离子色谱-氢化物发生-原子荧光光谱(IC-HG-AFS)联用技术检测胶州湾海产品中硒的赋存形态

建立了离子色谱-氢化物发生-原子荧光光谱联用技术(IC-HG-AFS)测定胶州湾海产品中4种硒形态的方法。研究了色谱柱、流动相、提取剂、提取温度及其仪器条件等对硒荧光信号值的影响。试样用1.5 mol/L的氢氧化钾溶液作提取液,采用AS11-HC(250 mm×4.1 mm,5.0μm)阴离子色谱柱,20 mmol/L碳酸氢钠溶液/2%乙腈为流动相,1.0 m L/min流速,可在8 min内同时分离检测硒代胱氨酸(Se Cys)、硒代蛋氨酸(Se Met)、亚硒酸根Se(Ⅳ)和硒酸根Se(Ⅵ)。当4种形态的质量浓度范围为0~100μg/L时,各形态均得到良好的线性关系,线性相关系数均大于0.996,各形态的检出限分别为Se Cys 1.53μg/L,Se Met 1.72μg/L,Se(Ⅳ)0.30μg/L,Se(Ⅵ)1.06μg/L,相对标准偏差RSD均小5%(n=6),在最佳条件下,应用该方法测定了水产品中的硒形态,4种硒形态化合物加标回收率在86.1%~105.3%之间。该方法测定海产品中的硒形态准确、可靠、简便灵敏,为科学有效地评价海产品质量和开展风险评估提供技术支撑。     

高效液相色谱-氢化物发生-原子荧光光谱联用技术测定富硒大米中的5种硒形态

目的建立高效液相色谱-氢化物发生-原子荧光光谱法(high performance liquid chromatographyhydride generation-atomic fluorescence spectrometry,HPLC-HG-AFS)检测富硒大米中硒代胱氨酸(Se Cys2)、甲基硒代半胱氨酸(Me Se Cys)、亚硒酸根(Se IV)、硒代蛋氨酸(Se Met)和硒酸根(Se VI)的方法。方法选择Hamilton PRP-X100阴离子交换色谱柱,对流动相浓度、p H值以及提取条件进行选择优化。样品采用链霉蛋白酶E水解超声提取方式,使用40 mmol/L的磷酸氢二铵溶液(p H 6.0)作为流动相。结果 20 min内可以完全分离5种硒形态,各种硒形态标准曲线线性相关系数(r)均大于0.999,检出限分别为3.7、1.7、1.2、4.2、7.2μg/L。加标回收实验显示富硒大米中硒的主要存在形态即硒代蛋氨酸回收率范围在95.1%~98.2%,其他4种硒形态回收率范围均在80.4%~102.5%。结论本方法可以快速、准确地测定大米中硒的5种形态。     

阴离子交换色谱-氢化物发生-原子荧光光谱联用测定片剂类富硒保健品中4种形态硒

目的建立了阴离子交换色谱-氢化物发生-原子荧光光谱联用测定富硒保健品中硒酸根[Se(Ⅵ)]、亚硒酸根[Se(Ⅳ)]、硒代胱氨酸(SeCys_2)和硒代蛋氨酸(SeMet)的方法。方法采用Hamilton PRP-X100阴离子交换柱(250 mm×4.1 mm,10μm),以40 mmol/L磷酸氢二铵(pH=6.0)为流动相,在12 min内可完全分离4种硒形态。结果 Se(Ⅳ)、Se(Ⅵ)、SeCys_2和SeMet的检出限分别为0.85、1.07、0.91和1.73μg/L,标准曲线相关系数均0.999 5,加标回收率为80.2%~108.7%,相对标准偏差(RSD)均5.0%。比较了不同提取方法对片剂类富硒保健品中4种硒形态的提取效果,以亚硒酸盐为硒源的样品采用0.6 mol/L盐酸提取效果理想,提取率92%;含有有机硒的保健品采用蛋白酶K提取,提取率82%。结论本方法快速、简单、准确,适用于测定片剂类富硒保健品中硒形态,为监督富硒保健食品的质量提供技术支持。     

