恩诺沙星时间分辨荧光免疫分析方法的建立

目的：采用时间分辨荧光免疫分析(time-resolved fluoroimmunoassay,TRFIA)技术建立高灵敏的恩诺沙星(enrofloxacin,ENR)快速检测方法。方法：以包被抗原(ENR-OVA)包被微孔板,与游离的恩诺沙星共同竞争抗恩诺沙星抗体,以铕(Eu3+)标记的羊抗兔抗体进行示踪。结果：方法的批内变异系数小于10%、批间变异系数小于15%,平均回收率为91.62%,灵敏度为5ng/L,可测范围为0.01～100μg/L,ED20、ED50和ED80分别为0.088、3.40μg/L和32.81μg/L。结论：ENR-TRFIA方法稳定性好、可测范围宽,具有很好的应用前景。     

液相色谱法快速测定鸡肉中氧氟沙星手性对映体残留量

建立了鸡肉样品中氧氟沙星对映体液相色谱荧光检测(liquid chromatography fluorescence detector,LC-FLD)残留量快速分析方法。鸡肉样品经磷酸盐缓冲液提取后,用C18固相萃取小柱净化,洗脱液吹干后用流动相复溶即可进行液相色谱分析。分析时采用LeapsilTM C18色谱柱,以水相(含2 mmol/L硫酸铜和2.5 mmol/L异亮氨酸,pH3.5)和甲醇作为流动相进行梯度分析,荧光检测器检测,其中激发波长为297 nm,发射波长为487 nm,外标法定量。本方法在5.0、50、100μg/kg和150μg/kg 4个添加水平下,左氧氟沙星对映体平均添加回收率在75.5%～86.1%之间,批内变异系数在1.97%～4.42%之间,批间变异系数在3.02%～6.02%之间;右氧氟沙星对映体平均添加回收率在77.3%～84.9%之间,批内变异系数在2.15%～4.21%之间,批间变异系数在3.87%～5.84%之间。方法对两种对映体的检测限均为1.5μg/kg,定量限均为5.0μg/kg。     

鸡蛋中环丙沙星、恩诺沙星残留物HPLC-MS/MS分析

目的建立鸡蛋中环丙沙星、恩诺沙星残留物液相色谱-串联质谱(LC-MS/MS)检测方法。方法鸡蛋中环丙沙星、恩诺沙星用酸性乙腈提取,正己烷除脂,采用Waters ACQUITY UPLC?BEH C18色谱柱(2.1mm×100mm,1.7μm)分离,电喷雾离子源在正离子模式下电离,多反应监测(MRM)模式扫描。结果环丙沙星和恩诺沙星分别在5.194～129.85 ng/ml和2.154～53.85 ng/ml范围内线性关系良好,线性方程分别为Y=1300X+17.7(r=0.9999)、Y=1450X-658(r=0.9993)。环丙沙星和恩诺沙星定量限(S/N=10)分别为1.0388μg/kg和0.4308μg/kg。分别添加环丙沙星含量为1.0388,2.597μg/kg,恩诺沙星含量为0.4308,1.077μg/kg的对照品溶液于阴性鸡蛋基质中,回收率分别90.7%～107.6%、80.1%～101.6%和85.0%～105.4%、86.9%～103.6%。结论该方法简单、灵敏、准确,可以作为鸡蛋中环丙沙星、恩诺沙星的检测方法之一。     

ELISA法与LC-MS/MS法测定动物组织中克仑特罗残留

目的:比较酶联免疫法(ELISA)和液相色谱-串联质谱法(LC-MS/MS)测定动物组织中克仑特罗残留量的准确度、精密度及检测限。方法:样品经过处理后,分别采用ELISA法和LC-MS/MS法进行测定;用ELISA法对组织样品进行初筛,测出阳性样品利用LC-MS/MS法进行确证。结果:应用ELISA法测定样品猪肉样品中克仑特罗的回收率为67.0%～99.6%,批内变异系数3.4%～8.7%,批间变异系数6.1%～9.6%,灵敏度为0.025μg/L,最低检测限0.025μg/kg;LC-MS/MS检测方法回收率88.62%～111.43%,批内变异系数4.4%～7.4%,最低检测限0.5μg/kg;用ELISA法对50份猪肉和50份猪肝样品进行检测,筛选出3个阳性样品,经LC-MS/MS确证为阳性,两种方法检测结果一致。结论:ELISA法灵敏度和准确度较高,样品处理方法简单,成本低,适合组织中克仑特罗残留大规模筛查;LC-MS/MS准确度高,适合于阳性样品精确定量。     

鲤鱼中恩诺/环丙沙星残留量的酶联免疫检测

应用酶联免疫分析方法定量测定鲤鱼中恩诺/环丙沙星残留量.测试曲线线性范围为10～810mg/kg,最低检测限为10μg/kg.向样品中分别添加20、100、500μg/kg三个浓度水平的恩诺沙星,平均回收率分别为80%、80.9%和76.6%.     

