气相色谱法测定白酒中氰化物的不确定度评定

目的评定气相色谱法测定白酒中氰化物的不确定度。方法分析气相色谱法测定白酒中氰化物的全过程,确认不确定度的来源和大小,合成不确定度,计算扩展不确定度并报出结果。结果白酒中氰化物的含量为13.8 mg/L,扩展不确定度为1.0 mg/L(P=95%, k=2)。结论通过对不确定度的来源分析及各分量的量化评定,回收率与标准曲线拟合对不确定度的影响较大,标准溶液、样品制备和测量重复性对不确定度的影响较小。     

高效液相色谱法测定鱼油软胶囊中维生素D3含量的不确定度评定

目的评定高效液相色谱法(high performance liquid chromatography,HPLC)测定鱼油软胶囊中维生素D_3含量的不确定度。方法依据国家计量技术规范JJF 1059.1-2012《测量不确定度评定与表示》对维生素D_3测定中的不确定度来源进行分析。通过建立数学模型量化不确定度分量,计算合成不确定度和扩展不确定度。结果本方法的不确定度主要来源于标准物质的含量、标准曲线的配制和标准曲线的拟合。当样品中维生素D_3的含量为2.08μg/kg,扩展不确定度为0.20μg/kg,维生素D_3含量表示为(2.08±0.20)μg/kg(k=2)。结论该评定方法可用于高效液相色谱法对鱼油软胶囊中维生素D_3的不确定分析。     

高效液相色谱-串联质谱法测定牛奶中3种磺胺类药物残留不确定度的评定

目的采用高效液相色谱-串联质谱法对牛奶中磺胺吡啶、磺胺噻唑和磺胺甲基异恶唑残留的不确定度进行评估。方法建立测定牛奶中磺胺吡啶、磺胺噻唑和磺胺甲基异恶唑含量不确定度的数学模型,确定不确定度来源并对其评定。结果当牛奶中磺胺吡啶含量为5.09μg/kg时,其扩展不确定度为0.62μg/kg(k=2);当牛奶中磺胺噻唑含量为8.62μg/kg时,其扩展不确定度为0.71μg/kg(k=2);当牛奶中磺胺甲基异恶唑含量为10.15μg/kg时,其扩展不确定度为0.81μg/kg(k=2)。其中,测量重复性和标准曲线对不确定度的影响最大。结论影响检测结果不确定度的主要因素为样品测量的重复性、标准曲线拟合和样品的前处理过程。     

酶联免疫吸附法测定花生油中黄曲霉毒素B1 不确定度的评定

目的对采用ELISA方法测定花生油中黄曲霉毒素B1含量的不确定度进行分析,找出影响不确定度的因素,为评价其测定方法和检测结果的可靠性提供依据。方法根据JJF 1059.1-2012《测量不确定度评定与表示》的规定,对测定过程中标准曲线拟合、重复测量、样品的稀释、样品的称量、回收率等引入的不确定度分量进行评定。结果测定结果合成不确定度为0.45μg/kg,扩展不确定度为0.90μg/kg,花生油中黄曲霉毒素B1含量测定结果为(16.54±0.90)μg/kg(k=2)。结论测定结果不确定度主要由标准曲线拟合所引入,所建立的不确定度评定方法可用于ELISA方法测定花生油中黄曲霉毒素B1含量结果的判断。     

微波消解-石墨炉原子吸收法测定水产制品中铬含量的不确定度评定

目的评定水产制品中铬含量测定的不确定度,为食品检验实验室提供更规范的不确定度评定方法。方法以烤鳕鱼片为例,参照GB 5009.123-2014《食品安全国家标准食品中铬的测定》用微波消解-石墨炉原子吸收光谱法测定食品中铬含量,对实验过程中引入的不确定度各分量进行分析,并计算合成标准不确定度及扩展不确定度。结果对评定结果产生影响的主要因子是标准溶液配制、标准曲线拟合和样品重复性测量过程,其中样品的重复性测量引入的不确定度对最终不确定度影响最大。分析得该样品中铬含量为419.60μg/kg,相对合成不确定度为10.526μg/kg,扩展不确定度为21.05μg/kg(k=2),最后结果表示(419.60±21.05)mg/kg(k=2,95%置信水平)。结论通过不确定度的评定,查找测量过程中可能存在的问题以规范操作,降低引入的不确定度,使检测结果更可靠。     