超声辅助酶法提取-高效液相色谱-电感耦合等离子体质谱联用分析食品中无机硒和硒氨基酸6种硒形态

建立了超声辅助酶法提取-高效液相色谱-电感耦合等离子体质谱联用同时测定食品中无机硒和硒氨基酸等6种硒形态的新方法。对影响硒形态分离及提取的诸因素如提取方式、流动相pH、浓度、甲醇含量、流速和柱温等进行详细考察和优化,同时利用碰撞反应池,有效地消除了复合离子的干扰,提高了检测灵敏度。该方法在9.50 min内使亚硒酸盐(Se(IV))、硒酸盐(Se(VI))、硒胱氨酸(SeCys_2)、硒蛋氨酸(SeMet)、甲基硒代半胱氨酸(MeSeCys)和硒代乙硫氨酸(SeEt)等6种目标分析物完全达到基线分离,各物质的检出限为(0.012~0.60)μg Se/L,线性范围达3~4个数量级,相对标准偏差(RSDs,n=7)为4.0%~8.2%;将该方法应用于食品中硒形态的分析,其加标回收率为81.6%~108.6%。方法具有操作简单方便、快速高效、灵敏度高和环境友好等优点,可满足食品中硒形态定量分析     

高效液相色谱-电感耦合等离子体质谱法检测富硒苹果中5种硒形态

目的建立高效液相色谱-电感耦合等离子体质谱联用技术(high performance liquid chromatographyinductively coupled plasma mass spectrometry,HPLC-ICP-MS)测定富硒苹果中5种硒形态的方法。方法对样品提取方法、流动相的类型、浓度、p H值等条件进行考察及确定,采用柠檬酸超声提取的方式处理样品,流动相为浓度为5 mmol/L、p H=5.0的柠檬酸溶液。选用Hamiltion PRP-X100阴离子分析柱,色谱进样量为100μL,质谱采用碰撞池模式进行测定。结果本方法在15 min内可以完全分离5种硒形态,硒代胱氨酸(Se Cys2)、甲基硒代半胱氨酸(Me Se Cys)、亚硒酸根(Se(Ⅳ))、硒代蛋氨酸(Se Met)、硒酸根(Se(Ⅵ))的检出限分别为0.6、0.7、1、0.9、1μg/L,样品加标回收率范围为82.1%~98.3%,相对标准偏差为1.6%~3.8%。结论本方法可以简单、快速、准确地测定富硒苹果中硒的5种形态。     

HPLC-ICP-MS联用检测转基因大豆中的硒形态

本文研究建立了高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用检测转基因大豆中的硒酸盐(Se VI)、亚硒酸盐(Se IV)、硒代蛋氨酸(selenomethionine,Se Met)、硒代胱氨酸(selenocystine,Se Cys2)和硒代乙硫氨酸(selenoethionine,Se Et)的方法。探讨了色谱柱、流动相及其酸度对分离效果的影响,使用10 mmol/L的柠檬酸溶液(p H值4.5)作流动相,Hamilton PRP X-100色谱柱分离,碰撞反应池技术消除40Ar40Ar+和40Ar2H2+等多原子离子干扰,ICP-MS检测82Se同位素,在21 min内可完全分离检测5种硒形态。探讨了不同提取方法的提取效果,优化了提取条件,采用蛋白酶提取,针对美国进口的转基因大豆样品进行加标回收实验,结果表明采用蛋白酶提取,Se IV和Se VI的回收率在100%左右,Se Met的回收率在92.6%~109.3%之间,Se Cys2和Se Et的回收率为81.2%~95.9%。该方法可完全满足转基因大豆中的硒形态定量分析鉴定。     

