凝胶渗透色谱-高效液相色谱法测定蔬菜中 呋喃丹的含量

目的建立凝胶渗透色谱-高效液相色谱法检测蔬菜中的呋喃丹农药残留量。方法样品经乙腈提取和环己烷-乙酸乙酯溶解后,经凝胶渗透色谱净化和反相高效液相C_(18)色谱柱分离后,采用荧光检测器进行测定,荧光检测激发波长为285 nm,发射波长为320 nm,采用高效液相色谱法以外标法定量。结果呋喃丹在0.2~5.0 ng/mL浓度范围内呈良好线性关系,相关系数r大于0.999,检测限为0.01 mg/kg。对空白蔬菜样品进行呋喃丹3个浓度水平0.5、1.0和2.0 mg/kg的加标,回收率结果为78.3%~97.6%,相对标准偏差为3.26%~11.69%。结论本研究所建立的方法简单、灵敏度高,可适用于蔬菜中的呋喃丹农药残留的分析检测。     

高效液相色谱法检测鳗鱼组织中阿维菌素的残留量

建立了快速测定鳗鱼组织中阿维菌素残留量的反高效液相色谱测定方法.鳗鱼样品经乙腈提取,二氯甲烷进行液相萃取净化、浓缩,经N-甲基咪唑和三氟乙酸酐进行衍生化,高效液相色谱(荧光检测器)进行检测.本方法在鳗鱼组织中的阿维菌素残留量的最低检测限为1μg/kg;鳗鱼组织中添加浓度为2～20μg/kg时,阿维菌素的添加回收率在78.3%～101.9%.     

固相萃取-高效液相色谱法检测葡萄中氯吡脲的研究

利用固相萃取-高效液相色谱(SPE-HPLC)分离测定葡萄中氯吡脲的残留量。样品匀浆经乙腈提取,固相萃取柱净化后,在流动相为甲醇-纯水(体积比为63:37)、紫外检测波长为260nm的色谱条件下进行分离检测。实验结果表明:经筛选碱性氧化铝柱对样品的净化效果较好,氯吡脲在0.01～1.00μg/mL范围内线性关系良好,相关系数r=0.9999,最低检出浓度为0.0001mg/kg。试样在0.004、0.010、0.050mg/kg3个添加水平下的平均回收率在94.38%～99.33%之间,相对标准偏差(RSD)在1.67%~3.62%之间。利用此方法对市售4个品种葡萄中氯吡脲的残留量进行检测,最终残留均符合标准。     

固相萃取–液相色谱–荧光检测法测定半夏中 苯并[a]芘残留量

目的建立半夏样品中苯并[a]芘残留量的固相萃取-液相色谱-荧光检测法。方法样品用水浸泡后,用正己烷萃取,硅胶固相萃取柱和ENV固相萃取柱净化,分析时采用SUPELCOSILTM LC-PAH(25 cm×4.6 mm,5μm)色谱柱分离,以乙腈-水(85:15=V:V)为流动相,荧光检测激发波长384 nm,发射波长406 nm,外标法定量。结果苯并[a]芘的检出限为0.1μg/kg,在1.0~50.0 ng/m L浓度范围内,苯并[a]芘的线性相关系数为0.9999,线性关系良好,方法回收率在78.0%~102.5%范围内,相对标准偏差低于9.6%。结论该方法准确、实用、简便、快速,在中药材的苯并[a]芘残留量检测方面有广泛应用前景。     

超高效液相色谱法测定水果中咪鲜胺残留量

建立了水果中咪鲜胺残留量的超高效液相色谱(UPLC)检测方法。样品经乙腈提取,PCX固相萃取柱净化后,以甲醇-水(70∶30,V/V)为流动相,在流速1.0 m L/min条件下等度洗脱,检测波长为225 nm,用UPLC法快速测定水果中咪鲜胺残留量。在0~5.0μg/m L范围内,咪鲜胺的峰面积与其质量浓度呈线性相关,相关系数R≥0.999 7,在香蕉、苹果和柑橘中分别添加0.2 mg/kg、0.4 mg/kg、1.0 mg/kg 3个质量浓度的咪鲜胺标准品,回收率为93.00%~101.10%,精密度实验结果相对标准偏差(RSD)为0.219%,方法检出限为0.032 mg/kg。该方法能满足水果中咪鲜胺残留量检测要求。     

