超高液相色谱-串联质谱法检测乳与乳制品中氯酸盐和高氯酸盐的残留

建立了乳与乳制品中氯酸盐和高氯酸盐的超高效液相色谱-串联质谱联用的检测方法。试样中的目标物经0.1%甲酸水提取,乙腈沉淀蛋白,PRIME HLB固相萃取柱净化,Amide色谱柱分离,以10mmol乙酸铵溶液和乙腈为流动相进行梯度洗脱,在电喷雾电离源负离子(ESI-)多反应监测模式下,采用同位素内标法进行定性和定量分析。结果表明:高氯酸盐和氯酸盐分别在0.5μg/L~50μg/L和5μg/L~500μg/L范围内线性关系良好,高氯酸盐和氯酸盐的定量限分别为7.5μg/kg和15μg/kg。在7.5、15、30μg/kg三种加标水平下,高氯酸盐在乳与乳制品中的平均回收率为88.1%~107.6%,相对标准偏差2.2%~4.1%。在15、30、150μg/kg三种加标水平下,氯酸盐在乳与乳制品中的平均回收率为80.1%~102.8%,相对标准偏差2.4%~3.7%。该法操作简单,检测速度快、结果稳定可靠,适用于乳与乳制品中氯酸盐和高氯酸盐的检测。     

UPLC-MS/MS法测定乳制品中的氯霉素类药物

建立超高效液相色谱-串联质谱(UPLC-MS/MS)法测定乳与乳制品中氯霉素、甲砜霉素和氟苯尼考的检测方法。样品经乙腈及乙酸乙酯提取、正己烷脱脂、C18柱净化后,通过超高效液相色谱-质谱联用仪进行检测,内标法定量。各标准溶液在0.1～10μg/L范围内呈线性相关(r=0.999),不同基质样品中添加回收率为75%～114%,检出限为0.1μg/kg。结果表明,该方法是一种准确测定乳与乳制品中氯霉素、甲砜霉素和氟苯尼考的检测方法。     

高效液相色谱法测定婴儿奶粉中维生素B12

建立了奶粉中维生素B12的反相高效液相色谱的测定方法,奶粉经去蛋白质-糖分-超声提取-富集浓缩超滤后进高效液相色谱仪,采用C18色谱柱,水-乙腈流动相体系,梯度洗脱能够快速有效地分离奶粉中的维生素B12.线性范围为0.010μg/mL～10μg/mL,相关系数为0.9998,检出限为0.1 μg/100g,加标回收率为78.8％～84.0％.该方法适用于实际样品的测定,速度快、成本低,结果令人满意.     

高效液相色谱法测定保健食品中维生素D3的含量

目的建立用半制备型反相高效液相色谱系统纯化、正相高效液相色谱硅胶柱色谱分离测定保健食品中维生素D_3含量的方法。方法通过皂化排除样品中的干扰物质,再经乙醚萃取浓缩,将浓缩后供试品溶液注入反相高效液相色谱仪净化分离去除杂质,排除维生素A的干扰,再用正相分析色谱进行定量分析,以正己烷-正戊醇(997:3,V:V)为流动相,流速为1.0 mL/min,采用色谱柱Waters Nova-Pak?Silia分离,在254 nm检测波长下经紫外或二极管阵列检测器检测,外标法定量。结果维生素D_3浓度在0.297~9.506μg/mL范围内呈良好的线性关系,相关系数为1,平均回收率为100.55%~100.58%,相对标准偏差值为0.44%~0.72%。结论该方法快速准确,可适用于保健食品中维生素D_3含量的测定。     

QuEChERS—UPLC—MS/MS法同时测定羊奶中8种β-内酰胺类抗生素

建立QuEChERS净化样品,超高效液相色谱—串联质谱同时测定羊奶中8种β-内酰胺类抗生素的检测方法。样品以乙腈作为提取试剂,用C18和PSA吸附剂进行净化,以0.1%(V/V)甲酸水溶液—乙腈为流动相,反相C18色谱柱分离,正离子扫描,多反应监测模式进行质谱分析。结果表明,8种β-内酰胺类抗生素的线性关系良好,相关系数均大于0.986,样品加标回收率为83.8%~95.4%,相对标准偏差小于6.5%,方法检出限为0.25~1.00μg/kg,定量限为1.0~2.0μg/kg。该方法适用于羊奶及其它奶制品中β-内酰胺类抗生素的测定。     

