分子印迹固相萃取-HPLC法检测食品中4种喹诺酮类抗生素

目的:建立检测鸡肉鸡蛋中4种喹诺酮类抗生素的分子印迹固相萃取-高效液相色谱(紫外检测器)的分析方法。方法:采用乳液聚合法制备诺氟沙星印迹聚合物(MIPs),采用扫描电镜和红外光谱对印迹聚合物进行表征。采用印迹聚合物为固相萃取剂,优化了影响萃取效率的参数包括淋洗剂的种类及用量、洗脱剂的种类及用量。结果:在优化的实验条件下,4种喹诺酮类抗生素在1.5～100μg/mL浓度范围内呈良好线性关系(r 0.992),方法的检出限(S/N=3)为0.04～0.4μg/mL,鸡肉鸡蛋样品中喹诺酮类抗生素的加标回收率为82.0%～96.0%,相对标准偏差(RSD)范围在3.9%～6.5%。结论:该方法快速、灵敏、可靠,能够满足食品中喹诺酮类抗生素多残留检测要求。     

液相色谱-串联质谱法测定鸡蛋中的喹诺酮类和四环素类抗生素

应用液相色谱-串联质谱法技术,建立鸡肉中喹诺酮类和四环素类抗生素的检测方法,并对宁夏地区市售鸡蛋进行分析。鸡蛋样品经EDTA-Mcllvaine缓冲溶液超声提取,玻璃纤维滤膜过滤,HLB固相萃取柱净化,乙腈-0.1%甲酸水溶液为流动相,用Waters Atlantis T₃色谱柱分离,以电喷雾正离子模式进行质谱测定。三个加标水平下喹诺酮类抗生素回收率为80.0%~114.0%,相对标准偏差小于12.0%,检出限(S/N=3)为0.2 μg/kg,定量限(S/N=10)为0.8 μg/kg;四环素类抗生素的平均回收率为84.5%~110.0%,相对标准偏差小于12.0%,检出限(S/N=3)为0.2 μg/kg,定量限(S/N=10)为0.8 μg/kg。该方法操作快速简单、重现性好,可用于鸡蛋中喹诺酮类和四环素类抗生素的检测。     

分散固相萃取结合液相色谱-串联质谱法测定淡水鱼中9种磺胺类和3种喹诺酮类药物残留量

目的 采用分散固相萃取结合液相色谱-串联质谱仪,建立淡水鱼中9种磺胺和3种喹诺酮类药物的分析方法。方法 淡水鱼肉样品用1%甲酸乙腈提取,提取液经盐析后取乙腈层,用分散固相萃取净化包净化,目标物用C18色谱柱（2.1×50 mm,1.7 μm）分离,采用0.1%甲酸乙腈作为流动相进行梯度洗脱,利用电喷雾离子源正离子多反应监测模式进行测定,内标法定量。结果 9种磺胺和3种喹诺酮类药物在 1.0~50.0 ng/mL 浓度范围内线性关系良好, 相关系数均大于 0.999。检出限和定量限分别为 0.1~1.0 μg/kg、1.0~5.0 μg/kg,在3个不同浓度添加水平下的平均回收率为84.4%~114.0%,相对标准偏差（relative standard deviation, RSD）为 1.2%~7.8%(n=6)。结论 该方法操作简单、快速,灵敏度高,适用于淡水鱼中磺胺和喹诺酮类兽药残留测定。     

磁性固相萃取液质联用法测定植物油中的黄曲霉毒素

目的建立基于磁性多壁碳纳米管的磁性固相萃取结合高效液相色谱串联质谱测定植物油中黄曲霉毒素的方法。方法样品加入正己烷后,用pH为3.0、体积分数为12.5%的乙腈-水溶液提取,而后加入MWCNTs-Fe3O4进行磁性固相萃取。对影响磁性固相萃取的条件如萃取剂、吸附剂用量、吸附时间、洗脱剂、洗脱时间等进行优化。结果黄曲霉毒素AFB1、AFB2、AFG1和AFG2在其线性范围内线性关系良好,相关系数均大于0.994,方法检出限为0.02~0.05μg/kg,定量限为0.08~0.15μg/kg。在0.10、1.00和5.00μg/kg 3个添加水平下,4种黄曲霉毒素平均回收率在75.1%~96.5%之间,相对标准偏差在3.2%~6.2%之间。结论该方法简便、快速、高效、准确,可用于植物油中黄曲霉毒素的检测。     

QuEChERS-超高效液相色谱-串联质谱法同时快速测定肉类食品中多种抗生素残留

目的建立能同时检测肉类食品中20种磺胺和8种喹诺酮类抗生素残留的Qu ECh ERS-超高效液相色谱-串联质谱法(UPLC-MS/MS)。方法样品加1%甲酸乙腈提取,经分散固相萃取净化后,采用Waters C18(2.1 mm×100 mm,1.7μm)色谱柱分离,梯度洗脱,采用电喷雾-正离子多反应监测模式,外标法定量。结果 28种抗生素在各自浓度范围内线性关系良好,相关系数(r)为0.997 5~0.999 6,检出限(LOD)为0.17~0.91μg/kg(S/N=3),磺胺类抗生素回收率在70.9%~115.2%之间,RSD在2.8%~15.9%(n=6)之间;喹诺酮类抗生素回收率在71.3%~112.3%之间,RSD在2.5%~14.6%(n=6)之间。结论建立的方法准确、快速、灵敏度高,可对动物源性食品中多种抗生素残留进行快速分析。     

