离子色谱法测定茶叶中4种阴离子

为考察茶叶中F~-、Cl~-、NO_3~-、SO_4~(2-)这4种离子含量,称取0.500 0 g固体茶叶,高温灰化。采用IC6000型离子色谱,以流速0.7 mL/min的3.6 mmol/L碳酸钠溶液为淋洗液进行洗脱,外标法对茶叶中4种阴离子进行定量分析。结果表明,方法回归方程的线性相关系数在0.999 0～0.999 6之间, 4种阴离子检出限为0.5～1.5 mg/kg,加标量约为本底浓度的0.5, 1.0和1.5倍,加标回收率在95.0%～104.5%之间,测定值的相对标准偏差(n=3)为0.97%～1.35%。方法具有操作简便、检测干扰小、结果准确可靠的优点。     

离子色谱法测定饮用水中常见4种阴离子

目的建立离子色谱法测定水溶液样品中的F~-、Cl~-、NO_3~-和SO_4~(2-)的分析方法。方法用离子色谱法测定饮用水中阴离子的含量,使用电导检测器检测,淋洗液为15 mmol/L KOH,用Ion Pac AS19(250 mm×4 mm,7.9μm)阴离子分离柱、ASRS-300(4 mm)阴离子抑制器进行分离测定,一次进样25μL。结果 4种阴离子相关系数为r~20.99,回收率在96.5%～108%,相对标准偏差(relative standard deviation,RSD)(n=6)小于4%。结论该方法简便、快速、准确度高、前处理简单,适合检测饮用水中的阴离子。     

离子色谱法测定五大连池矿泉水中无机阴离子

为了研究五大连池矿泉水中无机阴离子含量和组成,采用离子色谱法测定五大连池矿泉水中的F~-、Cl~-、NO_2~-、NO_3~-和SO_4~(2-)五种阴离子的含量。建立能同时测量重碳酸矿泉水和偏硅酸矿泉水中5种阴离子的测试方法。该方法色谱峰分离效果好,标准曲线相关系数在0.999以上,方法检出限在0.011～0.025 mg/L之间,标准偏差在1.03%～3.92%之间(N=15),加标质量浓度在1～3 mg/L之间,加标回收率在97.70%～103.68%之间(N=15)。结果表明,五大连池矿泉水阴离子含量适中,测定的5种阴离子均符合GB 8537—2008的相关规定。     

离子色谱法测定昌都市江水中5种阴离子

建立了离子色谱法-电导检测器同时测定扎曲、昂曲与澜沧江水中F~-,Cl~-,Br~-,NO_3~-及SO_4~(2-)等5种阴离子。采用Dionex Ion Pac AS19分离柱和Ion Pac AG19保护柱,在16 min内完成阴离子分离和检测。分析条件:淋洗液为20 mmol/L KOH,流速为1.0 mL/min,柱温为30℃。阴离子的定性限和定量限分别为0.5~3.8μg/L和1.7~12.7μg/L,线性相关系数在0.999 0以上,氟离子、氯离子、溴离子、硝酸根和硫酸根回收率范围分别为97.1%~107.5%,91.3%~103.9%,97.4%~103.2%,94.8%~100.6%和93.8%~103.3%,相对标准偏差均小于3%(n=7)。该方法准确度好、精密度高、快速,适用于检测扎曲、昂曲与澜沧江水中5种阴离子含量。     

离子色谱法测定包装饮用水中10种阴离子

为建立快速准确地同时测定包装饮用水中1 0种阴离子(F~-、ClO_2~-、BrO_3~-、Cl~-、NO_2~-、ClO_3~-、Br~-、NO_3~-、PO_4~(3-)、SO_4~(2-))的离子色谱方法,选择瑞士万通Metrohm 883离子色谱仪,以Metrosep A Supp 1 Guard/4.6+Metrosep A Supp 5-250为分析柱,淋洗液为3.2 mmol/L碳酸钠+1.0 mmol/L碳酸氢钠,抑制器采用50 mmol/L硫酸溶液电解H~+再生液,流速为0.7mL/min,英蓝超滤在线样品前处理系统,进样体积为250μL,电导检测器温度30℃。通过实验分析该方法的线性、检出限、回收率和精密度,结果表明,标准曲线平均相关系数为r=0.999 4,各离子回收率为95.0~105.0%,相对标准偏差RSD均5%。     

离子色谱法测定饮用水中6种阴离子的研究

建立一种测定饮用水中6种阴离子的离子色谱分析方法.选用Dionex Ion Pac AS-19阴离子色谱柱,结合Dionex Ion Pac AG-19保护柱,Dionex ASRS 300抑制器,RFC-30淋洗液自动发生器,采用20mmol/L KOH淋洗液,流速为1.0mL/min.在一定的浓度范围内,各组分线性关系良好(r＞0.999),检出限1.4μ g/L～6.4μg/L,回收率范围:90.2％～106.6％.该方法简便、灵敏、准确,可以作为水中阴离子的检测方法.     

