LC-MS/MS测定新鲜水果蔬菜中LAE的方法

建立液相色谱串联质谱法(LC-MS/MS)测定新鲜水果和蔬菜中的防腐剂月桂酰精氨酸乙酯盐酸盐(ethyl lauroyl arginine hydrochloride, LAE)的分析方法。通过乙腈超声提取样品中的LAE, C18色谱柱分离, 0.1%甲酸水溶液和乙腈进行梯度洗脱,经质谱法检测,外标法定量。最佳提取条件为:提取溶剂为乙腈,超声提取时间为15 min。LAE的线性范围为0～10μg/L,线性相关系数为0.999 5。方法的检出限为1.0μg/kg,方法的定量限为3.0μg/kg;方法的加标回收率范围为78.1%～109.4%,符合GB 27404—2008标准规定。方法简单、便捷,适用于新鲜水果和蔬菜中LAE含量的测定。     

LC-MS/MS测定果汁饮料中乳酸链球菌素

该试验旨在建立LC-MS/MS测定果汁饮料中乳酸链球菌素的分析方法。通过含0.1%甲酸的20%乙腈水溶液超声提取样品中的乳酸链球菌素,C₁₈色谱柱分离,0.1%甲酸水溶液和乙腈进行梯度洗脱,经质谱法检测,外标法定量。结果表明,最佳提取条件为提取溶剂乙腈、超声提取时间15 min。乳酸链球菌素的线性范围在0~100μg/L之间,线性相关系数为0.9996。方法的检出限为20μg/kg,定量限为50μg/kg;在50,100和500μg/kg三个水平下进行加标试验,其加标回收率在79.5%~111.5%之间,相对标准偏差(RSD)<10%,符合GB 27404—2008相关规定。该方法简单、便捷,适用于饮料中乳酸链球菌素含量的测定。     

QuEChERS-高效液相色谱-串联质谱法联用测定鸡肉中磺胺类药物残留

目的建立QuEChERS-高效液相色谱-串联质谱法测定鸡肉中磺胺类药物残留量的分析方法。方法以乙腈为提取溶剂,氯化钠盐析分层,离心后上清液经C18填料萃取净化,用乙腈和0.1%(V:V)甲酸水溶液作为流动相进行梯度洗脱,EndeavorsilC18柱色谱柱进行色谱分离,在高效液相色谱-串联质谱仪上采用电喷雾正离子扫描模式(electrospray ionization, ESI+)检测,外标法定量。结果该方法在5～200μg/L范围内有良好的线性关系, 8种磺胺类药物残留的相关系数均大于0.99,方法检出限在3～6μg/kg范围,定量限在10～20μg/kg范围。分别在3个浓度水平20、100、300μg/kg加标,平均回收率在75.6%～115.2%范围,相对标准偏差在1.9%～12.4%范围。结论本方法操作简便,准确度和精密度好,可快速检测鸡肉中磺胺类药物的残留量。     

液相色谱-质谱法测定乳及乳制品中氯霉素类抗生素的含量

目的建立液相色谱-质谱法测定乳及乳制品中氯霉素类抗生素的残留量。方法液态奶、酸奶、奶粉样本经乙酸乙酯提取,经Waters Sep-pak C_(18)固相萃取小柱净化,至Agilent C_(18)(150 mm×2.1 mm,5μm)色谱柱分离,以乙腈:水(50:50,V:V)为流动相进行等度洗脱。质谱法采用电喷雾离子源负离子模式和多反应监测模式测定,以内标法定量。结果氯霉素、甲砜霉素、氟苯尼考3种待测物质在0.1~20 ng/m L范围内线性关系良好,线性相关系数都在0.9995以上;氯霉素的检出限为0.011~0.021μg/kg,甲砜霉素的检出限为0.042~0.100μg/kg,氟苯尼考的检出限为0.010~0.018μg/kg;氯霉素在0.05、0.5和1μg/kg 3水平上的加标回收率为83.1%~95.6%,甲砜霉素在0.1、1和2μg/kg 3水平上的的加标回收率为80.2%~102.1%,氟苯尼考在0.05、0.5和1μg/kg 3水平上的的加标回收率为81.3%~103.5%;氯霉素的相对标准偏差为4.4%~6.4%,甲砜霉素的相对标准偏差为4.1%~7.1%,氟苯尼考的相对标准偏差为3.7%~6.6%。结论本方法准确灵敏,适用于乳及乳制品中氯霉素类抗生素残留量的测定。     

