超高效液相色谱-串联质谱法检测食用菌中荧光增白剂

目的建立新鲜食用菌中荧光增白剂85(fluorescent brightener VBL,VBL)、荧光增白剂71(fluorescent brightener CXT,CXT)和荧光增白剂113(blankophor BA,BA)的超高效液相色谱.串联质谱(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS,)定量检测方法。方法采用60%甲醇-水溶液,75℃水浴振荡提取试样中的荧光增白剂,经弱阴离子交换固相萃取柱净化,采用UPLC-MS/MS在负离子模式下检测,内标法定量。结果该方法在0.0100~0.500 mg/L范围内有良好的线性关系,相关系数r~20.990,在空白新鲜食用菌基质中,不同添加水平下方法的平均回收率范围为80.0%~101%,相对标准偏差为3.4%~11.9%;测定低限为0.100 mg/kg。结论此方法灵敏度高、准确、重现性好,适用于新鲜食用菌中荧光增白剂85、荧光增白剂71和荧光增白剂113的检测。     

薄层色谱原位富集显微拉曼检测荧光增白剂

利用薄层色谱(TLC)原位富集与显微拉曼光谱(micro-Raman)联用的方法对食品包装材料中荧光增白剂71(C.I.71)和113(C.I.113)进行检测。采用硅胶60F₂₅₄铝板为固定相,甲醇-乙酸乙酯-冰醋酸-水(0.6︰3.4︰0.5︰0.5)混合溶液为展开剂,在UV₂₅₄nm和UV₃₆₅nm下检测定位,用乙醇对薄层板上的目标斑点进行原位富集,在波长532nm条件下进行显微拉曼光谱micro-Raman检测,并对专属性、灵敏度进行考察。结果显示,C.I.71和C.I.113检测限分别为1.25 mg/kg和3.75 mg/kg,该法检测的7批食品包装材料一次性纸杯中,有2批含有C.I.113。所建立的方法专属性强、灵敏度高,可为食品包装材料中荧光增白剂的检测提供备选方法。     

UPLC-MS/MS法测定纺织品中6种荧光增白剂

建立了检测纺织品中6种荧光增白剂(FWA 85、FWA 28、FWA 351、FWA 71、FWA 52和FWA 135)的超高效液相色谱串联三重四极杆质谱(UPLC-MS/MS)分析方法。样品经60%甲醇水(体积比)超声提取,提取液经乙腈-5 mmol/L乙酸铵为流动相在C18色谱柱上梯度洗脱分离,在质谱的电喷雾正、负离子分段扫描和多反应监测(MRM)模式下测定。结果表明,6种待测物在各自线性范围内线性关系良好,相关系数均大于0.997;方法定量限(S/N=10)为0.02~4 mg/kg;3个添加水平的平均回收率在86.9%~103%;相对标准偏差(RSD,n=6)为3.0%~7.5%。实际样品检测结果表明,该方法具有前处理简单、结果准确等特点,适用于纺织品中6种荧光增白剂的同时测定和确证。     

高效液相色谱法分离测定湿巾中的荧光增白剂

建立高效液相色谱-二极管阵列检测法分离测定湿巾中三种荧光增白剂FWA 220、FWA 113和FWA71等物质的方法。采用Eclipse XDB-C18(4.6 mm×250 mm,5μm)色谱柱,流动相为乙腈-5 mol/L醋酸铵溶液进行梯度洗脱,检测波长为350 nm。实验结果表明,三种荧光增白剂在0.01~400.00 mg/L范围内具有良好的线性关系(相关系数均大于0.999 5),检出限和定量限分别在0.01~0.10 mg/L和0.5~5.0 mg/kg范围内。添加水平在10~800 mg/kg时,回收率范围为91.4%~102.2%,相对标准偏差(n=6)为1.6%~5.1%。该方法精密度高,重现性好,结果准确可靠,为荧光增白剂FWA220、FWA 113和FWA 71的质量评价提供了有效方法。     

昆明市市售纸巾荧光增白剂含量调查研究

本文的研究目的是了解昆明市市售纸巾中11种荧光增白剂的添加情况。调查方法为,从昆明市各超市、市场采集不同品牌的纸巾,采用超高效液相色谱法,经40%乙腈-水对纸巾进行超声提取,并洗脱分离、紫外检测,然后对检测结果进行分析。结果显示,昆明市市售各品牌纸巾中共检出9种荧光增白剂,阳性样品检出率达16.95%,其中C.I.71的检出率最高,为3.39%;C.I.113的平均值最高,为6.0mg/kg;C.I.85最高检出为38.6mg/kg;且同一样品存在检出多种荧光增白剂的现象。由此得出结论,昆明市市售纸巾中存在添加荧光增白剂的情况,为减少其对市民身体健康的危害,相关部门应该予以重视并加强监管。     

