首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到12条相似文献,搜索用时 0 毫秒
1.
The presence of mineral oil saturated hydrocarbons (MOSH) and aromatic hydrocarbons (MOAH) in food is a safety concern. Migration to food from recycled paper and board is a relevant source of MOSH and MOAH, and the potential of several technologies to reduce it was explored. These technologies were assessed for food safety (people), environment (planet) and economy (profit) in an integrated way, using a framework developed to compare the effect of the technologies with the current state of the art. Two mature technologies were evaluated (MB12 and flotation), two in development (supercritical CO2 and thermal treatment), and two as a concept (anionic trash catchers and functionalized clays). The use of mineral-oil-free inks for printing newspapers was also evaluated. It was concluded that, although it is desirable to apply mineral-oil-free inks, in the short-term reduction technologies have more impact. All technologies of which the effectiveness could be investigated (MB12, flotation, supercritical CO2 and thermal treatment) are able to reduce the potential migration of mineral oils by >70%, but none score optimally on all indicators. The MB12 technology shows the best overall performance and is ready for implementation, provided its patent will be available to more parties. Supercritical CO2 performs best on food safety, but environmental and economic performance has to be improved. The developed assessment framework yields a clear overview of the advantages and disadvantages of the technologies. Based on the assessment, recommendations are made to stakeholders, including the recycling industry, the ink and printing industry, the food industry and research institutes.  相似文献   

2.
The process of the transfer of a contaminant through a package made of a recycled film in good contact with a virgin film playing the role of a functional barrier is studied. The two films being made of the same polymer, the contaminant diffuses within the two layers of polymer with the same constant diffusivity. Convective transfer of the contaminant takes place through the surface of the functional layer in contact with the food, while the other external surface is impermeable to it. The effect of the coefficient of mass transfer at the packaging-food interface on the rate of transfer of the contaminant to the food is especially studied. Dimensionless numbers are used, making the results general.  相似文献   

3.
An analytical survey of 20 paper and board (P&B) materials intended for food use was carried out with the aim to identify chemicals with a potential to migrate into foods. Representative materials covering a range of uses (primary and secondary packaging and article for take away foods) were obtained from distributors. A screening approach was applied by means of solvent extraction with subsequent analysis by gas chromatography/mass spectrometry. A large number of analytes were detected, and a chemometric approach was used to explore the data. Principal component analysis was used to identify and select some compounds as markers for sample classification. In the corrugated and printed packaging, it is worth emphasizing the presence of residual solvents, probably coming from printing inks, as well as hydrocarbons and aromatic compounds, mainly toluene and plasticizers linked also to the recycled pulp content such as diisobutyl phthalate or diisopropylnaphthalenes, whereas in the plastic‐laminated samples, triacetin was identified as the prevailing compound. A literature search for safety data or legislative restrictions of the identified substances was performed. Additionally, the semi‐quantification of the compounds in the packaging allowed a worst case estimation of food contamination by means of the infinite total migration model; occasionally, migration estimations overcame the specific migration limits. The chosen analytical methods coupled with a chemometric approach proved to be an effective way to describe the data; it may be concluded that only the simultaneous consideration of several chemicals with a multivariate approach allowed the investigated packaging materials to be distinguished. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

4.
目的 以食品接触用纸/铝/塑复合包装为研究对象,结合应用非靶向高通量筛查技术和安全风险评价方法,全面研究这类多层复合包装在接触食品过程中的迁移风险。方法 采用顶空气相色谱-串联质谱、气相色谱-四极杆飞行时间质谱和液相色谱-四级杆飞行时间质谱全面筛查食品接触用纸/铝/塑复合包装在不同迁移条件下的挥发性、半挥发性和非挥发性迁移物质,基于商业数据库、实验室自建库及行业信息解析物质化学结构及可能来源,利用内标半定量迁移水平,结合国内外食品接触材料法规和安全风险评估方法进行符合性评价及风险评价。结果 20批纸/铝/塑复合食品包装在体积分数为4%的乙酸模拟物中未发现迁移风险,在体积分数为95%的乙醇模拟物中共计检出35种物质,可能源于溶剂、抗氧剂、爽滑剂、低聚物、抗氧剂氧化/降解产物等物质。其中,33种物质经法规评估及毒理学评估,显示风险较低;其余2类聚烯烃低聚物因结构难以确定、缺乏毒理学研究建议持续关注毒理学研究进展及国内外法律法规动态。结论 通过结合应用非靶向高通量筛查技术和安全风险评估方法研究表明,在通常的使用条件下,纸/铝/塑多层复合包装用于盛装果汁等水性食品时不存在安全风险,但接触高乙醇含量或油脂类食品时建议关注聚烯烃类低聚物的迁移安全性。  相似文献   

5.
Migrates from plastic food packaging were tested for oestrogen activity by yeast oestrogen screen and subsequently analysed by gas chromatography—mass spectrometry and high‐performance liquid chromatography—mass spectrometry to identify oestrogen‐active chemicals. Plastic samples were migrated according to EC 10/2011 with worst case scenarios being used. Food simulants consisted of either 10–95% ethanol or ultrapure water. Migrates were concentrated afterwards by solid phase extraction. Food contact material tested included polyethylene terephthalate, polypropylene, polyethylene, polystyrene and composite films. Oestrogenic activity ranging from 0.7 to 59 ng/l 17ß‐estradiol equivalents was detected in seven out of 42 samples tested. The highest activity was found in a composite film sample. All 11 polyethylene terephthalate samples tested negative for oestrogen activity. A number of chemicals with known or supposed oestrogen activity were identified in migrates of oestrogen‐active samples. These include butylated hydroxytoluene, 1,3‐diphenylpropane, 1,2‐diphenylcyclobutane and dibutyl phthalate. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

