超高效液相色谱法快速测定原料乳中的双氰胺

建立了超高效液相色谱检测原料乳中双氰胺的分析方法。采用甲醇提取样品中的双氰胺,HILICS色谱柱为分析柱,流动相为乙腈-10 mmol/L乙酸铵(90∶10,体积比),流速0.4 mL/min,检测波长230 nm。双氰胺在0.006 mg/L～10.0 mg/L范围内具有良好的线性关系,标准曲线方程为y=90.336x+0.994 6,R2=0.999 9。方法检出限为0.05 mg/kg,不同添加水平平均回收率在87.0%～91.6%之间,变异系数3.84%(n=6)。此方法操作简便,可在15min内完成快速检测,适用于原料乳中双氰胺残留的快速筛查。     

超高效液相色谱——三重四级杆质谱测定乳与乳制品中氯霉素的残留

建立了乳与乳制品中氯霉素残留的超高效液相色谱——三重四级杆测定方法。该方法采用电喷雾电离源、多重反应监测负离子模式,可对氯霉素残留进行定性和定量测定。该方法的检出限为牛奶0.05μg/kg,乳粉为0.1μg/kg,线性范围在0.4～30.0μg/L内的回归方程为y=798.97+1874.56x,r=0.9993,加标回收率75.0%～94.6%,相对标准偏差为4.2%～12.8%。该法具有样品处理简单方便,灵敏度高,分析时间短等优点,可以满足乳与乳制品中氯霉素残留的测定。     

高效液相色谱法测定乳与乳制品中 L-羟脯氨酸的含量

目的建立高效液相色谱法测定乳与乳制品中L-羟脯氨酸的含量。方法样品水解衍生后采用C18色谱柱,以乙腈和10 mmol/L乙酸钠(p H=5.0)为流动相,梯度洗脱,流速为1.0 m L/min,柱温35℃,荧光检测器进行检测。结果 L-羟脯氨酸检出限为0.5 mg/kg,线性范围为1.0~100.0μg/m L,加标回收率在95.3%~102.7%之间,相对标准偏差在1.46%~7.56%之间。结论该方法操作简便、准确、快速,提高了样品检出灵敏度,适用于测定乳与乳制品中L-羟脯氨酸的含量。     

同位素稀释-高效液相色谱-高分辨质谱法测定乳及乳制品中3种三嗪类农药

本文建立了乳及乳制品中莠去津、灭蝇胺和异丙甲草胺3种三嗪类农药残留的同位素稀释-高效液相色谱-高分辨质谱的测定方法。样品采用乙腈提取,经C₁₈固相萃取小柱净化后测定。以甲醇-0.1%甲酸水溶液为流动相梯度洗脱,待测物经Hypersil GOLD C₁₈色谱柱分离,最后用电喷雾正离子（HESI+）和全扫描/数据依赖二级扫描(Full MS/dd-MS2）模式进行定性定量检测。结果表明:3种三嗪类农药在1.0~50.0 ng/mL浓度范围内线性关系良好(R2≥0.99)。方法检出限为5 μg/kg,添加水平为5、10、25 μg/kg时,平均回收率为81.6%~104.0%,相对标准偏差为0.55%~4.14%。该方法适用于乳及乳制品中3种三嗪类农药残留的检测,灵敏度高、重现性好、结果可靠,为保障我国乳及乳制品的食品安全提供了技术支撑。     

液相色谱-串联质谱同位素稀释法测定奶粉中双氰胺的残留

目的 建立并优化高压液相色谱-串联质谱法快速检测奶粉中双氰胺残留的方法。方法 奶粉样品经1%三氯乙酸溶液沉淀蛋白后, 通过Sep-pak AC-2离子交换固相萃取柱净化样品提取液, 去除奶粉中其他复杂基质的干扰, 浓缩后用初始流动相复溶、过膜。采用电喷雾正离子电离(ESI+)模式和多反应监测(MRM)扫描模式, 通过Acquity BEH Amide(3.0 mm×150 mm, 1.7 μm)色谱柱分离检测双氰胺目标化合物, 同位素15N4-双氰胺稀释法定量。结果 该方法在50~1200 μg/kg范围内线性良好, 相关系数r>0.998, 在三种不同基质样品中的最低检测限与最低定量限分别为2.5 μg/kg和8 μg/kg, 加标回收率为93.4%~112.3%, 相对标准偏差均<10.3%。结论 该方法简便、灵敏、精确, 不仅筛选优化了液相、质谱条件参数, 同时优化了奶粉样品的前处理方法, 适用于奶粉中双氰胺残留的检测。     