液相色谱-串联质谱法测定食品包装PE材料中荧光增白剂残留量

目的建立同时测定食品包装PE材料中荧光增白剂WS、PF、OB、EBF、EGM、KCB、KSN、OB-1等8种荧光增白剂含量的检测方法。方法采用液相色谱-串联质谱法建立食品包装PE材料中8种荧光增白剂同时测定方法。食品包装PE材料中的荧光增白剂经四氢呋喃和N,N-二甲基甲酰胺提取后,采用Discovery C_(18)柱(150 mm×4.6 mm, 5μm)色谱柱,以乙腈和5 mmol/L乙酸铵-甲酸溶液作为流动相,梯度洗脱,液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry, LC-MS/MS)电喷雾电离源,正离子多反应监测模式测定,外标法定量。结果本文建立的食品包装PE材料中8种荧光增白剂检测低限均可达到0.01 mg/kg;在0.01～6.25 mg/L浓度范围内相关系数均大于0.995,线性关系良好;在0.05、0.25、1.25 mg/kg 3个浓度水平加标回收,回收率在70.8%～99.6%之间;相对标准偏差在1.56%～9.66%之间。结论该方法净化效果好、灵敏度高,且快速简便,可应用于食品包装PE材料中荧光增白剂残留量的检测分析。     

酒店用纺织品中荧光增白剂的研究与分析

针对不同酒店档次、不同产品类别的300批次酒店用纺织品样本,以纺织品领域中常用的19种荧光增白剂为研究基础,采用高效液相色谱法研究样本中所含荧光增白剂种类、含量和来源。试验结果表明：94%的酒店用纺织品样本中含有荧光增白剂,其中使用频率最高的荧光增白剂有5种,分别是FWA71、FWA85、FWA351、FWA134以及FWA113,平均检出含量最高为800.82 mg/kg;中低端酒店荧光增白剂的检出率高于高端酒店,卫浴巾系列类产品荧光增白剂的检出率高于餐饮系列类和床上用品系列类产品;酒店用纺织品中荧光增白剂来源于生产过程中的后整理和清洗过程中的洗涤剂。     

HPLC-PAD外标法及UPLC-MS/MS内标法测定乳及乳制品中三聚氰胺的含量

分别建立高效液相色谱-二极管阵列法(HPLC-PAD)、超高压液相色谱-串联质谱法(UPLC-MS/MS)测定乳及乳制品中三聚氰胺含量的方法。利用HPLC-PAD外标法进行样品中三聚氰胺的初筛,利用UPLC-MS/MS法进行确证,以13C315N3-三聚氰胺为同位素内标定量。乳制品经乙腈、乙酸锌、盐酸溶液提取,质谱检测时,样品再经MCX固相萃取柱富集净化。HPLC-PAD法的定量限为4mg/kg,UPLC-MS/MS的定量限为0.05mg/kg;HPLC-PAD的添加回收率为95.7%～102.3%,UPLC-MS/MS的添加回收率为91.3%～95.7%(基质匹配曲线校正),两种方法的相对标准偏差(RSD)分别为1.98%～4.51%,1.60%～3.27%。     

UPLC-MS/MS与HPLC测定茶叶中10种氨基甲酸酯类农药残留的比较

比较了超高效液相色谱-串联质谱(UPLC-MS/MS)与高效液相色谱(HPLC)法测定茶叶中10种氨基甲酸酯类农药残留的分析方法。样品经乙腈提取,氨基固相萃取柱净化,HPLC和UPLC-MS/MS测定。结果表明,在相同的前处理条件下,两种方法均具有较好的准确度和精密度,UPLC-MS/MS法在0.01~0.1mg/kg添加水平下回收率为75.2%~115.6%,相对标准偏差(RSD)为4.4%~16.7%。HPLC法在0.05~1.0mg/kg添加水平下回收率为82.7%~120.7%,相对标准偏差(RSD)为0.8%~12.9%。UPLC-MS/MS法相对于HPLC法有更高的灵敏度,10种氨基甲酸酯类农药在UPLC-MS/MS上检出限为0.02~0.3μg/kg,HPLC法检出限为3~7.5μg/kg;其高灵敏度和选择性,使其更适于多农药残留同时检测和微量残留检测。     

超高效液相色谱-串联质谱法分析测定食用植物油中痕量δ9-四氢大麻酚

以电喷雾离子源(ESI)为电离源,在负离子采集模式下建立食用植物油中δ9四氢大麻酚(δ9-THC)超高效液相色谱-质谱/质谱(UPLC-MS/MS)检测方法。实验以甲醇为提取剂,经中性氧化铝固相萃取柱净化、Waters ACQUITYTM UPLC BEH-C18(2.1mm×100mm,1.7μm)色谱柱分离后以UPLC-MS/MS多反应监测模式进行分析。方法检出限和定量限分别为0.15μg/kg和0.45μg/kg。实验以δ9-氘代四氢大麻酚(δ9-THC-D3)为内标物,采用内标法定量。3个添加水平,平均回收率为68.0%～110.0%,相对标准偏差为8.8%～18.1%。本方法能够满足食用植物油中δ9-四氢大麻酚痕量检测的要求。     

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.