高效液相色谱-串联质谱法测定液体乳中氯酸盐和高氯酸盐

建立了液体乳中的氯酸盐和高氯酸盐高效液相色谱－串联质谱法的测定方法,样品经0.2%甲酸水－甲醇(10：90, v/v)提取,HLB固相萃取柱净化。经AcclaimTRINITYP1复合阴离子交换柱(100mm×2.1mm,3μm)洗脱。在流速 0. 5 mL/min下以乙腈－20mmoL/L甲酸铵溶液(70∶ 30,V/V)作为流动相,梯度分离。采用三重四极杆电喷雾离子源(ESI源)电离－多反应监测(MRM)－负离子监测模式检测,分别以氯酸根－_¹⁸O₃高氯酸根－_¹⁸O₄为内标物。进行内标法定量。氯酸盐和高氯酸盐分别在 0.0 ～50. 0 μg/kg和0.0 ～25. 0 μg/kg范围内线性关系良好,相关系数R_²都大于0.999。方法的测定低限分别为1.2μg/kg和1.0 μg/kg.回收率为80.6%～93.6%,RSD值为2.14%～6.68%,实验表明该方法提取率高,准确可靠,适用于液体乳中氯酸盐和高氯酸盐的定量分析。     

2015年我国部分地区市售食用植物油中黄曲霉毒素污染调查

目的 对我国8省738份市售食用植物油中4种黄曲霉毒素(AFB₁、AFB₂、AFG₁和AFG₂)污染状况进行调查。方法 首先用酶联免疫吸附(ELISA)法快速筛检市售食用植物油中黄曲霉毒素,再用超高效液相色谱(UPLC)法对阳性样品中4种黄曲霉毒素的含量进一步确证。结果 食用植物油样品中黄曲霉毒素总量的含量范围在0.06～221.00 μg/kg之间,平均为19.30 μg/kg。4种黄曲霉毒素的污染以AFB₁为主,其检出率为17.21%(127/738),平均含量为16.20 μg/kg。其次是AFB₂、AFG₁和AFG₂。花生油中黄曲霉毒素污染较重,AFB₁超标率为11.57%(25/216)。来自广西的植物油样品中黄曲霉毒素污染较重,AFB₁超标率达19.23%(20/104)。此外,散装植物油中黄曲霉毒素污染含量高于定型包装样品。95.45%(126/132)的阳性样品检出2种或2种以上的黄曲霉毒素。结论 我国食用植物油存在黄曲霉毒素协同污染现象,并以AFB₁为主。花生油、来自广西的植物油样品以及散装食用植物油样品中黄曲霉毒素污染较高,需重点监测并加以监管。     

自动QuEChERS结合气相色谱-串联质谱法测定花生油中172种农药残留

目的：基于自动QuEChERS方法建立了花生油中172种农药残留的气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)快速检测技术。方法：花生油样品加水后,加入15 mL乙腈提取,放入自动QuEChERS前处理设备,以N-丙基乙二胺(primary secondary amine,PSA)和十八烷基硅烷键合硅胶(C18)为填料进行净化。净化后,取2 mL上清液,在氮气气流下吹至近干,用1 mL乙酸乙酯复溶后,过0.22 μm有机微孔滤膜,应用气相色谱－串联质谱(GC-MS/MS)检测,HP-5MS UI气相色谱柱分离,程序升温,在多重反应监测(MRM)模式进行测定,采用基质匹配外标法进行定量。结果：方法所检测的172种农药的线性决定系数(R_²)均大于0.995,检出限范围为1～5 μg/kg,定量限范围为2～10 μg/kg;在10 μg/kg、50 μg/kg和100 μg/kg 3个添加水平下,平均回收率在70.1%～112.8%、72.6%～114.3%、71.8%～114.9%范围内,相对标准偏差(RSDs)均小于15.0%(n=6)。结论：该方法操作简单,灵敏高效,能够满足花生油中多农药残留检测的需求,也可以为复杂基质的自动化前处理提供参考。     

高效液相色谱-串联质谱法测定食品接触材料中双酚S的迁移量

建立了液相色谱-串联质谱测定食品接触材料中双酚S的迁移量的分析方法。样品经水、4%乙酸、10%乙醇、20%乙醇、50%乙醇、95%乙醇水基模拟物迁移后,过滤;样品经橄榄油、玉米油等油基模拟物、异辛烷化学替代溶剂迁移后,经甲醇/水(1:1,v/v)液-液萃取,过滤后,采用液相色谱-串联质谱在多反应监测(MRM)模式下检测,基质匹配标准曲线外标法定量。双酚S在5.0～80 μg?kg^-1范围内呈良好线性关系,相关系数(r²)大于0.9990;检出限(3S/N)为1.5 μg?kg^-1;按标准加入法进行回收试验,加标回收率在85.3%～108.0%,相对标准偏差(n=6)均小于5.0 %。     

QuEChERS-气相色谱–串联质谱法测定海南淡水鱼中有机氯农药残留

目的 以海南常见5种淡水鱼为研究对象,建立改良的QuEChERS方法结合气相色谱－串联质谱(GC-MS/MS)检测鱼肉中12种有机氯农药(OCPs)残留的快速检测方法。方法 样品采用丙酮+正己烷(1+1)超声提取,经0.4 g PSA、0.4 g C18、1.2 g无水硫酸镁和40 mg 二氧化锆净化,GC-MS/MS检测。结果 在1.6～40 ng/mL范围内线性良好,Ｒ_²≥0.9985;3个添加水平(n = 6)平均回收率在90.8%～121.6%范围内,RSD在1.3%～7.5%范围内;检出限在0.04～0.72 μg/kg之间,定量限在0.13～2.43 μg/kg之间。结论 该方法灵敏度高、快速、准确,能够满足鱼肉中多种OCPs的检测要求。QuEChERS与二氧化锆净化,结合GC-MS/MS可以应用于鱼肉中OCPs的快速检测。     

