食用油中邻苯二甲酸酯类高通量检测方法的研究

建立固相萃取净化-气相色谱-质谱分析食用油中16种邻苯二甲酸酯的方法。样品用正己烷溶解,过SPE净化柱,采用气相色谱-质谱在选择离子检测(SIM)模式下进行定性、定量分析。结果表明:16种邻苯二甲酸酯在10～10 000μg/L范围内线性关系良好,平均加标回收率为70.0%～110.1%,相对标准偏差为2.68%～11.83%,检出限为10～15μg/L。     

GC-MS法测定食用油中邻苯二甲酸酯类物质的含量

监测日常桶装食用油中邻苯二甲酸酯类化合物的污染状况。样品经乙腈—正己烷溶解,SILICA/PSA玻璃混合型固相萃取柱净化,氮气吹干,正己烷定容,气相色谱—质谱(GC—MS)联用分析技术测定,外标法定量。方法检测的最低浓度为0.01 ng/g～0.1 ng/g之间,加标回收率为85.59%～112.98%之间,相对标准偏差在2.48%～12.07%之间。方法适用于食用油中邻苯二甲酸酯定性和定量测定。     

食用油中邻苯二甲酸酯的GC-MS测定方法研究

为了检测食用油中邻苯二甲酸酯污染程度,建立了气相色谱-质谱法检测食用油中邻苯二甲酸酯含量的方法.样品经环己烷-乙酸乙酯溶解,凝胶渗透色谱分离系统净化,减压浓缩至于,正己烷定容,气相色谱-质谱联用仪测定,外标法定量.在50μg/L～5000μg/L范围内具有良好的线性关系(R2＞0.997),方法检测限小于40μg/kg;在100μg/kg～5000μg/kg的添加水平下,邻苯二甲酸酯的加标回收率在77.52%～103.10%之间,相对标准偏差在0.29%～4.68%之间;方法精密度实验的相对标准偏差在5%之内;基质加标校正曲线的定量优于标准品校正曲线.结果表明,该方法适用于食用油中邻苯二甲酸酯定性和定量测定.     

气相色谱-串联质谱法高通量检测食用油中3类污染物

建立气相色谱-三重四极杆串联质谱同时测定食用油中的18种邻苯二甲酸酯、16种多环芳烃和7种多氯联苯的检测方法。样品经正己烷饱和乙腈超声提取、固相萃取柱净化,采用DB-5毛细管柱分离,以电子电离源,多反应离子监测模式定量测定。该方法邻苯二甲酸酯类塑化剂的线性范围为0.04～2 mg/kg,其中邻苯二甲酸二异壬酯的线性范围为1～40 mg/kg,多环芳烃和多氯联苯的线性范围为0.01～0.4 mg/kg,各物质在相应质量浓度范围内线性关系良好,相关系数均大于0.99。方法检出限范围为0.08～2μg/kg(除邻苯二甲酸二异壬酯的检出限为8μg/kg),回收率在62.7%～128.3%之间,相对标准偏差在1.1%～13.6%之间(n=6)。该方法准确、灵敏、简单、快速,可用于食用油中18种邻苯二甲酸酯、16种多环芳烃和7种多氯联苯的定量测定。     

食用油中5种邻苯二甲酸酯的液液萃取-固相萃取耦合富集和气质联用的测定

建立了食用油中常见的5种邻苯二甲酸酯(PAEs)类塑化剂的检测方法。食用油样品经乙腈提取后进行冷冻脱脂处理、玻璃ProElut PSA固相萃取柱净化,GC-MS全离子扫描定性、选择离子监测模式(SIM)定量。结果显示:食用油中5种PAEs加标回收率在76.17%~98.81%之间,相对标准偏差在1.01%~7.20%之间。该方法的仪器检出限(信噪比为3)和最低定量限分别在0.3~2.0μg/L及1.0~20.2μg/kg之间。该方法检测食用油中PAEs类塑化剂具有较高的准确度和灵敏度。     