食品中赭曲霉毒素A三种检测方法的比较研究

本实验采用免疫亲和柱-高效液相色谱法、时间分辨荧光免疫层析法和酶联免疫吸附法分别对食品中的赭曲霉毒素A进行了测定,对其灵敏度、准确度、精密度和样品加标回收进行结果分析。结果表明:高效液相色谱法最低检出限为0.3μg/kg,变异系数为3.6%,平均加标回收率为98.7%;酶联免疫吸附法最低检出限为1.25μg/kg,变异系数为5.6%,平均加标回收率为102.3%;时间分辨荧光免疫层析法最低检出限为1.75μg/kg,变异系数为7.6%,平均加标回收率为94.7%。3种方法测定值无明显差异,均能满足样品检测的要求。     

基于QuEChERS前处理技术的水产品中喹诺酮类药物多残留ELISA检测方法的建立

建立了水产品中3种喹诺酮类(恩诺沙星、环丙沙星、氧氟沙星)兽药多残留的新型Qu ECh ERS前处理技术结合酶联免疫快速检测的分析方法。基本流程为样品经90%乙腈(1%乙酸)均质提取离心后,上清液依次用C18净化、静置沉淀蛋白后用于测定,该前处理方法灵敏、快速、经济、实用性强。测试曲线线性范围为0.107~177.896ng/m L,检出限为0.0087μg/kg,IC50值为4.34ng/m L。样品批内和批间平均回收率分别为94.10%、93.70%,批内变异系数为4.09%~8.41%,批间变异系数2.78%~7.99%。检测结果与HPLC的相关系数R2=0.9897,表明酶联免疫检测方法及样品前处理方法适合喹诺酮类药物多残留检测。     

四环素类药物时间分辨荧光层析检测试纸条的研制

本试验建立了一种检测四环素类药物的时间分辨荧光免疫层析技术,并在动物源性食品中对其检测性能进行了研究。实验结果显示,对猪肉、鸡肉等动物组织样品中四环素类药物的检测限为:四环素30μg/kg、金霉素60μg/kg、土霉素40μg/kg、强力霉素80μg/kg;对100ppb的磺胺二甲基嘧啶、恩诺沙星、氯霉素等药物无交叉反应,特异性较好;变异系数小于6%,精密度高;试纸条对高、低温不敏感,稳定性强。     

肉制品中喹诺酮残留检测

喹诺酮类药物是具有4-喹诺酮基本结构并且由人工合成的抗生素类药物,是一种人畜共用药,食用含有喹诺酮残留的食品会对人体造成危害。本实验参照GB/T 21312-2007,采用液相色谱-质谱/质谱法对羊肉中6种喹诺酮类药物的残留量进行检测。检测结果显示,环丙沙星、氧氟沙星、培氟沙星、诺氟沙星、恩诺沙星、洛美沙星检出限分别为0.06μg/kg、0.02μg/kg、0.07μg/kg、0.05μg/kg、0.06μg/kg、0.05μg/kg;回收率为84.1%～102.1%,各物质的精密度依次是10.5%、7.4%、8.5%、6.8%、6.9%、7.2%;空白对照值为零;本次实验所采集的12种羊肉样品均未检出环丙沙星、氧氟沙星、培氟沙星、诺氟沙星、恩诺沙星、洛美沙星这6种抗生素类药物,符合农业部标准。     

Fa PEx-LC/MSMS法测定茶叶中28种农药残留

本试验建立了茶叶中28种农药残留的FaPEx-LC/MSMS分析方法。样品经1%醋酸乙腈提取,FaPEx-tea固相萃取柱净化,用LC/MSMS检测分析。实验结果表明:28种农药在4～200 ng/mL范围内呈良好的线性,相关系数均在0.99以上检出限0.3～15.5μg/kg在2、6、20μg/kg三个不同浓度水平下,回收率在70.3%～130.1%,变异系数范围为1.9%～11.5%。此方法处理快捷、高效、环保,更适合批量样品快速分析。     

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.