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The results of a survey study on food samples produced from genetically modified soybean and maize collected from the Egyptian market are presented. Forty samples of soybean and 40 samples of maize products have been gathered randomly from markets in Cairo and Giza. The genetic modification was detected by polymerase chain reaction (PCR) using official detection methods according to section 35 of the German Foodstuffs Act. Samples were investigated for the presence of material derived from the following genetically modified organisms (GMOs) all of which are approved for food use in Europe: Roundup Ready soybean (RRS) and maize lines Bt176, Bt11, T25 and MON810. In addition, samples were examined in qualitative and quantitative analysis for the presence of material derived from the transgenic maize line StarLink (Aventis) which was approved for animal feed use exclusively in the US. Twenty % of 40 investigated soy samples contained Roundup Ready soybean; 15% of 40 maize samples tested positive for Bt176 and 12.5% positive for Bt11 maize. Furthermore, the presence of StarLink maize could clearly be demonstrated in four samples mixed with Bt176 and Bt11. The percentage of StarLink was less than 1% in quantitative analysis. The maize lines T25 and MON810 were not detected.

Nachdem in einer fruheren Arbeit der ESR-spektroskopische Nachweis von strahlenbehandelten Trockenfruchten besprochen wurde, wird in diesem Bericht die flussigchromatographische Bestimmung der Kohlenhydratfraktion dieser Fruchte vorgestellt und ein Zusammenhang zwischen der Zuckerzusammensetzung und den ESR-Signalstrukturen nachgewiesen.

Es werden zwei Methoden zur Identifizierung bestrahlter Huhnereier vorgestellt. Die Elektronenspinresonanz-Spektroskopie weist die strahlenspezifische Bildung eines Radikals in der Calcitmatrix der Eischale nach. Mit dieser Methode ist ein eindeutiger Nachweis bis weit unter die technologisch relevante Dosis moglich. Die Stabilitat des gebildeten Radikals wurde durch Lagerungsversuche von bis zu 6 Wochen uberpruft. Produkte, die kein oder nur sehr wenig Fett, jedoch einen hohen Proteinanteil enthalten, konnen mit HPLC auf die Bildung vono-Tyrosin untersucht werden. Bestrahlte Huhnereiweis-Proben zeigten im Gegensatz zu Kontrollproben einen Peak dieser Substanz im HPLC-Chromatogramm. Diese Methode konnte insbesondere bei der Untersuchung von pasteurisiertem Flussigeiweis von Bedeutung sein.

Die Elektronen-Spin-Resonanz-Spektroskopie kann zum Nachweis der Bestrahlung diverser Lebensmittelgruppen eingesetzt werden. In diesem Bericht werden die Ergebnisse des Bundesgesundheitsamtes bei der Entwicklung von ESR-Mesverfahren zur Identifizierung von strahlenbehandeltem Fleisch, Fisch und Frischobst sowie bestrahlten Trockenfruchten, Gewurzen und Nussen zusammengestellt.

Aqueous standard-solutions of L-alanine, L-glutamic acid, and L-proline do not reveal any increase of D-enantiomers after 30 min heating--neither by the conventional method on a hotplate, nor in a standard microwave oven. A specific "microwave effect" and, hence, a special consumer risk is, in contrast to recent assumptions, not detectable. Effects on the amino acids which were observed in conventionally heated samples are explained by higher heat-exposure during the treatment of these samples.

Detection of irradiated spices by electron spin resonance (ESR) measurements was not successful in the past because a central line of unknown origin was detected in the ESR-spectra of both irradiated and unirradiated samples. Identification of irradiated samples by measuring the increase of intensity of this signal after irradiation is limited because the signal intensity decreases over a period of some weeks of storage and reaches the range of unirradiated samples. By changing the measurement conditions (low microwave power) we could detect two additional lines on both sides of the main signal. This line pair appears only in the spectra of irradiated spices. A similar line pair was found in the spectra of irradiated nutshells and possibly derives from cellulose radicals in the sample. For some spices, especially paprika, the identification of irradiated samples by detecting these additional lines was possible even after relatively long periods of storage.

The response to ionizing radiation of thermoluminescence, chemiluminescence and viscosity of food was measured, and many specimens could be clearly distinguished from unirradiated samples up to several months after irradiation. Examples are given which show how to use the methods routinely for the purpose of food control. The results are based on long-term studies covering more than 50 spices and dried vegetables. Several experiments carried out with fresh or deep-frozen products appeared to be worthy of investigation. It is shown how exogenic effects (heat, water, UV, air, ethylene oxide) influence the luminescence. Finally, an assessment is given as to how the identification methods can be improved.