同位素稀释-气相色谱-质谱法同时测定食用油中16种邻苯二甲酸酯类化合物

目的建立一种同位素稀释-气相色谱-质谱法(GC-MS)同时测定食用油中16种邻苯二甲酸酯类化合物含量的方法。方法样品经正己烷溶解,乙腈提取,经固相萃取柱净化,以GC-MS在选择离子监测模式(SIM)下测定,并采用同位素内标法定量分析。结果空白基质加标回收实验添加水平分别为500.0、1000.0、2500.0μg/kg时,大豆油中16种邻苯二甲酸酯的回收率在67.4%~110.5%之间,相对标准偏差在0.3%~12.7%之间;黄油中16种邻苯二甲酸酯的回收率在60.5%~108.3%之间,相对标准偏差在0.6%~12.7%之间。该方法在50.0~1000.0μg/kg浓度范围内线性关系良好,相关系数大于0.999,方法检出限为500.0μg/kg。结论该方法灵敏度、精密度和检出限均符合实际样品检测要求,适用于食用油中PAEs化合物的同时检测。     

全自动分子印迹固相萃取高效液相色谱法测定食用油中10种多环芳烃

为快速测定食用油中的多环芳烃,建立全自动分子印迹固相萃取高效液相色谱法测定食用油中10种多环芳烃的分析方法。将样品用正己烷溶解,以2 mL正己烷为淋洗液,二氯甲烷为洗脱剂,经全自动分子印迹固相萃取柱净化,氮吹后定容进高效液相色谱仪(配荧光检测器)检测。结果表明：所建方法线性关系良好,检出限为0.1～1.3μg/kg,定量限为0.3～4.0μg/kg;方法的准确度良好,精密度高,10种多环芳烃在玉米油和花生油基质中的加标回收率为79.2%～114.3%,相对标准偏差为0.4%～5.7%,将该方法应用于实际食用油样品中苯并[a]芘的测定,所测样品中苯并[a]芘含量均未超出国标限量。所建方法前处理简单快速,可实现固相萃取柱的自动化处理,减少有机溶剂的消耗,适合食用油中多环芳烃的快速测定。     

气相色谱-质谱法对食用油中17种邻苯二甲酸酯的测定

采用乙腈液-液萃取法对邻苯二甲酸酯类物质进行提取,通过弗洛里硅土固相萃取柱去除样品杂质,经旋转蒸干后定容,选择气相色谱-质谱联用技术进行测试,建立食用油中17种邻苯二甲酸酯的检测方法。该方法操作简单、准确可靠、重现性良好,各种邻苯二甲酸酯化合物的方法检出限为20～60μg/L,加标回收率为83.20%～102.09%,相对标准偏差为2.73%～5.77%,能够满足食用油中邻苯二甲酸酯类化合物含量的测定。     

凝胶渗透色谱-气相色谱-质谱法测定食用油中8种邻苯二甲酸酯类增塑剂

建立了凝胶渗透色谱-气相色谱-质谱法测定食用油中8种邻苯二甲酸酯类增塑剂的方法。采用凝胶渗透色谱(GPC)对食用油样品进行二次净化后进行气相色谱-质谱分析。结果表明:该方法的检出限在0.10~0.46μg/kg,定量限为0.35~1.52μg/kg,在2.38~9.52 mg/L范围内呈现良好的线性关系(R~20.99),加标回收率为89%~101%,相对标准偏差(RSD)在2.1%~7.7%之间。该方法可满足食用油中邻苯二甲酸酯类增塑剂的检测要求。     

气相色谱-质谱法检测食用油中的邻苯二甲酸酯

建立液-液萃取和固相萃取(SPE)提取方法,结合气相色谱-质谱(GC-MS)联用分析技术,检测食用油中的5种邻苯二甲酸酯类污染物的方法.该方法检测的最低浓度为10ng/g～20ng/g之间,回收率为75%～89%之间,并运用该方法对市售的塑料包装食用油进行了检测.     

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.     

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.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.