高效液相色谱-串联质谱法测定双壳类水产品麻痹性贝类毒素

目的采用Supelco ENVI-Carb柱净化双壳类水产品中的麻痹性贝类毒素(PSP),建立高效液相色谱-串联质谱(HPLC-MS/MS)法检测双壳类水产品中的PSP,为水产品中的PSP检测提供方法依据。方法选用色谱柱TSK-GEL Amide-80(2.0 mm×250 mm,5μm),以2 mmol/L甲酸铵-50 mmol/L甲酸水和95%乙腈水(含2 mmol/L甲酸铵-50 mmol/L甲酸)为流动相,采用梯度洗脱进行分离。样品用1%乙酸溶液进行提取,上清液加入氨水后(pH=4.0)经Supelco ENVI-Carb柱净化,将洗脱液抽干收集,上机测定。多重反应监测(MRM)模式检测。结果PSP的线性范围为8.1~705.0μg/kg,检出限为10~35μg/kg,回收率在47.0%~91.3%之间。结论本方法提取效果好、基质效应小,适用于双壳类水产品中麻痹性贝类毒素的痕量检测。     

免疫亲和柱净化-高效液相色谱-三重四极杆质谱法测定双壳类水产中软骨藻酸

目的 采用免疫亲和柱净化双壳类水产中的软骨藻酸,建立高效液相色谱-三重四级杆质谱串联（LC-MS/MS）方法检测双壳类水产中的软骨藻酸,为水产品中的软骨毒素检测提供方法依据。方法 选用InfinityLab Poroshell 120 EC-C18色谱柱,以10 mmol/L甲酸铵-0.1%甲酸-甲醇为流动相,采用梯度洗脱进行分离。样品用80%甲醇水提取,上清液加入PBS缓冲液后经免疫亲和柱净化,将洗脱液氮吹至干定容后上机测定。多重态反应监测（MRM）方式检测。结果 软骨藻酸的线性范围为20.0~200 ng/ml,检出限为0.002 μg/g,回收率在75.2% ~ 85.7%之间。结论 本方法特异性强、提取效果好、无基质抑制效应,适用于双壳类水产中软骨藻酸的痕量检测。     

丝织物中酸性金黄G的液相色谱-质谱法测定

建立了固相萃取-超快速液相色谱-电喷雾串联三重四级质谱(SPE-UFLC-ESI-MS/MS)联用技术测定丝织物中的酸性金黄G。样品经SPE提取和净化后,采用ACQUITY UPLC BEH C18柱(100 mm×2.1 mm,1.7μm)色谱柱,乙腈(含0.1%甲酸)和水(含0.1%甲酸)为流动相进行梯度洗脱,电喷雾离子源电离,负离子多反应监测模式进行定性定量分析。酸性金黄G染料在0.5~100.0μg/L范围内线性良好,相关系数0.999 5,方法检出限为0.17μg/kg,回收率为97.2%~102.3%。     

液相色谱-串联质谱法测定豆类中左旋多巴

文章建立一种豆类中左旋多巴的液相色谱-串联质谱测定方法。样品经0.3 mol/L乙酸水溶液超声提取,Agilent Proshell 120 SB-C18(2.1 mm×150 mm,2.7μm)色谱柱分离,以0.1%甲酸水-甲醇为流动相进行梯度洗脱,多反应监测(MRM),内标法定量。结果表明,左旋多巴在0.1~5.0 mg/L范围内线性关系良好,相关系数为0.9994,检出限为1.5 mg/kg,定量限为5.2 mg/kg,方法的平均加标回收率为96.9%~105.5%,日内精密度和日间精密度均小于4%,具有操作简单、灵敏度高、准确度高、重现性好等特点,能够很好满足豆类中左旋多巴含量的检测需要。     

高效液相色谱-串联质谱法测定蜂王浆中红霉素及其代谢物

目的建立蜂王浆中红霉素A、红霉素A烯醇醚、脱水红霉素A和N-脱甲基红霉素A的高效液相色谱-串联质谱检测方法。方法以pH 6.0磷酸盐缓冲液为提取剂,经HLB小柱净化富集后,采用高效液相色谱-串联质谱仪分析。采用Agilent Polaris C18色谱柱(100 mm×2.0 mm,5μm),以甲醇和0.1%甲酸为流动相,质谱模式为电喷雾正离子监测。结果该方法前处理简单,线性范围为2.0~100μg/L,相关系数在0.99以上,四种化合物的检出限和定量限分别为0.5μg/kg和5.0μg/kg。方法采用内标法定量,回收率范围为70.0~118.1%,相对标准偏差小于10%。结论方法回收率稳定且重现性较好,能够满足日常检测工作的需要。     

