SPE-GC/MS外标法测定水产品中4种丁香酚类麻醉剂

建立了固相萃取/气相色谱-质谱法(GC-MS)测定水产品中4种丁香酚类(丁香酚、异丁香酚、甲基丁香酚和甲基异丁香酚)麻醉剂的分析方法。样品采用正己烷-丙酮混合液(3:1,v/v)提取,乙二胺-N-丙基硅烷(PSA)净化,浓缩后再经硅胶固相萃取柱净化,采用GC-MS测定,外标法定量。结果表明:4种丁香酚类麻醉剂在5.0~200 ng/mL范围内均呈现良好线性关系,相关系数均大于0.998,方法检出限(S/N=3)均为3.0 μg/kg,方法定量限(S/N=10)均为10.0 μg/kg。空白水产品样品在0.01、0.05、0.20 mg/kg等3个加标水平时,4种目标物的平均加标回收率为85.7%~102.5%,相对标准偏差(RSD)为3.3%~9.8%。此方法净化效果较好,灵敏度高,适合水产品中4种丁香酚类麻醉剂的定性和定量分析。     

GC-MS法同时测定水产品中6种丁香酚类麻醉剂的残留量

建立了同时检测水产品中6种丁香酚类麻醉剂残留量的气相色谱-质谱(GC-MS)检测方法。样品经乙腈超声提取,分散固相萃取净化后氮吹浓缩、定容,用气相色谱-质谱仪进行测定,外标法定量。6种丁香酚类化合物在1.0~200.0 μg/L的浓度范围内线性关系良好,相关系数R~2为0.9956~0.9995。又分别在罗非鱼、南美白对虾以及扇贝肌肉样品中添加1.0~10.0 μg/kg的混合标准溶液,测定平均回收率在82.2%~100.7%范围内,相对标准偏差在0.6%~7.4%之间。方法的定量限(LOQ),丁香酚、甲基丁香酚、异丁香酚、乙酰基异丁香酚为1.0 μg/kg,甲基异丁香酚和乙酸丁香酚酯为0.5 μg/kg。     

分散固相萃取-气相色谱法同时测定水产品中六种丁香酚类麻醉剂的残留量

建立了同时检测水产品中六种丁香酚类麻醉剂残留量的分散固相萃取-气相色谱检测方法。样品经丙酮进行提取,旋转蒸发浓缩后定容,采用分散固相萃取(DSPE)净化,用气相色谱仪进行测定,外标法定量。六种丁香酚类化合物在0.05~10.0μg/m L的浓度范围内线性关系良好,相关系数R2为0.9995~0.9999。又分别在罗非鱼、南美白对虾、鳗鲡以及梭子蟹肌肉样品中添加0.1~1.0mg/kg的混合标准溶液,测定平均回收率在80.3%~103.2%范围内,相对标准偏差在0.7%~5.4%之间。方法的定量限(LOQ),六种丁香酚类化合物(丁香酚、甲基丁香酚、异丁香酚、甲基异丁香酚、乙酸丁香酚酯、乙酰基异丁香酚)均为0.1mg/kg。     

固相萃取-高效液相色谱-荧光检测法测定水产品中4种丁香酚类化合物

目的建立固相萃取-高效液相色谱荧光法测定水产品中4种丁香酚类化合物(丁香酚、异丁香酚、甲基丁香酚、甲基异丁香酚)残留的方法。方法样品用乙腈提取,中性氧化铝和C18固相萃取柱净化,Inertsil ODS-SP C18柱(4.6 mm×250 mm,5μm)分离,以甲醇-乙腈(1∶1,V/V)和1%冰乙酸水溶液为流动相,荧光检测激发波长为280 nm,发射波长为320 nm,外标法定量。结果 4种丁香酚类化合物在各自范围内线性关系良好,相关系数均0.999,方法检出限为3.0~6.0μg/kg,方法定量限为10.0~20.0μg/kg,平均加标回收率为74.7%~103.0%,相对标准偏差(RSD)为2.6%~8.1%。结论本方法操作简便、灵敏度高、实用性强,适用于水产品中丁香酚、异丁香酚、甲基丁香酚、甲基异丁香酚的残留分析检测。     