水产品中甲基汞检测方法的优化与讨论

建立使用盐酸超声波辅助提取HPLC-ICP-MS联用技术测定水产品及制品中甲基汞的分析方法。水产品及制品用5 mol/L盐酸提取,超声水浴提取60 min。流动相A为0.01 mmol/L乙酸铵+0.3%L-半胱氨酸(p H 3.0),流动相B为甲醇, V (流动相A)︰V (流动相B)=97︰3。使用C18反相高效液相色谱柱(4.6 mm×250 mm, 5μm)等度洗脱,202Hg为ICP-MS的检测离子,可6 min实现2种形态汞的完全分离。该方法的线性范围为0～10 ng/m L (r≥0.999 8),检出限为0.9μg/kg,加标回收率为80.8%～100%, RSD为0.80%～4.55%(n=6)。该方法分离时间短、准确、简便、可行、易于操作,在实验室检测方面具有一定的应用价值。     

高效液相色谱-电感耦合等离子体质谱法测定富硒食用菌中的4种硒形态

目的建立富硒食用菌中硒代胱氨酸(Se Cys)、4价硒(Se(IV))、硒代蛋氨酸(Se Met)、6价硒(Se(VI))4种硒形态的高效液相色谱-电感耦合等离子体质谱(high performance liquid chromatography-inductively coupled plasma-mass spectrometry,HPLC-ICP-MS)的分析方法。方法以Hamilton PRP-X100为色谱分离柱,以40mmol/L磷酸氢二铵(pH 6.0)为流动相,对富硒食用菌中4种硒形态进行分离,利用电感耦合等离子体质谱法对质量数为77的硒同位素(~77Se)进行定量检测,样品提取采用蛋白酶(来源于地衣芽孢杆菌)为提取剂,60℃水浴提取1 h。结果 4种硒形态在0~100μg/L浓度范围内线性良好,相关系数r~2大于0.997,检出限在2μg/L以下。结论该方法适用于富硒食用菌中硒的形态分析。     

水产品中不同形态汞的高效液相色谱-原子荧光光谱分析研究

建立高效液相色谱与原子荧光光谱联用测定水产品中甲基汞及其他形态汞的检测方法。方法 样品经盐酸超声提取后离心过滤,以5%乙腈-4.62g/L乙酸铵-1.2g/L半胱氨酸溶液作流动相,经反相C₁₈色谱柱分离后无需氧化和紫外消解,直接由原子荧光光谱仪检测,外标法定量。结果 甲基汞、乙基汞和无机汞的最佳线性范围为0～50μg/L,r＞0.9990,检出限为0.5～1.5μg/L,精密度RSD＜6%,加标回收率为78%～120%,鱼肉标准物质中甲基汞测定值在参考值范围内。结论 该法操作简便灵敏,结果准确可靠,适合于水产品中汞形态的测定。     

液相色谱——氢化物发生原子荧光光谱法测定富硒稻谷中硒的形态

建立了富硒稻谷中硒代胱氨酸(SeCys)、亚硒酸根(Se(IV))、硒代蛋氨酸(SeMet)、硒酸根(Se(VI))4种硒形态的高效液相色谱-氢化物发生原子荧光光谱分析方法。稻谷样品采用链霉蛋白酶E酶解提取,40 mmol/L磷酸氢二铵为流动相,经汉密尔顿阴离子交换柱分离后的溶液引入仪器进行氢化物发生-原子荧光光谱法测定。结果表明,4种硒形态标准曲线线性关系良好(R~2≥0.999 0),方法检出限为0.008 01-0.059 25 mg/kg,回收率为85.9-103.9%,RSD3%。本方法前处理简单,灵敏度高,能有效地分离并检测出稻谷中多种硒形态含量。     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

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 Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.     

National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the "13~(th) Five-Year Plan"

In Apri Commi major p Plan＂ （h 2014, the National Development and Reform ssion issued an announcement for selection of reliminary research projects for the ＂13th Five-Year ereafter referred to as ＂The Announcement＂）     

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 latest scientific     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

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.