固相萃取-超高效液相色谱串联质谱法检测甘蔗中3-硝基丙酸的方法研究

目的建立甘蔗中3-硝基丙酸的固相萃取-超高效液相色谱串联质谱检测方法。方法样品经乙腈萃取,Sep-pak氨基固相萃取柱净化,超高效液相色谱串联质谱法测定甘蔗中3-硝基丙酸含量。色谱柱为WatersACQUITY BEH C18柱(1.7μm,50 mm×2.1 mm),柱温40℃,样品温度10℃,进样体积5μl,流动相A为水,流动相B为乙腈,梯度洗脱。结果方法的线性范围为4.0～40.0μg/kg,基质加标工作曲线线性相关系数为0.998。方法的定性检出限为1.0μg/kg,定量检出限为4.0μg/kg。高、中、低3个浓度水平的加标回收率为92.5%～93.6%,相对标准偏差小于10%。结论本方法灵敏、快速、准确,可用于甘蔗中3-硝基丙酸的测定。     

超高效液相色谱-串联质谱法测定鸡肉和鸡蛋中氯霉素和甲硝唑

目的建立超高效液相色谱-串联质谱法检测鸡肉和鸡蛋中的氯霉素和甲硝唑。方法鸡肉和鸡蛋样品经乙腈沉淀蛋白,乙酸乙酯和乙腈同时提取,Oasis MCX柱净化,以乙腈-水为流动相,采用ACQUITY BEH C18(2.1 mm×100 mm,1.7μm)色谱柱分离,分别以电喷雾负离子和正离子模式进行质谱测定,内标法定量。结果分别以鸡肉和鸡蛋为加标基质,三个加标水平下氯霉素和甲硝唑的平均回收率为96.3%~110.5%,相对标准偏差小于7.0%,氯霉素和甲硝唑的检出限(S/N=3)为0.1μg/kg,定量限(S/N=10)为0.3μg/kg。结论该方法操作快速简单、重现性好,可用于鸡肉和鸡蛋中氯霉素和甲硝唑的含量测定。     

超高效液相色谱-串联质谱法检测禽畜肉中头孢曲松钠药物残留

建立超高效液相色谱-串联质谱法测定禽畜肉中头孢曲松钠药物残留量的方法。禽畜肉样品经乙腈-水溶液(8∶2,V/V)振荡涡旋，超声提取，QuEChERS法净化，通过BEH C18色谱柱进行分离，以0.1%甲酸和甲醇为流动相，采用多反应监测模式分析，电喷雾离子源正离子模式(ESI⁺)扫描，外标法定量。结果表明：头孢曲松钠线性关系良好，相关系数(R2)大于0.999；检出限为3.0μg/kg，定量限为9.0μg/kg；头孢曲松钠在不同禽畜肉基质中进行高、中、低3种添加水平的回收率实验，平均加标回收率为87.17%～105.21%，相对标准偏差为3.14%～6.13%。该方法简单、快捷、灵敏、准确、可操作性强，适用于监管机构快速检测禽畜肉中头孢曲松钠残留量。     

UPLC-MS/MS检测果蔬饮料中痕量吡虫啉

建立一种快速、有效的超高效液相色谱-串联质谱法测定果蔬饮料中痕量吡虫啉农药残留的方法。样品经0.1%醋酸-乙腈提取后,采用氨基固相萃取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,吡虫啉标准在0.5 ng/mL~50.0 ng/mL浓度范围内线性良好,相关系数r~2为0.999,检出限为0.15μg/kg,定量限为0.50μg/kg,加标回收率达到93.2%~96.9%。     

HPLC-MS/MS法测定安神类代用茶中19种镇静安神类非法添加物质

建立奶粉中地塞米松的高效液相色谱-质谱/质谱测定方法。样品经甲酸乙腈溶液超声提取,经Oasis PRiME HLB固相萃取柱净化后上样。色谱条件采用Waters XBridge C18柱(2.1 mm×150 mm,5μm),流动相为0.1%甲酸水溶液-乙腈梯度洗脱,流速为0.3 mL/min,柱温40℃,采用电喷雾正离子扫描模式。结果表明:该物质检出限为1.0μg/kg,定量限为3.0μg/kg,线性范围:0～20 ng/mL。加标回收率为90.7%～98.9%。该方法操作简单高效,重现性较好,适用于奶粉中地塞米松含量的测定。     

地方特色小杂粮农药残留检测分析研究

建立高效液相色谱-串联质谱法(LC-MS/MS)测定小杂粮中氨基甲酸酯类农药残留分析方法。样品以乙腈为提取剂,超声波提取。该方法加标回收率平均值为83.5%~103%,检出限在0.006μg/kg~0.031μg/kg,定量限在0.016μg/kg~0.085μg/kg范围内,相对标准偏差在0.83%~5.8%范围内。     

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.