鸡肉中强力霉素残留测定不确定度评定

目的对液相色谱-质谱/质谱法测定鸡肉中强力霉素残留的不确定度进行评定,找出影响检测结果准确性的关键因素,从而提高检测结果准确性。方法按照GB/T 21317-2007《动物源性食品中四环素类兽药残留量检测方法液相色谱-质谱/质谱法与高效液相色谱法》对鸡肉中强力霉素残留量进行测定。通过建立数学模型,对影响测量结果的不确定度来源如标准物质的纯度、标准物质的称量、标准曲线的配制、样品的称量、样品的制备、标准曲线的拟合、样品测量重复性等因素进行分析和评定。结果鸡肉中强力霉素残留量为123.8μg/kg,扩展不确定度为8.9μg/kg,测定结果表示为:X=(123.8±8.9)μg/kg(k=2)。结论样品测量重复性和标准曲线绘制是本次测定测量不确定度的主要来源,在检测过程中应加以控制。     

碳酸饮料中山梨酸含量检测的不确定度评定

依据CNAS-GL05:2011《测量不确定度要求的实施指南》,对高效液相色谱法测定碳酸饮料中山梨酸的不确定度进行分析评定。测定过程中产生的不确定度主要来源于样品重复平行测量和标准物质纯度。分析结果表明,碳酸饮料中山梨酸的含量为0.1298g/kg,其扩展不确定度为0.0011g/kg(k=2)。     

微生物法测定婴幼儿乳粉中维生素B12含量的不确定度评定

目的建立微生物法测定婴幼儿乳粉中维生素B₁₂含量的不确定评定方法。方法依据JJF1059.1—2012《测量不确定度评定与表示》及GB 5413.14—2010《食品安全国家标准婴幼儿食品和乳品中维生素B₁₂的测定》分析微生物法测定婴幼儿乳粉中维生素B₁₂含量过程中产生的各测量不确定度分量,计算测量结果的合成标准不确定度和扩展不确定度。结果当样品中维生素B₁₂含量为3.97μg/100 g时,其扩展不确定度为0.53μg/100 g(k=2)。结论标准溶液配制和标准曲线拟合计算待测溶液含量产生的不确定度对检测结果影响较大。     

顶空-气相色谱法测定饮用水中三氯乙醛的不确定度评定

目的分析顶空-气相色谱法测定饮用水中三氯乙醛的不确定度。方法分析标准溶液的配制、样品测定重复性和拟合标准曲线等影响测量结果的不确定度分量,并计算合成不确定度和扩展不确定度。结果当水中三氯乙醛的测量结果为3.27μg/L,取包含因子k=2(置信水平约95%)时,扩展不确定度U=0.36μg/L。结论顶空-气相色谱法测定饮用水的不确定分量中影响最大的是配制标准溶液过程引入的不确定度,标准曲线拟合和样品测量重复性次之。     

高效液相色谱-串联质谱法测定甘草中赭曲霉毒素A的不确定度评定

目的评定高效液相色谱-串联质谱法(highperformanceliquidchromatography-tandemmass spectrometry,HPLC-MS/MS)测定甘草中赭曲霉毒素A(ochratoxinA,OTA)的不确定度。方法采用HPLC-MS/MS法,以~(13)C-稳定同位素标记的OTA为内标,测定甘草中OTA含量;建立数学模型,对测量重复性、标准曲线、样品前处理等不确定度来源进行分析和评定,得出合成标准不确定度和扩展不确定度。结果当甘草中OTA的含量为7.59μg/kg时,其扩展不确定度为0.50μg/kg(k=2)。结论该方法测定甘草中OTA含量的不确定度总体较小,测量不确定度的主要来源为标准曲线拟合,其次为测量重复性和标准曲线溶液配制,需要在实际操作过程中进行注意。     

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.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the