液相色谱法测定白酒中安赛蜜和糖精钠含量

建立了高效液相色谱测定白酒中安赛蜜、糖精钠的方法。采用在沸水浴条件下,将白酒样品50.0 g用旋转蒸发仪减压蒸发至近干后用水定容至10 mL,进液相色谱分析;用AQ-C18色谱柱（250×4.6 mm）,以0.02 mol/L的乙酸铵-甲醇（90∶10）为流动相,二极管阵列检测器在波长220 nm进行检测。结果表明,该方法的检出限低至安赛蜜0.014 mg/kg,糖精钠0.019 mg/kg,被测样品加标回收率：安赛蜜为97.5%,糖精钠102.0%。     

超高效液相色谱法测定白酒中乳酸的含量

建立了超高效液相色谱法测定白酒中的乳酸含量的方法。样品经40℃旋转蒸发除醇后稀释、过滤,Waters Acquity UPLC HSS T3色谱柱(100mm×2.1mm×1.8μm)分离,以0.02mol/L KH2PO4为流动相,流速:0.1m L/min,进样量:1μL,二极管阵列检测器,检测波长208nm。在100-1000mg/L范围内呈线性相关,相关系数R2为0.999。白酒样品中加标回收率为99.9-101.0%,重现性RSD=1.30%。     

两种氨基甲酸乙酯检测方法的比较及阜阳市售瓶装白酒中氨基甲酸乙酯含量调查

比较了液相色谱串联质谱法与固相萃取法检测白酒中氨基甲酸乙酯含量的差异,结果表明,两种检测方法均具有较低的检出限,线性均大于0.9999,且回收率好,但固相萃取法较液相色谱串联质谱法准确性更高,两种方法均可满足检测要求。采用液相色谱串联质谱法调查了阜阳市售瓶装白酒中氨基甲酸乙酯含量,白酒中氨基甲酸乙酯检出率为98.6%,氨基甲酸乙酯残留均值为81.9μg/L,73个样品中共有4个样品氨基甲酸乙酯含量超过了150μg/L,不同香型白酒中氨基甲酸乙酯含量差异较大。     

高效液相色谱串联质谱法测定白酒中甜蜜素的含量

目的 建立高效液相色谱串联质谱法检测白酒中甜蜜素的分析方法。方法 白酒样品经水浴加热后,用超纯水定容,经0.22μm水相过滤后,采用10 mmoL/L乙酸铵(A)和甲醇(B)作为流动相进行等度洗脱,采用高效液相色谱串联三重四极杆质谱仪测定白酒中甜蜜素含量。结果 甜蜜素在0.01～0.50μg/mL范围内线性关系良好(r~2=0.9999),检出限为0.015 mg/kg, 3个浓度下的加标回收率分别为96.18%、98.44%、92.69%,相对标准偏差为1.94%～2.11%。结论 该方法灵敏度高、回收率高、检测限低,适用于白酒中甜蜜素的检测。     

高效液相色谱蒸发光散射检测法测定乳制品中乳果糖

建立了高效液相色谱-蒸发光散射检测法测定乳制品中乳果糖的方法。通过调节样品溶液的p H值到1.7和4.5除去样品中蛋白质,采用氨基色谱柱,以乙腈-水为流动相梯度洗脱,用蒸发光散射检测器检测,在质量浓度为0.01~10.0 mg/m L内具有良好的线性关系,回收率在92.0%~103.5%,精密度(RSD)为2.98%~5.56%,检出限为0.04 mg/g。该方法可用于乳制品中乳果糖的日常监测。     

气相色谱法测定白酒中5种增塑剂的残留量

采用气相色谱法测定市售4种袋装白酒中5种邻苯二甲酸酯(DMP、DEP、DBP、DEHP、DnOP)的含量,建立快速、准确测定白酒样品中5种增塑剂含量的气相色谱方法。用正己烷液相萃取处理样品,结果表明:5种邻苯二甲酸酯线性范围均为0.01~2.50mg/L,相对标准偏差为1.064 7%~1.479 8%,加标回收率为95.93%~99.80%,说明该方法准确可信。4种市售塑料袋包装白酒样品均不同程度超出邻苯二甲酸酯类0.05mg/kg的检出限,表明邻苯二甲酸酯类污染物在白酒中有较大的迁移。     

超高效液相色谱法测定白酒中的琥珀酸的含量

建立了一种超高效液相色谱测定白酒中琥珀酸含量的方法。色谱柱为Waters UPLC C18,以pH为2.3的0.02mol/L KH_2PO_4为流动相,检测波长为210nm,流速为:0.2m L/min,进样量为:10μL。结果:该方法在5mg/L~200mg/L线性范围内相关,相关系数R 2为0.999,白酒样品平均加标回收率为:93.5%,R SD为1.17%。结论:该方法满足白酒中琥珀酸的测定要求,可为白酒中琥珀酸的测定提供参考。     

LC-ESI-MS/MS测定白酒中山梨糖醇的方法研究

建立使用液相色谱-质谱联用仪测定白酒中甜味剂山梨糖醇含量的分析方法。分析条件:分析柱为Agilent ZORBAX RX-C_(18),流动相为0.1%(体积分数)乙酸水溶液∶甲醇溶液体积比=20∶80,流速0.4 mL/min。结果表明,该方法在200～3200μg/L的范围内线性关系良好(相关系数r=0.998),检出限是40μg/L、定量限是200μg/L。样品中添加320μg/L和1600μg/L水平的山梨糖醇时,回收率在81%～105%范围内,相对偏差小于5%。该方法样品处理简单,其线性范围、相关性、灵敏度和精密度均符合白酒中山梨糖醇检测方法的要求,可用于检测白酒中山梨糖醇的分析。     

液相色谱串联质谱法同时测定白酒中4种甜味剂方法研究

用液相色谱串联质谱法同时测定白酒中甜蜜素、阿斯巴甜、糖精钠、安赛蜜4种人工合成甜味剂,排除了液相色谱、气相色谱等仪器测定时存在的假阳性的可能.样品只需简单前处理即可直接导入测定.采用多反应监测模式进行测定,4种人工合成甜味剂的回收率在86%～106%之间,定量检出限为5μg/L～12.5μg/L,在获得较高灵敏度的同时,大大缩短了样品检测周期,具有广阔的应用前景.     

LC-ESI-MS/MS测定白酒中甜味剂三氯蔗糖的方法研究

建立使用液相色谱-质谱联用仪测定白酒中甜味剂三氯蔗糖含量的分析方法。分析条件:分析柱为Agilent ZORBAX RX-C18,流动相0.02 mol/L乙酸铵水溶液(体积分数)∶甲醇溶液=30∶70,流速0.4 m L/min。结果表明,该方法在40～800μg/L的范围内线性关系良好(相关系数r=0.99999),检出限是40μg/L,定量限是100μg/L。样品中添加40～400μg/L水平的三氯蔗糖时,回收率在85%～105%范围内,相对偏差小于2%(n=12)。该方法样品处理简单,其线性范围、相关性、灵敏度和精密度均符合白酒中三氯蔗糖检测方法的要求,可用于检测白酒中三氯蔗糖的分析。     

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.     

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.