The results of a survey study on food samples produced from genetically modified soybean and maize collected from the Egyptian market are presented. Forty samples of soybean and 40 samples of maize products have been gathered randomly from markets in Cairo and Giza. The genetic modification was detected by polymerase chain reaction (PCR) using official detection methods according to section 35 of the German Foodstuffs Act. Samples were investigated for the presence of material derived from the following genetically modified organisms (GMOs) all of which are approved for food use in Europe: Roundup Ready soybean (RRS) and maize lines Bt176, Bt11, T25 and MON810. In addition, samples were examined in qualitative and quantitative analysis for the presence of material derived from the transgenic maize line StarLink (Aventis) which was approved for animal feed use exclusively in the US. Twenty % of 40 investigated soy samples contained Roundup Ready soybean; 15% of 40 maize samples tested positive for Bt176 and 12.5% positive for Bt11 maize. Furthermore, the presence of StarLink maize could clearly be demonstrated in four samples mixed with Bt176 and Bt11. The percentage of StarLink was less than 1% in quantitative analysis. The maize lines T25 and MON810 were not detected.

While in a previous work the ESR spectroscopic detection of irradiated dried fruits was reported, in this paper liquid chromatographic determination of the carbohydrate fraction of these fruits is introduced and connected with the ESR results. After irradiation of dried fruits three different types of ESR spectra are observed. In most cases the dried fruits can be attached to these various types by means of their sugar composition. It was also found that the ESR spectra observed for sucrose-rich fruits are very similar to that of pure sucrose. The structure of the ESR spectra can change with storage. Probably, radical rearrangement reactions in the samples are responsible for these changes.

Pasteurized egg products (whole egg, egg yolk and egg white) were tested for irradiation treatment in the German food control laboratories in Oldenburg/Niedersachsen and Kassel/Hessen as well as in the food irradiation laboratory of the German federal health office. Gas chromatographic/mass spectrometric measurements on the fat components of egg-products showed clearly whether the product had been irradiated or not. While in unirradiated samples no traces of special hydrocarbons (according to the fatty acid composition of egg) and no traces of the irradiation-specific compound 2-Dodecyl-cyclobutanone were found, irradiated control samples as well as products of two Belgian suppliers contained these substances. Additionally, regarding the rather high time consumption of gas chromatography, electron spin resonance (ESR)-measurements were carried out on the packaging material of egg products. Irradiated packaging material (cellulose) could be easily detected by the appearance of a signal pair in the ESR spectrum (cellulose radical). ESR measurements are very fast and easy to perform so that this method can be used for screening. Microbiological investigations showed remarkably reduced total numbers of microorganisms for some irradiated samples, but the microbiological status is influenced by other factors like storage-time and -temperature, so that microbiological tests can not be used successfully for screening on irradiation treatment.

Electron spin resonance spectroscopy can be used for the detection of irradiation of various groups of foodstuffs. The results of ESR-measurements on irradiated meat and fish and fresh fruit, as well as dried fruit, spices and nuts as performed by the food irradiation laboratory of the German Federal Health Office are summarized in this report. For the detection of irradiated meat and fish, we examined the bones. Using the results from 10 different animal bones, we were able to develop an official method according to the German law section 35 LMBG. A similar routine method for fish will be established in 1992 (at the moment, an intercomparison with German food control laboratories is in progress). Irradiated dried fruit can be identified easily, because unirradiated samples give no ESR-spectra, while irradiated fruit show a partially resolved spectrum, which is caused by radiation induced sugar radicals. Interestingly, the structure of the resulting spectra is not identical for all irradiated species of fruit. We found three different types of ESR-spectra for irradiated dried fruit. Irradiated nutshells show an ESR-spectrum which reveals two additional lines (from cellulose-radicals) beside the main signal, while unirradiated samples show only the main signal. An official method for identifying irradiated nuts will be proposed in 1992. Irradiation specific ESR-signals of the cellulose radical were not only found for nutshells but also for fresh fruit and some spices, while most of the irradiated spices and herbs could not be identified by ESR-measurements.

Aqueous standard-solutions of L-alanine, L-glutamic acid, and L-proline do not reveal any increase of D-enantiomers after 30 min heating--neither by the conventional method on a hotplate, nor in a standard microwave oven. A specific "microwave effect" and, hence, a special consumer risk is, in contrast to recent assumptions, not detectable. Effects on the amino acids which were observed in conventionally heated samples are explained by higher heat-exposure during the treatment of these samples.

Detection of irradiated spices by electron spin resonance (ESR) measurements was not successful in the past because a central line of unknown origin was detected in the ESR-spectra of both irradiated and unirradiated samples. Identification of irradiated samples by measuring the increase of intensity of this signal after irradiation is limited because the signal intensity decreases over a period of some weeks of storage and reaches the range of unirradiated samples. By changing the measurement conditions (low microwave power) we could detect two additional lines on both sides of the main signal. This line pair appears only in the spectra of irradiated spices. A similar line pair was found in the spectra of irradiated nutshells and possibly derives from cellulose radicals in the sample. For some spices, especially paprika, the identification of irradiated samples by detecting these additional lines was possible even after relatively long periods of storage.

