包装饮用水中铜绿假单胞菌定性检验盲样考核的结果与分析

作为包装饮用水中铜绿假单胞菌检验资质的国家食品安全抽检监测承检机构,本实验室参加2016年食药总局食品安全抽检监测承检机构铜绿假单胞菌定性检验盲样考核。按照盲样考核作业指导书和《GB/T 8538-2008饮用天然矿泉水检验方法》的要求检验,并结合全自动微生物生化鉴定系统(VITEK 2)对分离出的可疑菌落鉴定。结果显示,样品1559、1562、1565、1580、1582检出铜绿假单胞菌,1546、1573、1574、1579、1584未检出铜绿假单胞菌。     

食品中单增李斯特菌检出的能力验证

能力验证是利用实验室间比对来判定实验室或检查机构能力的活动,能够有效评价参加实验室或检测机构的检测能力水平,也是实验室或检测机构进行自查和外部质量控制的一种重要方式~([1])。本文通过探讨食品中单核细胞增生李斯特氏菌(以下简称单增李斯特氏菌)检出能力验证的过程,为今后实验室致病性微生物的检出能力提供参考依据。方法:依据食品安全国家标准《食品微生物学检验食品中单核细胞增生李斯特氏菌检验》(GB 4789.30-2016)。结果:两个考核盲样结果均为检出。结论:本次能力验证结果经考核组织机构反馈为"首次满意"。     

茶叶中联苯菊酯、毒死蜱的测定能力验证结果与分析

目的通过参加能力验证实验,提高实验室农药残留检测的能力。方法优先选择本实验室常用方法,依据NY/T 761-2008、GB/T 23204-2008、GB 23200.13-2016方法,对样品进行相应的提取净化处理,随后根据相应的仪器进行定性定量检测分析,使用仪器比对、方法比对、人员比对、加标回收、质控样品作为质控方法。结果本次能力验证以NY/T761-2008报出检验结果。样品编号为18-U804检测结果为联苯菊酯:0.214 mg/kg, Z比分数为?0.4,毒死蜱为未检出;样品编号为18-Y023检测结果为联苯菊酯为0.582 mg/kg, Z比分数为?0.3,毒死蜱为0.364 mg/kg, Z比分数为?0.6,组织机构判定结果为满意。结论本次能力验证结果为满意,说明本实验室对农药残留的检测能力较好。     

米粉中γ-六六六农药残留盲样考核的结果分析和整改措施

目的分析米粉中γ-六六六农药残留盲样考核结果,讨论出现不满意结果的原因并提出相应的整改意见。方法按照GB/T 5009.19-2008盲样考核样品中的γ-六六六农药残留量进行分析,从人员、仪器、检测方法、环境、测试过程及物料等几个方面进行出现不满意结果的原因分析,制订相应的整改及预防措施,并在实施整改后参加测量审核。结果标准物质购买不规范以及没有正确评定标准物质的质量是此次盲样考核取得不满意结果的重要原因。通过整改后,参加测量审核,计算实验结果平均值为0.20 mg/kg,结果满意。结论本研究分析体现盲样考核的价值,得出本实验室需加强对实验室标准物质采购及验收的管理,提高实验室的质量管理水平。     

混合质控菌种盲样的鉴定分析

本文的目的是通过盲样考核提升实验室微生物检测能力和质量管理水平,依据食品卫生微生物学检验标准GB 4789及CMA评审专家提供的《致病菌鉴定作业指导书》进行检验。结果表明,盲样样品中检出鼠伤寒沙门氏菌(1,4,[5],12:i:1,2)和金黄色葡萄球菌,本次混合菌种鉴定项目取得了满意的实验结果。通过参加实验室盲样考核,检验人员提高了自身检测水平,增加了检测结果的可靠性。     

能力验证中单增李斯特菌的分离与鉴定

摘要: [目的] 通过参加CNAS比对能力验证计划,提高实验室检测校准能力。[方法] 依据GB 4789.30-2016《食品微生物学检验单增李斯特菌检验》基础方法和生化分子学方法相结合，对盲样进行定性检测。[结果] 2个盲样LMO（ZJ）-191和LMO（ZJ）-134分别为检出和未检出单增李斯特菌，检测结果为均通过。[结论] 本次采用多种组合实验方法，更加准确了解到单增李斯特氏菌的各项特征，综合提升了检测准确度和效率。     

2009—2014年辽宁省食源性致病菌盲样考核结果分析

通过分析辽宁省疾控中心及辽宁省食品检验检测院微生物实验室2009—2014年间参与的生物盲样考核结果,总结得出盲样考核的检验流程和关键点。方法 按照国家标准GB 4789—2010《食品安全国家标准 食品微生物学检验》对本实验室5年来参与的各级生物盲样进行检测分析。结果 8次考核所涉及的13个项目的考核结果均为优秀或满意。结论 生物盲样考核应该关注检验流程和关键点,参加盲样考核有助于提升实验室工作能力,确保日常检测结果的准确可靠。     

婴幼儿配方乳粉中维生素PP含量测定盲样考核研究

目的评价国家食品安全抽检监测承检机构实验室测定婴幼儿配方乳粉中维生素PP的技术能力和水平,分析存在的问题,以期提高其检验水平。方法具体实施婴幼儿配方乳粉中维生素PP含量测定盲样考核项目。制备2个浓度水平的考核样品,经均匀性检验和稳定性检验符合盲样考核要求,样品随机发放给23家单位实验室,其中1个样品作为考核样品进行结果统计分析,另一个样品作为干扰样。对参加该计划的23家单位的实验室测定结果进行稳健统计分析,用z比分数评价实验室检测能力。结果制备的样品均匀性符合要求且在整个计划周期内保持稳定,满足盲样考核要求。参加实验室上报的数据经分析,z比分数绝对值均小于2。结论 23家参加此次盲样考核项目的实验室评价均为满意,本项目检测水平总体良好。     

农产品豇豆中农药残留的检测能力验证结果分析

目的：通过参加河南省农业农村厅组织的2022年农产品质量安全(农产品中农药残留)检测能力验证工作,了解验证并提高本检测机构实验室对农产品中农药残留测定的能力水平。方法：依据作业指导书,参考GB 23200.113—2018中农药残留检测的基本操作,采用气相色谱-串联质谱法对收到的豇豆盲样进行检测,外标法定量。结果：样品A147中检出甲基对硫磷含量为0.047 8 mg·kg^-1,腐霉利含量为0.244 0 mg·kg^-1,联苯菊酯含量为0.046 2 mg·kg^-1;样品A153中氧乐果含量为0.035 0 mg·kg^-1,毒死蜱含量为0.043 5 mg·kg^-1;样品A165中乙酰甲胺磷含量为0.125 0 mg·kg^-1,甲胺磷含量为0.051 7 mg·kg^-1。结论：本次实验室的农药残留能力验证结果为满意。     

食品中微生物检测能力验证结果与分析

目的提高实验室检验人员微生物检测能力和水平,增强实验室竞争力。方法实验室参加中国检验检疫科学研究院测试评价中心组织的食品中单核细胞增生李斯特氏菌、副溶血性弧菌2项检验能力验证。按照盲样作业指导书的要求对样品进行前处理后,依据GB4789.30-2016《食品安全国家标准食品微生物学检验单核细胞增生李斯特氏菌检验》和GB 4789.7-2013《食品安全国家标准食品微生物学检验副溶血性弧菌检验》进行定性检测。结果样品17-P842鉴定出单核细胞增生李斯特氏菌,样品18-E886鉴定出副溶血性弧菌。结论本次能力验证结果满意,为今后实验室检测实际样品提供参考经验。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.