UPLC-MS/MS测定牛奶中9种青霉素

建立超高效液相色谱-串联四极杆质谱多反应离子监测模式同时测定牛奶中9种青霉素类抗生素(包括羟氨苄青霉素、氨苄青霉素、邻氯青霉素、双氯青霉素、乙氧柰胺青霉素、苯唑青霉素、苄青霉素、苯氧甲基青霉素、甲氧苯基青霉素)残留量的检测方法。样品采用乙腈沉淀蛋白、脱脂后,过HLB小柱净化、富集。以0.01 mol/L乙酸铵水(甲酸调节p H 4.5)-乙腈梯度洗脱,经Agilent Eclipse plus C18色谱柱(2.1×100 mm,粒径1.8μm)分离后,采用MRM模式进行定量定性分析。结果:结果表明9种抗生素在0.1μg/L~100μg/L范围内线性关系良好,高中低浓度回收率在67.7%~92.8%,相对标准偏差(n=6)小于15%,各组分定量限为0.1μg/kg~4μg/kg。     

超高效液相色谱-四极杆串联线性离子阱质谱法测定乳制品中8种青霉素类药物及其主要代谢产物

目的建立一种超高效液相色谱-四极杆串联线性离子阱质谱技术测定乳制品中8种青霉素类抗生素(青霉素G、氨苄西林、青霉素V、阿莫西林、苯唑西林、萘夫西林、氯唑西林、双氯西林)及其相应的代谢产物青霉噻唑酸(青霉素G噻唑酸、氨苄青霉噻唑酸、青霉素V噻唑酸、羟氨苄青霉噻唑酸、苯唑青霉噻唑酸、乙氧萘青霉噻唑酸、氯唑青霉噻唑酸、双氯青霉噻唑酸)残留的方法,并对市售乳制品中青霉素及青霉噻唑酸残留情况进行调查。方法乳制品样品中青霉素及青霉噻唑酸采用纯水超声提取,经乙腈沉淀蛋白,正己烷液液萃取除去脂肪,用氮气吹至近干,用乙腈-水(10∶90,V/V)复溶后,经0.22μm微孔滤膜过滤,经超高效液相色谱C_(18)柱(50 mm×2.1 mm,1.8μm)分离,选用乙腈-水(含0.1%甲酸)为流动相,梯度洗脱分离8种青霉素及相应青霉噻唑酸共16种组分;在优化的四极杆串联线性离子阱质谱条件下,采用ESI源、正离子模式、多反应监测方式,外标法定量,采用信息依赖采集扫描功能(IDA)结合增强子离子扫描(EPI)模式对检出阳性结果进行定性分析。结果方法的线性范围为1.0~200μg/L,8种青霉素及相应青霉噻唑酸在各种乳制品基质中均有良好的线性相关性,相关系数r在0.999 1~0.999 9之间,方法最低检测限为0.01~0.05μg/kg(固体乳粉)和0.002~0.010μg/kg(液体奶);方法回收率在80.0%~110.0%,相对标准差为0.16%~7.06%。结论该方法测定8种青霉素药物及相应代谢产物青霉噻唑酸的残留量简便、快速、定性准确,可以满足对青霉素类药物及其代谢产物残留的检测要求。     

液相色谱串联质谱法快速测定鱼肉中四聚乙醛残留量

建立测定鱼肉中四聚乙醛残留量的液相色谱串联质谱分析方法。样品经乙腈提取,提取液经盐析后采用N-丙基乙二胺和C18填料净化,净化液经0.1%甲酸溶液稀释后进样分析。分析时采用Acquity BEH C18,以0.1%甲酸溶液和乙腈作为流动相作梯度洗脱,电喷雾正电子(ESI+)模式电离,多反应监测(MRM)模式检测,内标法校准进行定量。四聚乙醛在0.05~5.0μg/L质量浓度范围内呈良好的线性,线性相关系数大于0.999,鱼肉样品中最低定量限为1.0μg/kg。鱼肉样品中添加1.0~2.0μg/kg的回收率在98.5%~100.8%之间,相对标准偏差均小于10%。     

液相色谱-串联质谱法测定河豚鱼和鳗鱼中9种青霉素类抗生素

目的建立高压液相色谱-电喷雾串联质谱(HPLC-MS-MS)同时测定河豚鱼和鳗鱼中9种青霉素残留量的检测方法。方法样品经乙腈-氨水溶液提取后,用C18色谱柱分离,乙腈-乙酸为流动相梯度洗脱,最后采用液相色谱-电喷雾串联质谱在正离子多反应监测模式下测定。结果在1.0～20μg/kg(LOQ～10LOQ)范围时,方法线性关系良好,相关系数大于0.999。在LOQ、2LOQ、4LOQ、10LOQ四个添加水平下青霉素的回收率在81.4%～109.7%之间,相对标准偏差在2.81%～7.12%之间,方法检出限是:萘夫西林、青霉素G、哌拉西林、青霉素V、苯唑西林为1.0μg/kg;阿莫西林、氨苄西林、氯唑西林、双氯西林为2.0μg/kg。结论此方法灵敏度高,准确性好,适用于水产品中青霉素的定量检测。     

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%。     

QuEChERS净化-高效液相色谱串联质谱法快速筛查乳制品中10种喹诺酮类抗生素

建立了乳制品中10种喹诺酮类抗生素的QuEChERS净化-高效液相色谱串联质谱快速筛查方法。将QuEChERS试剂加入待测乳制品中,旋涡混匀离心后将上清液转移至含无水硫酸镁及氯化钠的离心管中,取上层乙腈2.0 mL氮气吹干后用流动性初始比例定容,以0.1%甲酸水及甲醇-乙腈混合溶液为流动相梯度分离洗脱,电喷雾离子源正离子模式(ESI+)进行多反应监测扫描。结果显示10种喹诺酮类化合物在测定浓度范围内线性关系良好,各测定组分相关系数r≥0.998,空白样品在低、中、高3个浓度添加下测定方法平均回收率范围在63.2%～96.7%之间,精密度范围为4.32%～11.42%之间,10种喹诺酮化合物的方法检出限为1.0μg/kg,定量限为3.0μg/kg。该方法具有灵敏度高,精密度良好,相对于固相萃取净化方法具有前处理简单的特点,适用于乳制品中10中喹诺酮化合物的定量筛查检测。     

DSPE-LC-MS/MS法测定海红果中9种杀菌剂残留量

建立分散固相萃取(DSPE)-液相色谱-质谱法(LC-MS/MS)测定海红果中9种杀菌剂(嘧霉胺、百菌清、稻丰散、甲霜灵、三唑酮、五氯硝基苯、烯酰吗啉、咪鲜胺、苯醚甲环唑)残留量的检测方法。样品匀浆粉碎后经乙腈提取、氧化铝萃取剂净化后,采用Atlantis T3色谱柱分离,LC-MS/MS测定。结果表明:9种杀菌剂在5.0μg/L~500μg/L范围内,呈良好的线性关系,线性相关系数R~2≥0.999 3;检出限为0.03μg/kg~1.0μg/kg,定量限为0.1μg/kg~3.0μg/kg;回收率在80.4%~102.3%,相对标准偏差(RSD)在1.1%~5.8%之间。     

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。     

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。     

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。     

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.     

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.     

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.     

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.     

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.     

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.     

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.