The radiation-induced increase of serum amylase is investigated in 41 patients following either whole body irradiation or irradiation of the head- and neck-region. The radiation treatment caused a dose-independent serum amylase increase up to 80 times of the preirradiation measured in controls. This increase can only be induced if the salivary glands are within the radiation field. An isoenzyme analysis differentiated between salivary and pancreatic amylase. It was shown that also in case of whole body irradiation pancreatic proteins either contribute only to a small extent to the increase or show no recognizable change. Although great variations in radiation response remain, the increase of serum amylase produced by salivary glands is highly significant and serves as a bioindicator for radiation exposures.

Quality was controlled of seven different 99Mo/99mTc generators sold in the Federal Republic of Germany, which were all loaded with fission molybdenum. Aim of the work was to test the 99mTc eluates for their radionuclidic and radiochemical purity. Furthermore, the 99Mo content of the aluminium oxide column was measured. Determination of the elution efficiency, measurement of the pH-value of the eluate as well as a test to detect soluble aluminium in the eluate were also performed. In addition to the chemical and physical examinations, application, quality of accessories and their practicability were tested at all generators. The methods of analysis chosen were, among others, gamma spectrometry and thin-layer chromatography; the measuring methods were a site-sensitive proportional counter (measurement of the distribution of radioactivity of the chromatograms) and atomic absorption spectrometry (AI content of the eluates). The quality control of the 99mTc eluates had satisfying results. The eluates showed – with one exception – high and sufficient radionuclidic purity and very good radiochemical purity. A considerable overload of the columns with 99Mo at the time of reference was not found. The elution yields with values between 85 and 122% were in good agreement with the requirements. All eluates had pH-values between 5.0 and 6.5, and an aluminium content below 1 μg/ml. The generators had good performance and proved generally to be a reliable source of 99mTc-pertechnetate. The application was safe and, with some exceptions, fulfilled the requirements. Die Qualitatskontrolle wurde an sieben verschiedenen in der Bundesrepublik Deutschland kommerziell vertriebenen 99Mo/99mTc Generatoren, die alle mit Spaltmolybdan beladen waren, durchgefuhrt. Ziel dieser Arbeit war es, die gewonnenen 99mTc Eluate hinsichtlich ihrer radionuklearen und radiochemischen Reinheit zu uberprufen. Weiterhin wurde die Beladung der Aluminiumoxidsaule mit 99Mo gemessen. Bestimmung der Elutionsausbeute, Messung des pH-Wertes im Eluat sowie die Prufung auf losliches Aluminium im Eluat wurden ebenfalls vorgenommen. Neben den radiochemischen und radionuklearen Untersuchungen wurde auserdem an allen Generatoren deren Handhabung, Qualitat des Zubehors sowie dessen Praktikabilitat getestet. Als Analysenmethoden wurden unter anderen die Gammaspektrometrie und die Dunnschichtchromatographie, als Mesverfahren ein ortsempfindlicher Proportionalzahler (Messung der Radioaktivitatsverteilung auf den Chromatogrammen) sowie die Atomabsorptionsspektrometrie (Al-Gehalt der Eluate) gewahlt. Es zeigte sich, das die Qualitat der 99mTc Eluate zufriedenstellend war. Die Eluate zeigten mit einer Ausnahme hohe und ausreichende radionukleare Reinheit und sehr gute radiochemische Reinheit. Eine nennenswerte Uberladung der Saule mit 99Mo zum Referenzzeitpunkt konnte nicht festgestellt werden. Die Elutionsausbeuten lagen mit Werten zwischen 85 und 122% im Rahmen der gestellten Forderungen. Alle Eluate hatten pH-Werte zwischen 5,0 und 6,5 und einen Aluminiumgehalt unter 1 μg/ml. Die Generatoren erbrachten eine gute Leistung und erwiesen sich weitgehend als zuverlassige Quelle fur die Erzeugung von 99mTc-Pertechnetat. Die Handhabung war sicher und erfullte mit wenigen Ausnahmen die gestellten Anspruche.

Quality was controlled of seven different 99Mo/99mTc generators sold in the Federal Republic of Germany, which were all loaded with fission molybdenum. Aim of the work was to test the 99mTc eluates for their radionuclidic and radiochemical purity. Furthermore, the 99Mo content of the aluminium oxide column was measured. Determination of the elution efficiency, measurement of the pH-value of the eluate as well as a test to detect soluble aluminium in the eluate were also performed. In addition to the chemical and physical examinations, application, quality of accessories and their practicability were tested at all generators. The methods of analysis chosen were, among others, gamma spectrometry and thin-layer chromatography; the measuring methods were a site-sensitive proportional counter (measurement of the distribution of radioactivity of the chromatograms) and atomic absorption spectrometry (Al content of the eluates). The quality control of the 99mTc eluates had satisfying results. The eluates showed - with one exception - high and sufficient radionuclidic purity and very good radiochemical purity. A considerable overload of the columns with 99Mo at the time of reference was not found. The elution yields with values between 85 and 122% were in good agreement with the requirements. All eluates had pH-values between 5.0 and 6.5, and an aluminium content below 1 microgram/ml. The generators had good performance and proved generally to be a reliable source of 99mTc-pertechnetate. The application was safe and, with some exceptions, fulfilled the requirements.