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Michael G. Kontominas - One of the best experts on this subject based on the ideXlab platform.
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Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials
Developments in food science, 2007Co-Authors: Kyriakos A Riganakos, D.a.e. Ehlermann, W D Koller, B. Bauer, Michael G. KontominasAbstract:Abstract Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap Technique and identified by combined gas chromatography-mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds proportionally increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. No significant changes were observed in the structure of polymer matrices as exhibited by IR spectra after irradiation of the materials at doses tested. Likewise, no significant changes were observed in gas permeability of plastics packaging materials after irradiation.
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Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials
Radiation Physics and Chemistry, 1999Co-Authors: Kyriakos A Riganakos, D.a.e. Ehlermann, W D Koller, B. Bauer, Michael G. KontominasAbstract:Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap Technique and identified by combined gas chromatography–mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. No significant changes were observed in the structure of polymer matrices as exhibited by IR spectra after irradiation of the materials at doses tested. Likewise, no significant changes were observed in O2, H2O and CO2 permeability values of plastic packaging materials after irradiation.
Kyriakos A Riganakos - One of the best experts on this subject based on the ideXlab platform.
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Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials
Developments in food science, 2007Co-Authors: Kyriakos A Riganakos, D.a.e. Ehlermann, W D Koller, B. Bauer, Michael G. KontominasAbstract:Abstract Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap Technique and identified by combined gas chromatography-mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds proportionally increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. No significant changes were observed in the structure of polymer matrices as exhibited by IR spectra after irradiation of the materials at doses tested. Likewise, no significant changes were observed in gas permeability of plastics packaging materials after irradiation.
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Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials
Radiation Physics and Chemistry, 1999Co-Authors: Kyriakos A Riganakos, D.a.e. Ehlermann, W D Koller, B. Bauer, Michael G. KontominasAbstract:Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap Technique and identified by combined gas chromatography–mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. No significant changes were observed in the structure of polymer matrices as exhibited by IR spectra after irradiation of the materials at doses tested. Likewise, no significant changes were observed in O2, H2O and CO2 permeability values of plastic packaging materials after irradiation.
Janusz Pawliszyn - One of the best experts on this subject based on the ideXlab platform.
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needle trap extraction for gc analysis of formic and acetic acids in aqueous solution
Journal of Separation Science, 2012Co-Authors: Xinqing Lee, Daikuan Huang, Dawei Lou, Janusz PawliszynAbstract:Formic and acetic acids are ubiquitous in the environment, food, and most of the natural products. Extraction of the acids from aqueous solution is required for their isotope analysis by the gas chromatography-isotope ratio mass spectrometry. To this objective, we have previously developed a Purge-and-Trap Technique using the dynamic solid-phase microextraction technology, the NeedlEX. The extraction efficiency, however, remains unexamined. Here, we address this question using the flame ionization detector and isotope ratio mass spectrometer while comparing it with that of the CAR/PDMS fiber. The results show that the NeedlEX is applicable at a wide range of concentration through coordination of purge volume given the minimum amount 3.7 ng and 1.8 ng of formic and acetic, respectively, is extracted. The efficiency of NeedlEX was 6-7 times lower than the fiber at 1000 μg/mL depending on the analyte. It is, however, superior to the latter at 10 μg/mL or less owing to its lower detection limit. The extraction efficiency of both acids is equivalent in molar amount. This is, however, disguised by the different response of the flame ionization detector. The isotope ratio mass spectrometor overcomes this problem but is compromised by relatively large errors. These results are particularly useful for isotopic analysis of carboxylic acids.
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development of a syringe pump assisted dynamic headspace sampling Technique for needle trap device
Journal of Chromatography A, 2008Co-Authors: Vadoud H Niri, Janusz PawliszynAbstract:Abstract This paper describes a new approach that combines needle trap devices (NTDs) with a dynamic headspace sampling Technique (purge and trap) using a bidirectional syringe pump. The needle trap device is a 22-G stainless steel needle 3.5-in. long packed with divinylbenzene sorbent particles. The same sized needle, without packing, was used for purging purposes. We chose an aqueous mixture of benzene, toluene, ethylbenzene, and p -xylene (BTEX) and developed a sequential purge and trap (SPNT) method, in which sampling (trapping) and purging cycles were performed sequentially by the use of syringe pump with different distribution channels. In this Technique, a certain volume (1 mL) of headspace was sequentially sampled using the needle trap; afterwards, the same volume of air was purged into the solution at a high flow rate. The proposed Technique showed an effective extraction compared to the continuous purge and trap Technique, with a minimal dilution effect. Method evaluation was also performed by obtaining the calibration graphs for aqueous BTEX solutions in the concentration range of 1–250 ng/mL. The developed Technique was compared to the headspace solid-phase microextraction method for the analysis of aqueous BTEX samples. Detection limits as low as 1 ng/mL were obtained for BTEX by NTD-SPNT.
D.a.e. Ehlermann - One of the best experts on this subject based on the ideXlab platform.
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Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials
Developments in food science, 2007Co-Authors: Kyriakos A Riganakos, D.a.e. Ehlermann, W D Koller, B. Bauer, Michael G. KontominasAbstract:Abstract Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap Technique and identified by combined gas chromatography-mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds proportionally increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. No significant changes were observed in the structure of polymer matrices as exhibited by IR spectra after irradiation of the materials at doses tested. Likewise, no significant changes were observed in gas permeability of plastics packaging materials after irradiation.
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Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials
Radiation Physics and Chemistry, 1999Co-Authors: Kyriakos A Riganakos, D.a.e. Ehlermann, W D Koller, B. Bauer, Michael G. KontominasAbstract:Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap Technique and identified by combined gas chromatography–mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. No significant changes were observed in the structure of polymer matrices as exhibited by IR spectra after irradiation of the materials at doses tested. Likewise, no significant changes were observed in O2, H2O and CO2 permeability values of plastic packaging materials after irradiation.
W D Koller - One of the best experts on this subject based on the ideXlab platform.
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Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials
Developments in food science, 2007Co-Authors: Kyriakos A Riganakos, D.a.e. Ehlermann, W D Koller, B. Bauer, Michael G. KontominasAbstract:Abstract Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap Technique and identified by combined gas chromatography-mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds proportionally increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. No significant changes were observed in the structure of polymer matrices as exhibited by IR spectra after irradiation of the materials at doses tested. Likewise, no significant changes were observed in gas permeability of plastics packaging materials after irradiation.
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Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials
Radiation Physics and Chemistry, 1999Co-Authors: Kyriakos A Riganakos, D.a.e. Ehlermann, W D Koller, B. Bauer, Michael G. KontominasAbstract:Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap Technique and identified by combined gas chromatography–mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. No significant changes were observed in the structure of polymer matrices as exhibited by IR spectra after irradiation of the materials at doses tested. Likewise, no significant changes were observed in O2, H2O and CO2 permeability values of plastic packaging materials after irradiation.
