Z比分数-模糊AHP评价模型在卷烟成品实验室检测能力评价中的应用

为解决Z比分数法只能对卷烟成品实验室单个指标进行分析评价问题,将Z比分数、层次分析法(Analytic Hierarchy Process)与模糊综合评价法相结合,建立了Z比分数-模糊AHP评价模型。评价分为8个步骤:构建卷烟成品实验室评价指标体系,利用AHP确定各指标权重,将实验室每个样品的指标检测值转化为Z比分数(Z,ZB,ZW),利用模糊评价方法建立评语集和对应的分数集,把每个指标各样品Z比分数在评语集各等级所占比例作为隶属度,形成模糊判断矩阵,最终得到实验室物测、烟气以及综合检测能力评价得分及排序。以10个实验室为例验证了该模型的综合评价能力。结果表明,该综合评估方法适用于多样品和多指标的实验室比对综合能力评价,可以整体评价实验室物测、烟气和综合检测能力,并可分析查找存在问题的指标,为卷烟成品实验室的优化改进及提升检测能力水平提供了支持。      

2011年省级疾控中心食品中金属污染物质控考核结果分析

目的确保食品中金属污染物检测数据的准确性、可靠性和可比性。方法组织全国31个省级和新疆生产建设兵团的疾病预防控制中心对下发的豆粉或奶粉基质的质控考核样品进行镉和汞的含量测定,并运用国际上通用的"Z比分数"统计法和与FAPAS参考值比较两种方法对镉、汞的检测结果进行分析和评价。结果 31个实验室按时提交检测结果,镉的检测结果回收率为93.8%,合格率为90.6%;汞的检测结果回收率为96.8%,合格率为93.8%;两种元素的检测结果均合格的实验室占90.6%。结论目前全国省级疾病预防控制中心对食品中金属污染物的总体检测水平较高,但个别实验室的检测水平有待提高。     

2009年-2014年食品检验机构实验室能力验证

<正>目的:提高检测实验室质量监控能力,确保实验数据准确,更好地为食品安全监管工作提供技术支持。方法:根据组织方评价方法,对能力验证的结果按Z比分数和回收率方法进行判定,进而对结果进行归纳分析,对能力验证中不满意项目进行原因分析。结果:2009-2014年间本实验室共参加能力验证31次,考核项目数累计达128项次,满意率为96.9%。结论:能力验证是一种有效的实验室监控方     

饮料中日落黄盲样考核结果分析与评价

目的组织饮料中日落黄盲样考核活动,评价各食品实验室检测日落黄的能力与水平。方法设计2个浓度水平的日落黄盲样考核样品,并对样品进行均匀性与稳定性研究,获得各参加实验室检测结果,对结果进行稳健统计分析,通过Z比分数评价实验室的检测能力,并对结果进行分析。结果共有41家实验室参加了本次盲样考核,其中结果满意为33家,满意率为80.5%,结果可疑为3家,可疑率为7.3%,不满意结果为5家,不满意率为12.2%。结论参加本次盲样活动的实验室,多数实验室的检测能力评价为满意,表明各实验室具有饮料中日落黄的检测能力。但仍有部分实验室评价结果不满意,应分析原因并进一步提高实验室的检测能力水平。     

化妆品中二苯酮-3检测能力验证研究

目的评价实验室检测化妆品中二苯酮-3的技术能力和水平。方法实施能力验证计划,制备2个浓度水平的参考样品,经均匀性检验和稳定性检验符合考核样品要求,样品随机发放给111家单位实验室,并收集检测数据。对反馈结果开展稳健统计分析,用Z比分数进行实验室检测能力的评价。结果制备的样品均匀稳定,满足能力验证的计划要求。111家单位的总体满意率为94.6%。结论多数参加实验室检测能力评价为满意,检测结果离群的实验室应查找自身原因并加以修正。     

保健食品中格列本脲含量测定的能力验证研究

目的设计组织保健食品中格列本脲含量测定能力验证项目,评价实验室检测保健食品中格列本脲的技术能力和水平。方法对考核样品通过实施能力验证计划,来自27个省(自治区)、直辖市80家实验室的测定结果进行稳健统计分析,通过稳健Z比分数评价实验室检测能力。结果考核样品中的格列本脲在P0.05显著水平时是均匀的,且在整个计划周期内稳定,满足能力验证的要求。在80家参加实验室中,满意结果数为68家,满意率为85.0%;可疑结果数为6家,可疑率为7.5%;不满意结果数为6家,不满意率为7.5%。结论多数参加的实验室检测能力结果满意,表明保健食品中格列本脲检测水平总体良好。     

食品多元素检测质控图及国际比对结果在质量控制中的应用

目的通过分析本实验室根据标准参考物测定结果绘制的质控图和2013年10月参加食品中多种微量元素含量测定的国际实验室间比对考核结果,探讨质控图及国际比对考核在实验室质量控制中的应用。方法以Z比分数法评价由国际原子能机构组织的食品中多种微量元素含量测定的国际比对结果,分析食品样品中多种微量元素的测定情况。结果绝大多数元素的考核结果|Z|1,结果优秀。结论质控图和国际比对实验研究是分析实验室质量控制的有效方法,应鼓励有条件的实验室更多地参与国际比对考核,以提高其检测能力及测定结果的可靠性。     

肉糜中苯甲酸、山梨酸测定能力验证研究

目的评价检验机构对测定肉糜中苯甲酸、山梨酸的检测能力。方法对参加能力验证的88家实验室对苯甲酸和山梨酸的测定结果进行稳健统计分析,以Z比分数评价实验室检测能力。结果 88家实验室反馈了实验结果,满意率为77.3%。结论多数参加实验室对苯甲酸和山梨酸的检测结果达到了满意标准,得到不满意结果的实验室应查找自身原因并加以修正。     

食品多元素检测质控图及国际比对结果在 质量控制中的应用

摘要：目的 通过分析本实验室根据标准参考物测定结果绘制的质控图和2013年10月参加食品中多种微量元素含量测定的国际实验室间比对考核结果,探讨质控图及国际比对考核在实验室质量控制中的应用。方法 以Z比分数法评价由国际原子能机构组织的食品中多种微量元素含量测定的国际比对结果,分析食品样品中多种微量元素的测定情况。结果 绝大多数元素的考核结果 <1,结果优秀。结论 质控图和国际比对实验研究是分析实验室质量控制的有效方法,应鼓励有条件的实验室更多地参与国际比对考核,提高检测能力及测定结果的可靠性。     

稳健统计技术在酱油氨基酸态氮能力比对数据分析中的应用

利用稳健统计技术结合图示方法分析了酱油氨基酸态氮的能力比对数据;通过计算实验室间Z比分数和实验室内Z比分数,评估了实验室的结果并分析出实验室误差种类;结合实验过程,探讨了误差的主要来源,为改进实验室质量提供了依据。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

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-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

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.     

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.