离子色谱法测定酒精和甲醇中的四种无机阴离子

建立了离子色谱测定酒精和甲醇中F~-、Cl~-、SO_4~(2-)、NO_3~-4种无机阴离子的方法。试样中加入适量氢氧化钠溶液,恒温水浴蒸至近干,用水定容至刻度。色谱柱采用AS15-HC阴离子色谱柱,流动相为40 mmol/L氢氧化钠溶液,流速1.0 m L/min。结果表明:4种阴离子呈良好线性关系(r=0.99902~0.99983),方法检出限分别为0.5、0.5、1.0、1.0 mg/kg,在低、中、高3个加标水平下的平均回收率为82%~110%,相对标准偏差为1.45%~4.64%(n=6)。该方法准确、简便、灵敏、通用、重现性好,可用于酒精、甲醇中4种阴离子的实际检测。     

固相萃取-离子色谱法测定茶叶中的阴离子

建立了用离子色谱同时测定茶叶中的F~-、Cl~-、NO_2~-、NO_3~-、SO_4~(2-)5种重要阴离子的分析方法。以Ionpac AS11为分离柱、AG11为保护柱、NaOH等浓度洗脱,以普洱绿茶为样品,考察了不同的回流时间,提取液体积,筛目大小对茶叶提取率的影响,其他3种茶叶作为推广。结果表明:该方法回归方程的线性相关系数在0.999 1~0.999 8之间,各组分的检出限在0.015mg/L~0.041 mg/L之间,RSD值5%,加标回收率在80.6%~113.7%之间。该方法具有快速、灵敏、准确的特点,用于实际茶叶样品中阴离子的分析,结果令人满意。     

液相色谱-串联质谱法测定饮用水中的卤氧化物

目的建立一种液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry,LC-MS/MS)同时检测饮用水中3种卤氧化物(高氯酸盐、氯酸盐及溴酸盐)的分析方法。方法水样直接经0.22μm水系滤膜过滤,采用100 mmol/L乙酸铵(A)和乙腈(B)作为流动相进行等度洗脱,经IC-Pak~(TM) Anion HR色谱柱分离,质谱(ESI-)采用多离子检测模式(MRM)对3种卤氧化物的定量离子和定性离子进行监测。结果本方法在6min内即完成3种目标化合物的分离分析。高氯酸盐及溴酸盐在0.5~50μg/L浓度范围内线性良好、氯酸盐在0.5~100μg/L浓度范围内线性良好(r≥0.999)。添加浓度为0.5、10.0、50.0μg/L,实验结果表明高氯酸盐、氯酸盐及溴酸盐的回收率可达84.8%~101.4%,相对标准偏差均小于10.0%(n=6)。高氯酸盐、氯酸盐及溴酸的检出限分别为0.1、0.2、0.2μg/L。结论该方法快速、准确、灵敏,适合测定饮用水中高氯酸盐、氯酸盐及溴酸盐的同时测定。     

毛细管区带电泳-间接紫外检测法测定婴儿配方奶粉中的胆碱

目的建立毛细管区带电泳-间接紫外检测法测定婴儿配方奶粉中胆碱含量的新方法。方法用5 mmol/L乙酸提取婴儿配方奶粉样品中的胆碱,涡旋混匀、9000 r/min离心,上清液经0.45μm醋酸纤维素滤膜过滤后进样。用未涂覆熔融石英毛细管75μm×70 cm(有效长度:60 cm)作为分离柱。以10 mmol/L磷酸二氢钠+20 mmol/L磷酸+7 mmol/L 4-甲基咪唑为分离缓冲体系。分离电压为28 k V,进样压力及时间为0.5 psi、10 s,检测波长为214 nm。结果胆碱的校正峰面积与质量浓度在8.7~86.8 mg/L范围内间线性关系良好,相关系数为0.9997、检出限为2.6 mg/L、定量限为8.7 mg/L,方法的日内和日间精密度分别为1.9%和3.9%(n=7)。3个质量浓度添加水平的平均加标回收率分别为98.8%、95.2%及97.6%,相应RSD分别为0.8%、0.9%及0.6%(n=5)。用本法分析了10件婴儿配方奶粉样品,均获满意结果。结论本方法简单、无需有机溶剂,适用于婴儿配方奶粉中胆碱的常规检测。     

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.     

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