电感耦合等离子体质谱法测定食品中 二氧化钛的含量

目的优化电感耦合等离子质谱法测定二氧化钛的含量。方法样品前处理先通过硫酸湿法消解,放冷后再用加入30%过氧化氢继续消解,用电感耦合等离子质谱法测定二氧化钛中钛含量,根据质量分数计算出二氧化钛含量。结果通过比较微波消解、湿法消解、干灰化法消解和压力消解4种前处理方式,采用硫酸-双氧水的消解体系进行湿法消解。钛在0~50μg/mL范围内线性关系良好,相关系数为1.0000。在50、75和100 g/100mL 3个加标浓度下,样品的平均回收率为101.26%,平均相对标准偏差为2.8%。结论该方法简便、快捷,有较高的灵敏度、准确度、精密度,适合食品中二氧化钛含量的测定。     

电感耦合等离子体-质谱法检测城郊种植土壤中的铅、锰、镉、锡重金属残留量

目的:本实验建立利用电感耦合等离子体-质谱法检测城郊种植土壤中的铅、锰、镉、锡重金属残留量的分析方法。方法:取城郊土壤样品,研细,过筛,称取0.3 g试样,置聚四氟乙烯消解罐中,加1.0 mL水润湿,再分别加入浓硝酸6.0 mL、盐酸3.0 mL和2.0 m L氢氟酸,置微波消解仪中进行消解,赶酸后,将消解液转移至50 mL容量瓶中,加5%硝酸溶液定容至刻度,用ICP-MS仪、内标法定量检测。结果:铅、锰、镉、锡在浓度0.02～5.0μg/L范围具有良好的线性关系,R20.995;4种元素检测限依次为0.011、0.013、0.020和0.012μg/kg,重复性RSD依次为3.27%、2.61%、3.39%和4.11%,加标回收率范围均在80.0～120.0%之间。结论:方法不仅快速、简单,还具有重复性好、准确度高等优点,适用于土壤中重金属检测的研究。     

微波消化面粉的关键步骤

微波消化法是消化面粉样品的较好方法之一。本文从取样量、样品的预处理、溶剂的选择、微波加热方式及加热时间、冷却方法等几个环节对面粉样品在微波消化过程中应注意的一些问题进行了探讨，总结出微波消化面粉样品时适宜的条件和操作方法：准确称取1．0g样品于消解罐内，加1mL去离子水将样品充分润湿，然后加入10mL硝酸和2mL过氧化氢，按250W（3min）→0W（5min）→250w（5min）→400W（5min）→600W（5min）的消解程序执行样品消化，消解程序执行完毕约5min后取出消解罐，在通风橱中通风冷却25min。     

ICP-MS检测食品塑料包装迁移的纳米二氧化钛

将填充纳米二氧化钛的食品塑料包装浸泡于4%乙酸溶液中于50℃浸泡10 d,浸泡液蒸干后经硫酸和硫酸铵湿法消解定容,电感耦合等离子体质谱(ICP-MS)测定消解液中钛元素的含量,继而计算求得浸泡液中二氧化钛含量。通过实验得出最佳消解体系为4 mL硫酸+1.6g硫酸铵,方法检出限为0.15μg/dm~2,回收率为86%~95%,方法准确、快速、简便。     

蒽酮-硫酸比色法测定南瓜籽多糖含量

采用蒽酮-硫酸法测定南瓜籽多糖含量并对其测定条件进行研究。结果表明最佳条件为:蒽酮浓度2.0 mg/m L,体积分数80%的硫酸,样品溶液与蒽酮-硫酸试剂加入量的体积比为1∶4,加热时间15 min,冷却后放置10 min、625 nm比色。平均加标回收率为97.3%,RSD 3.98%。测得样品中多糖含量为18.14%。结果表明,该方法适用于南瓜籽多糖含量的测定。     