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。     

QuEChERS-高效液相色谱法同时测定植物固体饮料中10种植物毒素

建立了植物固体饮料中原百部碱、侧柏酮、香豆素、黄连素、黄樟素、山道年、芦荟苷、细辛脑、异黄樟素、长叶薄荷酮10种植物毒素的QuEChERS结合超高效液相色谱的检测方法。样品经乙腈提取,应用QuEChERS技术净化,Wlech Xtimate C_8液相色谱柱(4.6mm×250mm,5μm)分离,流动相为甲醇-10 mmol/L乙酸铵水溶液(pH 3.5),通过PDA检测器进行检测。试验表明,10种植物毒素在0.005～154.200mg/L范围内线性关系良好,相关系数均0.997,方法检出限(S/N=3)为0.010～0.270mg/kg,定量限(S/N=10)为0.032～0.830mg/kg。阴性样品的3个添加水平的平均回收率在78.46%～100.77%,相对标准偏差(RSD,n=6)1.10%～3.07%,日间精密度为1.11%～2.73%。该方法操作简单,准确高效,适用于植物固体饮料种10种植物毒素含量的测定。     

高效液相色谱同时测定植物饮料中7种植物毒素

建立了同时检测植物饮料中原百部碱、香豆素、黄连素、山道年、细辛脑、长叶薄荷酮和芦荟苷A 7种植物毒素含量的高效液相色谱法。试样经HLB固相萃柱富集净化,甲醇洗脱,氮吹浓缩后用流动相起始梯度定容至1.0 mL,经Welch Ultimate XB-C18色谱柱（4.6 mm×150 mm,5 μm）分离,以甲醇-10 mmol/L乙酸铵水溶液（pH=3）为流动相梯度洗脱,通过紫外检测器进行检测。7种植物毒素化合物在0.20～100.00 mg/L范围内线性关系良好,相关系数均＞0.99,方法的检出限分别为0.2～6.5 μg/kg,定量限为0.8～21.6 μg/kg。分别对3种植物饮料样品进行加标回收率实验,回收率为67.1%～104.0%,相对标准偏差（n=6）为1.08%～5.12%。该方法操作简单,具有较高的准确度和精密度,适用于植物饮料中7种植物毒素含量的检测。     

全自动固相萃取-高效液相色谱-串联质谱法测定 蜂蜜中3种农药残留

目的建立蜂蜜中多菌灵、甲基托布津和乙基托布津3种农药的全自动固相萃取-高效液相色谱-串联质谱检测方法。方法蜂蜜样品经磷酸盐缓冲液(pH=7.8)溶解,稀释,全自动固相萃取净化后,采用高效液相色谱-串联质谱测定,内标法定量。结果 3种农药在2~100μg/L范围内呈良好的线性关系(r~20.99),定量限为5μg/kg。在5.0、10.0、20.0μg/kg 3个加标水平下,3种农药的回收率为75.6%~97.1%,相对标准偏差小于13.2%。结论该方法简单、快速,准确度和精密度良好,可用于蜂蜜中多菌灵、甲基托布津和乙基托布津的同时测定。     

超声萃取-气相色谱-质谱法测定烟用水基胶中的5种异噻唑啉酮杀菌剂

建立了超声萃取-气相色谱-质谱联用同时检测烟用水基胶中5种异噻唑啉酮杀菌剂的分析方法。烟用水基胶样品经二氯甲烷超声萃取30 min,静置取上清液并加入N,O-双(三甲基硅烷)三氟乙酰胺(BSTFA)衍生后进行GC-MS选择离子分析,内标法定量。结果表明:5种异噻唑啉酮待测化合物在0.40~16.00μg/m L范围内线性关系良好,R2为0.9973~0.9997;检出限(LOD)和定量限(LOQ)分别为0.004~0.15μg/m L和0.018~0.050μg/m L,回收率为90.2%~99.1%,相对标准偏差RSD为1.7%~5.7%。该方法具有简单、准确、灵敏等特点,应用于实际样品检测取得了良好效果。     

SPE-HPLC-MS/MS测定粮食中玉米赤霉烯酮和脱氧雪腐镰刀菌烯醇

建立了以乙腈-水(84∶16,v/v)为提取溶剂、正己烷萃取和HLB固相萃取(SPE)净化、水和乙腈C18反相色谱梯度洗脱、电喷雾负离子多反应监测模式(MRM)同时测定粮食中玉米赤霉烯酮(ZEN)和脱氧雪腐镰刀菌烯醇(DON)2种物质含量的HPLC-MS/MS检测方法。结果表明,ZEN和DON检出限(以信噪比S/N=3计)依次为0.1μg/kg和2μg/kg,定量限(以信噪比S/N=10计)依次为0.3μg/kg和6μg/kg;两者线性范围分别为0.20~25μg/L(相关系数r=1.000 0)和4.0~500μg/L(相关系数r=0.999 9);不同样品2种目标物3个水平的加标回收率在88.7%~102.3%之间,相对标准偏差(RSD)在2.4%~7.3%之间。应用该方法对所检小麦样品进行分析,结果均发现严重污染样品的2种目标毒素。     

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.     

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.     

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.     

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.