乳与乳制品中硫氰酸盐的测定

本文利用紫外分光光度法测定乳与乳制品中硫氰酸钠的质量浓度。样品经沉淀过滤后,硫氰酸根遇铁盐反应生成血红色的硫氰酸铁,在450 nm下测其吸光值,用标准曲线法定量。本方法的线性范围为0.00~10 mg/kg,相关系数R=0.999 817,鲜奶的检出限为1.00 mg/kg,奶粉的检出限为2.00 mg/kg,回收率为90.76%~104.59%,相对标准偏差0.199%~0.366%。该方法具有操作简单、结果准确等特点,对乳与乳制品中硫氰酸盐的控制具有重要意义,适合在大中小企业推广。     

乳与乳制品中硫氰酸盐的测定

本文利用紫外分光光度法测定乳与乳制品中硫氰酸钠的质量浓度。样品经沉淀过滤后,硫氰酸根遇铁盐反应生成血红色的硫氰酸铁,在450 nm下测其吸光值,用标准曲线法定量。本方法的线性范围为0.00~10 mg/kg,相关系数R=0.999 817,鲜奶的检出限为1.00 mg/kg,奶粉的检出限为2.00 mg/kg,回收率为90.76%~104.59%,相对标准偏差0.199%~0.366%。该方法具有操作简单、结果准确等特点,对乳与乳制品中硫氰酸盐的控制具有重要意义,适合在大中小企业推广。     

离子色谱-电导检测法快速测定乳与乳制品中 硫氰酸根含量的研究

目的建立一种离子色谱-电导检测法快速测定乳与乳制品中硫氰酸根含量的方法。方法样品经水和甲醇震荡提取、离心后上清液用滤膜过滤后,AS16分离柱分离,由35 mmol/L氢氧化钾溶液等度洗脱,用电导检测器检测,外标法定量。结果方法的线性范围为0.02~20μg/m L,R=0.9990,检出限为0.1 mg/kg,相对标准偏差为0.89%~3.31%,回收率范围为96%~105%。结论该离子色谱法快速、准确、精密度高,适用于乳与乳制品中硫氰酸根的批量检测。     

超高效液相色谱串联质谱法快速测定乳及乳制品中三聚氰胺

建立快速、经济测定乳及乳制品中三聚氰胺的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。乳及乳制品样品中加入乙腈-水溶液,通过超声波提取和二氯甲烷液液萃取除去蛋白质、脂肪等杂质,进一步稀释后直接进样。经超高效液相色谱(UPLC)快速分离,采用电喷雾正离子(ESI+)多反应监测模式(MRM),实现对三聚氰胺的定性和外标法定量。乳及乳制品样品在1.2 min内完成分析,且具有良好的线性关系(r=0.999 1);方法检出限和定量限(LOQ)分别为0.005 mg/kg、0.017 mg/kg;在0.5～100μg/L的基质添加浓度范围内,平均回收率为91.3%～97.1%,相对标准偏差(RSD)小于9.03%。     

分散固相萃取离子色谱质谱法测定乳制品中硫氰酸盐质量浓度

建立了离子色谱质谱法测定乳制品中硫氰酸盐含量的方法。乳制品中硫氰酸盐经水超声提取后,用3%乙酸沉淀蛋白,以分散固相萃取法进行样品净化,提取液过0.22μm水相滤膜,离子色谱质谱联用仪检测,外标法定量。同时对样品净化方式,离子色谱-质谱连接方式,喷雾温度和锥孔电压等条件进行了优化。结果表明:硫氰酸盐在0.01~0.5 mg/L范围内线性良好,相关系数为0.996,测定限(以信噪比S/N≥3计)为0.2 mg/kg,定量限(以信噪比S/N≥10计)为0.6 mg/kg。在2.0,5.0,10.0 mg/kg三个添加水平下进行了回收率和精密度实验,加标回收率在91.0%~96.9%之间,相对标准偏差RSD(n=10)为5.78~9.81%。该方法操作简单、抗干扰能力强、灵敏度高、稳定性好、成本低廉,可用于乳制品中硫氰酸盐的日常检测。     

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