高效液相色谱-高分辨质谱法测定奶粉及保健品食品中的左旋肉碱

目的建立高效液相色谱-高分辨质谱法测定奶粉及保健食品中左旋肉碱的含量。方法奶粉及保健食品样品经适量40℃水溶解后,加乙酸锌沉淀蛋白,待样品冷却至室温后用水定容至50mL,并超声提取30 min。在4℃条件下,待测溶液经8000 r/min的速度离心3 min,取上清液过0.45μm水相滤膜。经质谱正离子模式测定,同位素内标法定量。结果左旋肉碱0.1～4.0μg/mL范围内呈良好线性关系,相关系数为1.0000,方法检出限为0.1μg/kg,定量限为0.2μg/kg。加标回收率为98%～110%,相对标准偏差为0.2%～0.5%。对奶粉质控样品进行测定,结果与证书结果一致。结论该法前处理简单、测定快速、准确度高,灵敏度好,适用于奶粉及保健食品中左旋肉碱的快速分析检测。     

用于印染废水脱色的稻壳吸附剂的研制

为提高稻壳的利用价值,以稻壳为原料研制对印染废水有强吸附作用的吸附剂。试验表明,用硫酸活化稻壳,用于吸附染料,最适的条件为:硫酸配成7.0%(w/v)的水溶液,每100g稻壳用硫酸溶液30mL,搅拌均匀,在130℃下活化50min,稻壳活化后对0.10mg/mL次甲基蓝溶液的吸附率为42.9%。经硫酸活化的稻壳再以每100g加10%(w/v)的双氧水30mL氧化活化,搅拌均匀,在180℃下活化50min,活化所得稻壳吸附剂对0.10mg/mL次甲基蓝水溶液的吸附率可以提高至84.1%。     

微波消解-固相萃取-气相色谱-质谱联用法测定泡沫快餐盒中的双酚A

目的 建立一种泡沫餐盒中双酚A的微波消解-固相萃取-气相色谱-质谱联用分析法.方法 取0.2g泡沫餐盒,置入50 ml微波消解罐中,加入20 ml纯净水,进行微波消解,消解液经固相萃取小柱(C18,500 mg,6 ml)富集净化,氮气50 ℃吹干后加入900 μl甲苯和100 μl衍生化试剂BSTFA-TMCS(99∶1,V/V),于恒温干燥箱中85℃,衍生化反应30 min,经0.45μm滤膜过滤后上机.结果 本方法的线性范围为0.305 ～ 3.05 mg/L,r2=0.991;方法的加标回收率范围为90％ ～101％,RSD为2.6％ ～5.0％.当取样量为0.2g时,双酚A的最低检出限为15 μg/kg.结论 该方法前处理过程简便,定性、定量准确,完全能用于泡沫餐盒的双酚A检测.     

微波在纺织品纤维含量检测中的应用

本研究将微波引入纺织品纤维含量化学法检测中,将纺织纤维在75%硫酸溶液中,经过微波加热至50℃恒温完成消解,剩余物在微波条件下干燥。研究表明,微波加热方式可以明显提升纺织品纤维含量化学法检测效率,样品在20 min内完成消解,35 min内完全干燥,减少约80%化学试剂的使用,试验结果与标准测试结果的偏差<1.2%,试验环境得到极大改善。     

微波消解-原子荧光法测定牛乳中硒含量的优化实验

本文采用微波消解-原子荧光法,通过对比不同的消解参数、赶酸温度、补加盐酸的浓度和体积及后续赶酸时间对检测结果的影响,选择最佳的操作参数,实现对GB 5009.93—2017检测方法的优化,提升可操作性和稳定性。此外,采用优化后的检测方法测定不同地域生牛乳中硒的含量。实验结果表明,试样经微波消解处理后,在150 ℃条件下赶酸50 min,再补加5 mL 6 mol/L的盐酸,继续赶酸15 min,在该处理条件下检测结果相对偏差在2.6%～3.6%,加标回收率在93.04%～97.06%。对不同区域生牛乳中硒含量进行测定,结果表明,山东产地的硒含量最高,达47.94 μg/L,明显高于其他生牛乳。     

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