6.
分析了气相色谱-质谱联用法测定印制线路板中多溴联苯(PBBs)及多溴联苯醚(PBDEs)含量的不确定度来源,求出各不确定度分量,将不确定度分量合成给出实验结果不确定度。  相似文献   

7.
Benzophenone (BP) and its derivates are photoinitiators widely used in food packaging to cure inks or lacquers with ultraviolet light on cardboards and papers. Although there is no specific European legislation covering printing inks for food contact use, the European Food Safety Authority published recommendations of a limit of 0.6 mg/kg for the sum of BP and 4‐methylbenzophenone. In this study, a method has been devised to test migration levels of BP and BP derivates in foodstuffs. Eleven different paper or cardboard materials were analysed for their BP and derivative contents. The qualitative and quantitative analyses of BP and other 17 derivatives for the first time were performed by gas chromatography–mass spectrometry system. The method was evaluated by validation parameters such as linearity, repeatability, accuracy and precision values. According to results, maximum values by specific migration test (at 40°C for 10 days, using TENAX) were 10.83 mg/l for BP, 0.53 mg/l for 1‐hydrocyclohexylphenylketone, 0.47 mg/l for 4‐methylbenzophenone, 0.22 mg/l for 2,2‐dimethoxy‐2‐phenylacetophenone and 0.4 mg/l for methyl‐2‐benzoylbenzoate.  相似文献   

8.
Assessment of the optimal mixture is an important issue to obtain desired quality. This paper integrates grey relational analysis and an objective weighting technique into the Taguchi method to propose the weighted Grey-Taguchi method. This method can be employed to assess the optimal mixture with multiple responses. In the application of this method, water/cement ratio, volume ratio of recycled coarse aggregate, replacement by river sand, content of crushed brick, and cleanliness of aggregate are selected as control factors with responses of slump, slump-flow, resistivity (7-day, 14-day, 28-day), ultrasonic pulse velocity (7-day, 14-day, 28-day), and compressive strength (7-day, 14-day, 28-day) to assess the optimal mixture of recycled aggregate concrete. Results demonstrate and verify that the optimal mixture has a water/cement ratio of 0.5, a volume fraction of recycled coarse aggregate of 42.0%, 100% replacement of river sand, 0% crushed brick, and water-washed aggregates.  相似文献   

9.
A pilot study on errors of commission (EOCs) was performed for a Swiss nuclear power plant, with the goals of (a) evaluating PSI's Commission Errors Search and Assessment (CESA) method for identifying potential EOC situations, and (b) obtaining an estimate of the potential risk significance of the analyzed EOCs. The EOC search and screening process of the method proceeds from a given action to scenarios in which the action is inappropriate. A catalog of key actions required in the responses to the plant events is first compiled. This catalog is then used in a systematic search of context-action combinations, to obtain a set of situations with EOC opportunities to be examined in detail. The results show that the CESA identification process is feasible and effective: it is able to identify plausible situations in which EOCs may occur. A preliminary quantification of four of these has been performed; the analyses so far show that the situations identified in the pilot study deserve careful consideration. Although the identification approach in CESA covers a subset of EOC types, the demonstration of the CESA method in the pilot study and the resulting identification of EOC cases is encouraging in terms of progress on the issue of EOCs.  相似文献   

10.
粘胶活性碳纤维预浸剂的热分解作用及效能评选   总被引:1,自引:0,他引:1  
用热失重分析方法研究了磷酸铵盐、磷酸、硫酸铵对粘胶纤维的热分解促进作用.空气的存在有利于磷酸氢二铵对粘胶的分解反应,但对其余几种的影响不大.本文提出用峰高/半高宽之比表征热分解峰的形态.该值越低,即热分解峰越平坦,表明反应越缓和,则越有利于提高粘胶纤维的碳化活化得率.实验结果证实了这一观点.磷酸氢二铵/粘胶的热分解峰最平坦,作用效果最好;磷酸二氢铵和磷酸相当,磷酸铵次之,硫酸铵作用时比表面积很低.未预浸处理的粘胶热分解最激烈,产品得率和比表面积也最低.  相似文献   

11.
A mathematical model of a method of measuring the thermal properties of new regenerative products is developed. The construction of a measuring instrument is proposed. Experimental data on the thermal conductivity and volume heat capacity of regenerative products in a matrix are obtained. Translated from Izmeritel’naya Tekhnika, No. 5, pp. 49–53, May, 2009.  相似文献   

12.
Nuclear-based explosive detection methods can detect explosives by identifying their elemental components, especially nitrogen. Thermal neutron capture reactions have been used for detecting prompt gamma 10.8 MeV following radioactive neutron capture by 14N nuclei. We aimed to study the feasibility of using field-portable prompt gamma neutron activation analysis (PGNAA) along with improved nuclear equipment to detect and identify explosives, illicit substances or landmines. A 252Cf radio-isotopic source was embedded in a cylinder made of high-density polyethylene (HDPE) and the cylinder was then placed in another cylindrical container filled with water. Measurements were performed on high nitrogen content compounds such as melamine (C3H6N6). Melamine powder in a HDPE bottle was placed underneath the vessel containing water and the neutron source. Gamma rays were detected using two NaI(Tl) crystals. The results were simulated with MCNP4c code calculations. The theoretical calculations and experimental measurements were in good agreement indicating that this method can be used for detection of explosives and illicit drugs.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号