微波消解-电感耦合等离子体质谱法测定面料中的锗含量

电感耦合等离子体质谱法具有灵敏度高、速度快、线性范围宽等优点,可用于面料中微量元素的测定。通过微波消解法消解纺织面料,采用电感耦合等离子体质谱法(ICP-MS)测定纺织面料中的锗含量,建立了微波消解-电感耦合等离子体质谱法测定面料中锗元素含量的方法。研究结果表明,锗元素在0.2~40.0μg/L范围内线性关系良好(R2=0.999 9),方法的检出限为0.02 mg/kg,不同含量加标(0.02、0.04、0.08、0.16 mg/kg)回收率在82.6%~107.8%,相对标准偏差3.0%~9.3%(n=6)。该方法具有灵敏度高、精密度好、检出限低的优点,能够用于面料中锗元素含量的测定。     

电感耦合等离子体质谱法同时测定大枣中7种重金属及有害元素及健康风险评估

目的建立电感耦合等离子体质谱法测定大枣中7种重金属及有害元素含量的方法并开展健康风险评估。方法采用微波消解法进行样品前处理、电感耦合等离子体质谱法测定。健康风险评估模型计算风险评估模型(target hazard quotients, THQ)。结果各元素在相应范围内线性良好(r>0.999),仪器精密度良好(RSD<5%,n=6),各元素加样回收率为83.93%~104.95%。3个产地不同批次大枣中铜(Cu)、砷(As)、镉(Cd)、汞(Hg)、铅(Pb)重金属及有害元素含量较低,低于《中华人民共和国药典》2020年版中指导值;以THQ作为风险评估指标时,大枣所含重金属含量对人体健康无风险。结论 ICP-MS法灵敏、准确,可用于红枣中7种重金属含量的测定。     

枸杞中11种元素的快速质谱分析与质量控制

采用电感耦合等离子体质谱法测定枸杞中铅镉砷铬镍等11种有害重金属元素的含量。以HNO3-H2O2密闭高压消解法获取枸杞中的金属总量,以碰撞反应池技术/干扰方程消除实验中出现的多原子离子干扰,采用电感耦合等离子体质谱法测定其中的重金属元素含量,同时以大虾标准物质(GBW10050)作为过程监控样品。实验结果表明,标准物质的测定结果与证书标示值相符,相对标准偏差小于5%,方法快速、灵敏、准确度高,适用于枸杞中重金属元素的批量检测。     

电感耦合等离子体质谱法测定柳州螺蛳粉中12种元素

目的 建立电感耦合等离子体质谱法测定柳州螺蛳粉中12种元素含量的分析方法。方法 采用硝酸+双氧水进行微波消解,电感耦合等离子体质谱法进行测定,并对方法学进行考察。结果 各元素在相应的浓度范围内呈良好的线性关系,相关系数为0.9974～0.9999,检出限为0.0005～0.008mg/kg,精密度RSD为1.2%～4.0%,回收率为86.5%～97.0%。结论 本研究建立的方法准确、可靠、灵敏度高,适用于柳州螺蛳粉中12种元素测定。     

电感耦合等离子体质谱法测定预混矿物质中的碘

目的建立电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定预混料矿物质中碘元素。方法样品经5%氨水超声提取,通过电感耦合等离子体质谱仪,以103Rh作为在线内标,对样品溶液进行测定。结果在碘浓度为0～200μg/L的范围内,线性关系良好,线性方程为Y=8.173×10~(-4)X+1.991×10~(-4),相关系数r为0.9993。对预混料样品加入低、中、高3个梯度进行加标测定,回收率在88.6%～101.0%之间,相对标准偏差小于2.3%(n=3)。结论该方法准确、便捷、回收率良好,适用于不同预混料矿物质中碘含量的测定。     

电感耦合等离子体质谱法测定米酒中锰、铅、铜、铁的含量

采用电感耦合等离子体质谱 (ICP -MS)法测定米酒中锰、铅、铜、铁元素的含量 ,并与原子吸收法测定锰、铅、铜、铁作对比试验 ,提出电感耦合等离子体质谱法 (ICP -MS法 )具有灵敏度高 ,精密度好 ,线性范围宽等特点。方法检出限为 0 .0 0 6～ 0 .0 2 3mg/kg ;加标回收率为 89.8%～ 10 1.6 %之间 ;RSD为 0 .873%～ 6 .38%。     

电感耦合等离子体质谱法测定咸香香肠调料中钠元素含量

建立了电感耦合等离子体质谱法(ICP-MS)对咸香香肠调料中钠元素含量的测定方法。本法利用热的稀硝酸溶液提取样品中的钠元素,电感耦合等离子体质谱仪检测,内标法定量。本法标准溶液线性范围为1~10 ng/mL,适用于钠含量5%~50%的香肠调料中钠元素含量的测定,平均回收率为98.45%,仪器的重现性、稳定性较好。     

电感耦合等离子体质谱法测定玫瑰花花瓣及花酱中15种金属元素含量

目的建立电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定玫瑰花花瓣及花酱中15种金属元素含量的分析方法。方法样品经微波消解后,对仪器工作条件以及内标元素的选择进行优化,用标准模式及动能歧视消除(kinetic energy discrimination,KED)模式进行分析,采用电感耦合等离子体质谱法对15种金属元素的含量进行测定。结果各金属元素在各自的浓度范围内线性关系良好(r~20.999);检出限为0.020～5.633μg/L;精密度、稳定性、重复性的相对标准偏差(relative standard deviation,RSD)均小于4%;平均回收率达92.0%～131.2%,RSD为0.6%～3.5%。结论该方法操作简便、分析快速、灵敏度高、结果准确、适用于玫瑰花与它花酱中金属元素含量的测定。     

电感耦合等离子体质谱法同时测定茶叶中的铅、砷、铬、镉

电感耦合等离子体质谱法(ICP-MS)具有准确度高、检测速度快、检测灵敏度高的优点,用于测定茶叶中的铅(Pb)、砷(As)、铬(Cr)与镉(Cd)4种有害金属元素时,4种元素的检出限均可达到0.005 mg/kg,加标回收率均在96.1%～98.7%范围内,元素精密度均不超过3%。     

电感耦合等离子体质谱法测定云南市售大米中4种有益元素

目的建立石墨湿法消解-电感耦合等离子体质谱法同时测定云南大米中4种有益元素含量的方法。方法以产自云南省12个州市共90件大米为实验对象,采用石墨湿法消解对样品进行前处理,电感耦合等离子体质谱法进行测定,内标法定量分析云南大米中锰(Mn)、铁(Fe)、铜(Cu)、锌(Zn)4种有益元素的含量。结果云南大米中锰、铁、铜、锌4种金属元素在0~100μg/L质量浓度范围内呈现良好的线性关系,相关系数均大于0.999。通过加标回收实验分析锰、铁、铜、锌4种金属元素的加标回收率依次为93.61%~100.37%、88.32%~105.47%、99.91%~101.78%、94.14%~102.89%,相对标准偏差依次为3.37%、1.02%、0.16%、1.18%,4种金属检出率均为100%。结论石墨湿法消解-电感耦合等离子体质谱法精密度好、准确度高,可同时测定大米中多种金属,适用于云南大米中锰、铁、铜、锌含量的测定。     

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.     

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.     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.