超高效液相色谱-串联质谱法测定普洱茶中赭曲霉毒素A

目的 建立超高效液相色谱-串联质谱对普洱茶中赭曲霉毒素A进行测定的分析方法。 方法 普洱茶样品采用乙腈/水(7:3,v/v)提取,PriboFast Multi-Toxin IAC免疫亲和净化柱净化,超高效液相色谱串联质谱进行测定分析,采用内标法定量。 结果 赭曲霉毒素A在浓度5.32-99.50μg.L_^-1范围内具有良好的线性关系,相关系数为0.9993,3个加标水平下的回收率为92.5%~95.6%, 相对标准偏差为2.18%~3.25%,检出限为0.10μg.kg_^-1。普洱茶样品中的赭曲霉毒素A均为未检出。 结论 普洱茶中复杂基质的存在对赭曲霉毒素A的测定有干扰,应采用免疫亲和净化柱净化处理,该方法具有较高的灵敏度及准确度,适用于普洱茶中赭曲霉毒素A的实际检测。     

分散固相萃取结合稳定同位素内标-气相色谱-串联质谱法快速测定牛奶中7种多溴二苯醚

目的 建立同时测定牛奶中7种多溴二苯醚(PBDEs)的分散固相萃取结合¹³C稳定同位素内标-气相色谱-串联质谱(GC-MS/MS)法。方法 样品添加¹³C₁₂同位素内标后,以1%乙酸乙腈提取,采用新型Z-Sep+C18为吸附剂净化,DB-5色谱柱(30 m×0.25 mm,0.25 μm)分离,选择电子轰击源(EI)多反应监测模式(MRM)气相色谱-串联质谱进行测定,基质匹配标准曲线同位素内标法定量。结果 7种PBDEs在0.500～100 ng/mL范围内均呈良好的线性关系,相关系数r均大于0.999;在0.1、1.0、10 μg/kg 3个加标水平下的平均回收率为89.7%～102.9%,相对标准偏差(n=6)为3.8%～8.3%;检出限和定量下限分别为2.4～9.8和7.5～30 ng/kg。结论 该方法简单、快速、重现性好、灵敏度高,可满足牛奶中7种多溴二苯醚的检测要求。     

QuEChERS-高效液相色谱-串联质谱法测定粮谷中啶磺草胺的残留

目的 建立了高效液相色谱-串联质谱法(HPLC-MS/MS)测定粮谷中啶磺草胺的分析方法。方法 样品经酸化乙腈(含0.5%(V/V)乙酸的乙腈)提取,优化的QuEChERS(400 mg C₁₈、400 mg无水硫酸镁)方法净化,净化液经离心后,直接过膜上机检测。HPLC-MS/MS方法以0.1%(V/V)甲酸水-乙腈为流动相,流速为0.3 mL/min梯度洗脱,采用C₁₈色谱柱进行分离,电喷雾正离子电离(ESI^₊),多反应监测(MRM)检测,基质匹配外标法定量。结果 在11种基质(大豆、大麦、大米、高粱、黑麦、苦荞、土壤、小麦粉、小麦、燕麦、玉米)中,啶磺草胺在0.001~0.03 μg/mL质量浓度与其对应的峰面积之间线性关系良好,R^₂均大于0.996,在0.005、0.01和0.05 mg/kg 3个添加水平下,啶磺草胺的平均回收率在90.3%~112.3%之间,相对标准偏差在1.1%~7.9%之间。结论 方法准确度、精密度和灵敏度均符合农药残留检测的要求。     

气相色谱-串联质谱法测定白酒中18种邻苯二甲酸酯

建立白酒中18种邻苯二甲酸酯(PAEs)的气相色谱-串联质谱(GC-MS/MS)测定方法。方法 样品中加入PAEs同位素内标,调整样品的酒精度,以甲苯萃取,采用GC-MS/MS以多反应监测模式(MRM)测定。结果 苯二甲酸二异壬酯(DINP)、邻苯二甲酸二异癸酯(DIDP)在0.1～10 μg/ml,其他16种PAEs在0.01～1.0 μg/ml范围内呈良好线性关系,r²≥0.991;方法检出限为3.1～150.0 μg/L,定量限为9.9～500.0 μg/L;在3个加标水平下,样品平均回收率为98.5%～119.8%,RSD为0.6%～15.6%。结论 本方法提高了白酒中PAEs检测的特异性,适合于白酒中多组分PAEs的同时检测。     

凝胶渗透色谱-高效液相色谱法测定火麻仁油中Δ9-四氢大麻酚含量

目的 建立使用凝胶渗透色谱(GPC)净化,高效液相色谱(HPLC)分析测定火麻仁油中Δ⁹-四氢大麻酚(Δ⁹-THC)的检测方法。方法 样品经环已烷和乙酸乙酯溶解,经GPC净化分离,再以Agilent Eclipse XDB-C₁₈色谱柱(150 mm×4.6 mm,3 μm)分离,以乙腈-水流动相洗脱,二级管阵列检测器分析,外标法定量。结果 该方法在0～500 μg/L浓度内,线性相关系数(r)＞0.999,方法检测限(LOD)为0.05 mg/kg,定量限(LOQ)为0.17 mg/kg。加标回收率在84.6%～101.8%之间,相对标准偏差为3.2%～4.7%(n=6)。在实际样品检测中,10种不同品牌的火麻仁油中Δ⁹-THC含量在0.40～5.82 mg/kg之间。结论 该方法稳定性好,灵敏度高,适用于火麻仁油样品中Δ⁹-THC的检测分析。     

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.