HPLC法测定面制品中的姜黄色素

建立高效液相色谱法测定面制品中姜黄色素添加剂含量的方法,用甲醇∶水(7∶3,v/v)稀释并提取面饼样品中的三种姜黄素,采用Kinetex PFP五氟苯基柱(250 mm×4.6 mm,5μm)色谱柱,以0.1%甲酸水溶液和0.1%甲酸乙腈溶液为流动相,流速为1.0 m L/min,检测波长为420 nm,进样量为4μL。结果表明,三种姜黄素分别在1.0~100μg/m L范围内具有良好的线性关系,方法的定量限为10 mg/kg。实际样品检测发现,袋装方便面和咖喱味点心面的面饼中均检出姜黄素,总姜黄素含量均在50 mg/kg以内,符合GB 2760–2014的限量规定。     

超高效液相色谱-串联质谱法测定牛奶中23种兽药

建立超高效液相色谱-串联质谱测定牛奶中23种兽药残留的检测方法。用乙腈(含2%甲酸)提取牛奶样品中的目标化合物,经oasis PriMe HLB小柱净化后,氮气吹扫,用5%甲醇水溶液溶解残余物后分析。以水(含0.1%甲酸)-甲醇(含0.1%甲酸)为流动相,选择HSS T3色谱柱(2.1 mm×100 mm, 1.8μm)分离目标化合物,采用电喷雾电离串联三重四级杆质谱在多反应监测(MrM)模式下进行测定,外标法定量。23种兽药化合物的检出限为0.005～3.026μg/kg,定量限为0.1～10μg/kg,加标回收率为70.98%～118.63%,相对标准偏差为0.14%～11.55%,该方法简单快捷、准确可靠,可用于牛奶中23种兽药的检测。     

液相色谱-串联质谱法测定鸡肉中磺胺及其增效剂残留量

建立鸡肉中122种磺胺及1种增效剂多残留检测的液相色谱-串联质谱法。样品经过甲酸-乙腈(1:199,V/V)溶液提取,正己烷脱脂,液-液分配净化后,C_(18)柱分离,甲醇、甲酸-水(体积分数0.1%)为流动相梯度洗脱,采用电喷雾电离源(electrospray ionization,ESI)正离子多反应检测(multiple reaction monitoring,MRM)模式检测,外标法定量。结果表明:药物在2.0~100.0μg/L质量浓度范围内线性关系良好,相关系数均大于0.99,方法的检出限和定量限分别为0.5μg/kg和2.0μg/kg,在添加量为2.0、5.0、10.0μg/kg时回收率为61.8%~88.3%,相对标准偏差小于11.3%。该方法简便快捷,可用于鸡肉中磺胺类药物及其增效剂的多残留检测。     

超高效液相色谱-串联质谱法同时检测鸡肉中氯霉素、四环素、金霉素和土霉素

采用固相萃取法对鸡肉中氯霉素、四环素、金霉素和土霉素残留同时提取、净化、富集,并建立了用超高效液相色谱-串联质谱法对4种抗生素定性定量检测的分析方法。前处理部分采用含0.1%三氯乙酸的乙腈为提取溶剂,饱和了乙腈的正己烷溶液去除脂肪,超声波萃取2次;采用HLB固相萃取柱净化;色谱部分采用BEH C_(18)色谱柱(2.1 mm×50 mm,1.7μm),乙腈-0.2%甲酸水(含5 mmol/L乙酸铵)为流动相进行梯度洗脱。在最优条件下氯霉素、四环素、金霉素和土霉素在相应浓度范围内,线性良好,相关系数R2均大于0.999,其检出限分别为0.1、3.2、16.0、9.0μg/kg,日内、日间相对标准偏差(n=5)分别小于5.0%和10.0%,平均回收率为80.1%~92.5%。     

液相色谱-串联质谱法检测蜂蜜中15种喹诺酮类和17种磺胺类药物残留

目的建立同时测定蜂蜜中15种喹诺酮和17种磺胺类药物残留的液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)检测方法。方法样品经过磷酸盐缓冲溶液(pH=8)提取,过HLB(hydrophile-lipophile balance)固相萃取柱净化。以CORTECS C18色谱柱(2.1 mm×100 mm,1.6μm)分离,以5 mmol乙酸铵、0.1%甲酸水(A)和0.1%甲酸-乙腈(B)作为流动相进行梯度洗脱。质谱分析以电喷雾为离子源(electrospray ionization,ESI+),采用多反应监测(multiple reaction monitoring,MRM)。结果本方法在15 min内完成32种目标化合物的分离。15种喹诺酮和17种磺胺类药物在1.0、5.0和10.0μg/kg添加水平的回收率为54.9%~122.5%,相对标准偏差(relative standard deviation,RSD)小于18.7%(n=6),方法检出限为0.4μg/kg,定量限为1.0μg/kg。结论该方法快速、准确、灵敏,适合测定蜂蜜中喹诺酮和磺胺类药物残留。     

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.