 385 was prepared from naturally contaminated peanuts, roasted and ground into a paste and then blended with uncontaminated peanut butter to achieve the desired aflatoxin concentrations. Details are given of the blending and canning procedure, and the checks to ensure homogeneity and stability of the material. Reference material RM 401 was similarly prepared but from an uncontaminated peanut butter. The certification exercise was carried out by nine laboratories using a variety of extraction and clean-up procedures, but all using high performance liquid chromatography (HPLC) as the determinative stage although operating under a variety of chromatographic conditions. RM 385 was certified as containing aflatoxins B1, B2, G1 and G2 at levels of 7.0 +/- 0.8 micrograms/kg, 1.1 +/- 0.2 micrograms/kg, 1.7 +/- 0.3 micrograms/kg and 0.3 +/- 0.2 micrograms/kg respectively (total aflatoxin content of 10.1 +/- 1.5 micrograms/kg) and RM 401 as containing aflatoxin B1, B2 and G2 at less than 0.2 micrograms/kg and aflatoxin G1 at less than 0.3 micrograms/kg (total aflatoxin content less than 0.9 micrograms/kg). The materials are intended for the verification of methods used to determine aflatoxins in nuts and nut products.

Aflatoxin B1↗

PubMedDate not supplied

Deoxynivalenol in wheat and maize flour reference materials. 1. An intercomparison of methods.

To provide a basis for the certification of wheat and maize flour reference materials containing deoxynivalenol, a series of three preliminary intercomparisons of methods was carried out between 1985 and 1988. The first intercomparison, involving 10 laboratories was designed to examine the determinative step and used a solution of deoxynivalenol in ethyl acetate and a spiked wheat extract solution. The second intercomparison involving 13 laboratories established minimum extraction times for naturally contaminated samples, demonstrated the absence of matrix effects in purified extracts and showed that there was no evidence of differences in the use of any of three different end determinations. The third intercomparison involving 15 laboratories used naturally contaminated cereals and acted as a preliminary to the final certification exercise. Over a period of four years there was a steady improvement in the range of results submitted by participants thought to be due to the application of improved analytical methods, increased expertise in the analysis and through experience gained through the intercomparisons.

Chromatography, Gas↗