超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法测定牛奶中19种喹诺酮类抗生素

建立基于超高效液相色谱-四极杆/静电场轨道阱高分辨质谱筛查和确证牛奶中19种喹诺酮类抗生素的方法。牛奶样品经酸化乙腈提取并沉淀蛋白,PRiME HLB固相萃取柱净化,用Waters Acquity BEH C18柱(2.1 mm×100 mm,2.5μm)分离,以乙腈和0.1%甲酸水溶液进行梯度洗脱,在全扫描(full MS)-数据依赖扫描(ddMS2)模式下检测。结果表明:19种喹诺酮类抗生素的精确质量相对偏差小于3.0×10-6,在0.2~200 ng/mL范围线性关系良好;检出限0.1~0.5μg/kg,定量限0.2~1.0μg/kg;加标水平0.2~10.0μg/kg时,方法回收率62.1%~100.4%,相对标准偏差低于10%。该方法简便、快速、准确,适用于牛奶中19种喹诺酮类抗生素的快速筛查和定量分析。     

分散固相萃取-超高效液相色谱-串联质谱法测定豆芽中6种喹诺酮类药物

本文建立了豆芽中恩诺沙星、环丙沙星、氧氟沙星、诺氟沙星、洛美沙星、培氟沙星6种喹诺酮类药物残留的分散固相萃取-超高效液相色谱-串联质谱的快速测定方法。豆芽样品中6种喹诺酮药物采用1%甲酸乙腈提取,提取液经N-丙基乙二胺(PSA)、十八烷基键合硅胶(C₁₈)、无水硫酸镁(MgSO₄)、石墨化碳(GCB)4种填料净化,净化液过滤膜后经ACQUITY UPLC BEH C₁₈色谱柱,甲醇-0.1%甲酸水流动相梯度分离,采用UPLC-MS/MS多反应监测模式进行测定,同位素内标法定量。结果显示:6种喹诺酮类药物在1.0~100.0 μg/L浓度范围内线性关系良好(r≥0.9982),检出限为0.1~0.3 μg/kg,定量限为0.3~1.0 μg/kg,在2、4、20 μg/kg三个浓度添加水平的回收率为96.53%~106.94%,相对标准偏差为2.73%~7.60%。该方法快速简便、灵敏度高、准确度高、重现性好,适用于豆芽样品中6种喹诺酮类药物的同时检测。     

固相萃取-超高效液相色谱串联质谱法测定牛奶中6种头孢菌素类抗生素

目的建立固相萃取超高效液相色谱串联质谱(SPE-UPLC-MS/MS)同时检测牛奶中6种头孢菌素类抗生素含量的方法。方法样品经0.05 mol/L的磷酸氢二钾缓冲溶液提取,HLB固相萃取柱净化,液相色谱串联质谱法测定,采用多反应监测模式进行定性和定量分析。结果 6种头孢菌素类抗生素的检出限(S/N=3)和定量限(S/N=10)范围分别为0.05~0.4μg/kg和0.1~1.6μg/kg。样品加标回收率范围为66.3%~110.0%。结论该方法便捷、快速、高效,能够满足牛奶中头孢菌素类抗生素的检测。     

超高效液相色谱-串联质谱法测定禽蛋类中4种四环素类抗生素残留量

目的 建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)测定禽蛋类中4种四环素类(tetracyclines, TCs)抗生素残留量的分析方法。方法 样品经含50 μg/mL蛋白酶K—0.1 mol/L EDTA-Na2溶液提取, Prime HLB固相萃取小柱净化, 洗脱液用氮气吹至近干, 用含甲醇和0.1%甲酸水(4+6)溶液溶解, 采用多反应监测正离子模式, 定性和定量测定禽蛋类中的四环素、土霉素、金霉素、强力霉素等4种四环素类抗生素。结果 4种四环素类抗生素在5~200 μg/L范围内呈现良好的线性关系, 相关系数均大于0.999; 方法的检出限为0.3 μg/kg, 定量限为1.0 μg/kg; 添加水平为20.0~200 μg/kg时, 平均回收率为80.5%~124%, 相对标准偏差(relative standard deviation, RSD)为0.89%~ 6.8%。结论 该方法简单、快捷, 可作为禽蛋类中四环素类抗生素的检测方法。     

SPE-GC/MS测定苹果梨中19种有机氯农药残留（英文）

采用固相萃取技术结合气相色谱—质谱(SPE-GC/MS)技术建立了同时检测苹果梨中19种农药残留的分析方法,并对样品预处理过程中萃取剂、萃取剂用量、取样量、固相萃取柱、洗脱剂等条件进行优化,采用选择离子监测(SIM)模式,外标法定量。结果表明,19种农药在线性范围内线性关系良好(R2≥0.996 7);3个添加水平(20,40,200μg/kg)的回收率为86.1%~108.9%,相对标准偏差10%;19种农药检出限为3.0~6.0μg/kg,定量限为10.0~20.0μg/kg;该方法样品前处理简单、准确性好、灵敏度高,适用于苹果梨中19种农药残留的筛选与测定。     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.