固相萃取-高效液相色谱-紫外检测法测定蔬菜中阿维菌素的残留量

目的建立固相萃取—高效液相色谱法-紫外检测法测定蔬菜中阿维菌素残留量的方法。方法选取本地区市售的6种蔬菜样品,经乙酸乙酯提取,经固相萃取柱净化后用甲醇定容。在C_(18)色谱柱上进行分离,以甲醇-水(9:1,体积比)为流动相,流速1.0 mL/min,检测波长为245 nm。结果在0.05～1.00μg/mL浓度范围内,方法线性关系良好,r~2值为0.9999,定量限为0.01 mg/kg。平均回收率为94.0%～98.0%,相对标准偏差不超过6%(n=6)。结论本方法前处理过程简便高效,样品检出限低,灵敏度较高,适用于蔬菜中阿维菌素残留量的检测。     

超高效液相色谱-紫外/荧光法检测蜂蜜中百里香酚含量

目的 建立超高效液相色谱-紫外检测法和超高效液相色谱-荧光检测法检测蜂蜜中百里香酚残留量。方法 试样用水溶解定容后,经0.22 μm滤膜过滤,液相色谱-紫外法和液相色谱-荧光法测定,外标法定量。液相分离采用C18色谱柱,流动相为乙腈-水(50：50,v/v),流速0.25 mL/min,进样量为2 μL。紫外检测波长为198 nm,荧光检测激发波长276 nm,发射波长298 nm。结果 紫外法和荧光法的定量限分别为2.0 mg/kg和0.2 mg/kg。在代表性洋槐蜜、油菜蜜、荆条蜜、枣花蜜和椴树蜜中,紫外法和荧光法添加回收率分别在93.6%～101.6%和97.9%～105.0% 范围内,相对标准偏差分别在0.3%～4.9% 和0.2%～2.8% 之间。结论 本文所建立分析方法具有操作简便、快速,准确度高的优点,满足方法学要求和国内外残留限量要求,适用于蜂蜜中百里香酚残留量的测定。     

超高效液相色谱法测定甘蓝和橙子中的阿维菌素残留

本文研究建立了甘蓝和橙子中阿维菌素农药残留的超高效液相色谱紫外(UPLC-UV)检测方法。样品经乙腈提取,混合使用乙二胺-N-丙基硅烷(PSA)和C_(18)基质分散净化剂进行净化,采用ACQUITY UPLC BEH C_(18)色谱柱(2.1×100 mm,1.7μm),以乙腈:水(V/V=70:30)为流动相,流速0.25 m L/min,柱温:35℃,紫外检测波长:245 nm。阿维菌素在甘蓝和橙子样品中存在程度不同的基质效应,故采用空白基质匹配的校准曲线外标法定量。结果表明,阿维菌素在0.25~10 mg/L范围内具有良好的线性关系,相关系数均大于0.9999。在0.05~0.5 mg/kg范围内,平均添加回收率为83.0%~100.2%,相对标准偏差为1.17%~1.30%。阿维菌素在甘蓝和橙子中的检出限(LOD)分别为0.0109和0.0160 mg/kg。该方法操作简单、准确、灵敏,可用于甘蓝和橙子中阿维菌素的分析。     

高效液相色谱紫外检测法测定猪肉中阿维菌素药物残留

建立了猪肉中阿维菌素残留的高效液相色谱测定方法。样品经乙腈超声波辅助提取、自制碱性氧化铝固相萃取小柱净化。以V(甲醇)∶V(水)=90∶10为流动相,245 nm波长检测,流速0.8mL/min。结果表明:本法测定的阿维菌素在7min内可以完全分离,线性范围为0.4mg/L~5.0mg/L,线性相关系数0.9998,当添加量为0.1、0.2、0.5mg/kg时,平均回收率为90.20%~100.58%,RSD为2.25%~6.68%。该方法具有快速、灵敏、准确的特点,适合猪肉中阿维菌素残留的测定。     

食品中甲醛残留量高通量检测方法研究

建立食品中甲醛残留量的高通量快速检测方法。样品中的甲醛在酸性条件下与2,4-二硝基苯肼发生加成反应,经高效液相色谱紫外检测器检测,流动相乙腈∶水(6∶4,体积比),流速1.0 m L/min,检测波长355 nm。该方法在0.05μg/m L~5.0μg/m L质量浓度范围内线性关系良好(R2=0.999 9),检出限为0.5 mg/kg,加标回收率为80.2%~107.7%。该方法操作简便、快速、实用性广,可为面粉、粉条、虾皮、竹笋、腐竹、鱼类(鱿鱼、鲫鱼等)、血豆腐等多种食品基质中甲醛残留量的检测提供参考。     

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.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.