固相萃取-高效液相色谱法测定水产品中的甲基睾酮残留量

建立水产品中甲基睾酮残留量的固相萃取-高效液相色谱测定方法。样品经乙醚振荡提取、蒸发浓缩、正己烷除脂、LC-C18柱净化后吹干定容,以甲醇-0.1%甲酸溶液(75:25,V/V)为流动相经反相高效液相色谱检测定量。方法在7.0～200μg/kg添加范围内的平均回收率为82.0%～86.0%,相对标准偏差均小于7%,定量限为7.0μg/kg。     

GPC-HPLC-FLD 法测定动植物油脂中的苯并(a)芘

建立动植物油脂中苯并(a)芘残留量的凝胶净化-高效液相色谱-荧光检测的测定方法。方法采用凝胶色谱净化系统处理样品,可除去油脂中甘油三酯等杂质的干扰。色谱条件：Hypersil ODS2(150mm×4.6mm,5μm)反相色谱柱,流动相为甲醇-水(94:6,V/V),流速1.0mL/min,激发波长365nm,发射波长406nm,柱温30℃。方法的检出限0.1μg/kg,线性范围0.1～50μg/kg,加标回收率92.0%～106.0%,相对标准偏差为1.86%(n＝6)。该法具有样品预处理简单、灵敏度高、精密度高等优点,可用于动植物油脂样品中苯并(a)芘的快速准确测定。     

高效液相色谱-二极管阵列法测定高蛋白食品中的三聚氰胺

建立用高效液相色谱-二极管阵列法测定高蛋白食品中的三聚氰胺的检测方法.对不同样品采用不同的前处理方法,然后用Agilent TC-C18 4.6×250 mm色谱柱,柱温为40℃,流动相为0.02 mol/L硫酸铵∶甲醇=94∶6(V∶V),流速0.8 mL/min,二极管阵列检测器于235 nm波长下进行检测,并以保留时间和三维光谱图相似性系数进行定性,外标法定量.不同样品的加标回收率为98.8%～101.5%,RSD小于1.2%.方法线性范围为0.1～150μg/mL,检测限为0.01μg/mL,相关系数R=0.999 9.     

超高效液相色谱-串联质谱法测定猪肉中巴氯芬的残留

目的建立超高效液相色谱-串联质谱法测定猪肉中巴氯芬残留量的方法。方法样品采用0.1moL/L盐酸-甲醇溶液(20:80,V:V)提取,混合型强阳离子交换柱(MCX)净化,经C_(18)反相色谱柱分离后,正离子扫描,多反应监测模式检测巴氯芬,基质标曲定量。结果该方法在1～500 ng/mL浓度范围内线性良好, r~2=1,检出限为1μg/kg,定量限为5μg/kg,回收率为75.28%～77.86%,精密度RSD10%。结论该方法灵敏度高、特异性强,适用于猪肉中巴氯芬残留量的分析。     

UPLC-MS/MS检测乳品饮料中的四环素类残留

建立一种超高效液相色谱-串联质谱法检测乳品饮料中四环素、土霉素、金霉素、强力霉素残留的分析方法。样品前处理用乙腈沉淀蛋白后,采用HLB小柱进行净化和富集。采用Waters Atalantis T3色谱柱(2.1 mm×150 mm,3μm)分离,以0.1%甲酸-乙腈为流动相的梯度洗脱模式下,4种四环素类抗生素在1.0 ng/mL~200.0 ng/mL浓度范围内线性良好,相关系数r~2为0.998 5~0.999 2,检出限为0.5μg/kg~2.0μg/kg,定量限为1.5μg/kg~6.0μg/kg,加标回收率达到82.5%~91.5%。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.