固相萃取-高效液相色谱法测定地表水中 4种紫外吸收剂的含量

目的建立固相萃取-高效液相色谱方法检测地表水中4种紫外吸收剂含量的方法。方法采用固相萃取方法净化并浓缩大体积的样品,优化固相萃取条件,用高效液相色谱法检测4种紫外吸收剂的含量,并计算方法的线性范围、回收率、检出限和精密度等参数,并应用本方法检测湘江水和池塘水中紫外吸收剂的含量。结果通过应用固相萃取前处理样品和高效液相色谱法检测样品,本方法检测低限(LOD)达到了2.2~3.7μg/L,线性范围0.100~100μg/m L,回收率72.6%~93.3%,相对标准偏差(RSD)2.61%~4.37%。结论本方法简便、快速、稳定,能够满足实际检测的需要,可以为地表水中危害因子的检测和监控提供技术支持。     

固相萃取-高效液相色谱联用检测饮用水中的磺酰脲类除草剂

本研究基于固相萃取-高效液相色谱联用技术,建立了同时检测饮用水中两种磺酰脲类除草剂-苯磺隆、氯磺隆农药残留的方法。用甲基丙烯酸、乙二醇二甲基丙烯酸酯、偶氮二异丁腈分别作为功能单体、交联剂和引发剂,合成新型的高选择性材料,并将此吸附材料用做固相萃取的吸附剂。同时对洗脱剂的种类、体积以及样品的pH进行了优化。结果表明,在0.1 mg/L~5 mg/L的范围内两种物质线性关系良好,最低检出限分别为0.74μg/L和0.81μg/L,7次重复实验精密度分别为1.30%和2.10%。最佳的洗脱条件下,在饮用水中加标三个不同的浓度(10μg/L、15μg/L、20μg/L)的苯磺隆和氯磺隆混合物,经固相萃取后测得两种目标物的回收率可达到70.14~80.24%和76.52~106.03%。结果表明该方法可以用于饮用水中磺酰脲类除草剂的定量研究。     

固相萃取-高效液相色谱法同时测定饮用水中4种痕量双酚类化合物

建立了固相萃取-高效液相色谱法同时测定饮用水中4种痕量双酚类化合物。取100 g饮用水过Pro Elut PLS 200 mg/6 m L固相萃取柱,5 m L甲醇洗脱,氮吹至干后用1 m L甲醇再溶解,溶液过0.45μm微孔滤膜,上机待分析。4种目标化合物采用Agilent 5 TC-C18(2)(4.6 mm×250mm,5μm)分离;柱温为30℃;流动相A为水-甲醇(v/v),梯度洗脱;流速为1.0 m L/min。结果表明,该方法的检出限均为0.002 mg/kg,定量限均为0.008 mg/kg。4种目标化合物在(0.8~100.0)mg/L范围内均呈良好的线性关系,相关系数均大于0.999,加标回收率在91.9%~103%之间,相对校准偏差(RSD)小于3.22%。该方法前处理简单、快速,灵敏,适用于饮用水中4种双酚类化合物的测定。     

高效液相色谱法测定能量饮料中多种水溶性维生素

研究利用反相液相色谱法测定能量饮料中七种水溶性维生素(VC、VPP、VB1、VB2、VB5、VB6、叶酸)的方法。样品利用Supelco C18固相萃取柱(500mg/6ml)萃取后,直接注入高效液相色谱柱Phenomenex C18(250mm×4.6mm,5μm),采用等度洗脱,流动相为0.1mol/L KH2PO4(pH7.0)-甲醇(90:10,V/V),流速为0.5ml/min。根据各个化合物的保留时间以及UV谱图与标准谱图的对比可以确认各化合物。该方法的检测限为0.05～0.2mg/L,平均回收率为94.71%～97.03%。     

毛细管SPE-GC法测定纺织品中邻苯二甲酸酯

建立了新型毛细管固相萃取-气相色谱法检测纺织品中邻苯二甲酸酯(PAEs)的方法。通过比较筛选出毛细管固相萃取柱的最佳萃取剂,并优化萃取条件,净化富集待测物质后与气相色谱联用进行定性定量检测。采用的毛细管内固相萃取条件为:选取C18中的萃取剂为毛细管固相萃取剂,1.2μL甲醇和1.2μL超纯水依次活化,上样速率0.5μL/min,热脱附。该方法在1~1 000μg/L质量浓度范围内线性关系良好;DMP、DEP和DBP的最低检出限分别是4.1μg/L、4.8μg/L和5.4μg/L;加标回收率分别是84%~99%、88%~97%和84%~98%;相对标准偏差(RSD)分别为5.34%、4.23%和6.02%。     

印染废水中酸性橙染料的固相萃取-HPLC法测定

建立了印染废水中酸性橙I、酸性橙II、酸性橙IV和酸性橙G的固相萃取-高效液相色谱测试方法。样品经固相萃取小柱净化、浓缩,在Zorbax SB-C18柱上,以甲醇/乙酸铵(20 mmol/L)溶液为流动相进行梯度洗脱分离,在470 nm波长处进行检测,外标法定量。4种酸性橙染料在0.5~50.0 mg/L范围内均具有良好的线性关系,相关系数大于0.999,最低定量检出限为0.05~0.10 mg/L,回收率在88.7%~102.8%,RSD在1.5%~6.4%。     

固相萃取-高效液相色谱法测定畜禽肉中复合硝基酚钠残留

通过碱性溶液提取,再用正己烷萃取除去脂肪,用乙酸调p H为酸性条件后用乙酸乙酯-异丙醇反萃取,浓缩后再通过混合阴离子固相萃取柱净化,最后采用高效液相色谱分离检测。结果:三种复合硝基酚钠组分在0.05~1.0μg/m L范围内其浓度与峰面积呈线性,相关系数均可达到0.999;通过萃取、反萃取以及固相萃取等多种手段净化,样品基质几乎无干扰,检出限可达到0.003~0.005 mg/kg;通过对0.25、0.5、1.0μg进行加标测试,其回收率在81%~95%之间,相对标准偏差均小于10%。     

全自动固相萃取-高效液相色谱法同时测定饮用水中3种微囊藻毒素

建立全自动固相萃取-高效液相色谱法同时测定饮用水中3种微囊藻毒素的方法。采用全自动固相萃取仪代替传统的前处理方式,对大体积水样进行富集,以KH2PO4(p H=3.0)-甲醇(43∶57,v∶v)为流动相,采用二极管阵列检测器进行检测,结果 3种微囊藻毒素在0.1~10.0μg/m L范围内线性关系良好,相关系数r2≥0.999,3种不同微囊藻毒素的检出限均可达到0.05μg/L(S/N=3),加标回收率在86.3%~99.7%范围内,标准偏差为1.70%~2.72%(n=6),该方法用于测定饮用水中3种微囊藻毒素具有操作简单、快速,精密度高、准确可靠等特点。     

超高效液相色谱-三重四极杆质谱联用检测饮用水中N-亚硝胺类消毒副产物

为评估饮用水中新型消毒副产物N-亚硝胺对食品饮料行业带来的潜在风险,建立一种基于超高效液相色谱-三重四极杆质谱联用仪同时检测饮用水中9种N-亚硝胺类消毒副产物的方法.样品通过固相萃取,进入超高效液相色谱-质谱检测系统,经RRHD-C18色谱柱分离,以含有0.2％甲酸的10 mmol/L碳酸氢铵溶液和甲醇作为流动相梯度洗...     

在线固相萃取-高效液相色谱检测功能饮料中V_(B_(12))

建立了在线固相萃取-高效液相色谱直接检测功能饮料中V B12的方法,采用将双泵技术及阀切换技术结合在线固相萃取技术,将功能饮料中的大部分干扰物质去除后,对样品进行分析,降低了干扰,提高了灵敏度。在线固相萃取技术是一种简单、灵敏、高效的V B12检测手段,可以不需要对功能饮料离线处理,直接对V B12进行检测,检出限为0.54μg/L,回收率为101.29%。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press