分散液相微萃取-液相色谱法测定奶瓶中的双酚A

建立了分散液相微萃取提取婴儿奶瓶中溶出痕量双酚A(BPA)的方法,并用高效液相色谱测定了其含量。奶瓶浸泡液用0.5 mL氯仿作萃取剂,0.5 mL甲醇作分散剂,以3 500 r/min离心10 min,吸取萃取剂20μL,进样,采用高效液相色谱法(HPLC)测定BPA的含量。色谱柱为Inertsil C18柱(5μm,4.6×150 mm),流动相为甲醇∶水(V∶V)=70∶30,流速为0.8 mL/min,检测波长为280 nm。该方法 BPA在0.05 mg/L~0.25 mg/L范围内线性关系良好(R=0.999 7),BPA检出限(S/N=3)为0.50μg/L。该法用于婴儿奶瓶中BPA含量的检测,测得婴儿奶瓶中双酚A的含量范围在0~18.93μg/L,平均加标回收率为96.44%,RSD为4.57%(n=4)。方法结果满意,可适用于婴儿奶瓶、矿泉水等食品和饮料容器中溶出BPA的含量测定。     

食品包装材料中双酚A和壬基苯酚迁移量检测方法的研究

采用高效液相色谱-荧光检测法,研究不用食品模拟物(水性、酸性、酒性、脂肪性)中双酚A和壬基苯酚迁移情况。建立了不同食品模拟物中目标物的前处理方法,各类型食品模拟物对应的标准溶液线性良好,相关系数达0.999以上,双酚A和壬基苯酚迁移测定检测的方法检出限分别为0.01 mg/kg、0.01 mg/kg(水性、酸性、脂肪性食品模拟物);0.05 mg/kg、0.05mg/kg(酒性食品模拟物)。采取升温加速试验,对样品中双酚A和壬基苯酚迁移量进行了检测,结果表明,双酚A和壬基苯酚更容易在50%乙醇和异辛烷(油脂替代物)为模拟物的情况下迁出。     

高效液相色谱法测定PC奶瓶中双酚A的含量及其迁移量

建立高效液相色谱法对PC奶瓶中残留双酚A(BPA)含量的检测方法,并以水为模拟液,固相萃取法富集处理,研究不同浸泡时间BPA的迁移变化规律。结果表明:市售某品牌PC奶瓶内可检测到BPA,其总残留量为10.7mg/kg;对PC奶瓶中残留BPA向水样中迁移的检测表明在1～6h内BPA迁移率为最大,6h后迁移量变化不明显,10h后基本到达饱和,整个过程中BPA的特定迁移量为0.36mg/kg,在水中的终质量浓度为0.025mg/L。该方法检测限(RSN=3)为0.6ng/mL,回收率在85.9%～89.5%之间,相对标准偏差0.78%～1.43%。     

免疫亲和柱-高效液相色谱法检测红曲米中的桔霉素

制备抗桔霉素(citrinin,CIT)单克隆抗体免疫亲和柱(IAC),建立了检测红曲米中CIT的免疫亲和柱-高效液相色谱检测方法。采用甲醇-水提取红曲米样品,将提取液用PBS稀释后过免疫亲和柱,甲醇洗脱后以高效液相色谱法检测,激发波长为331 nm,发射波长为500nm,流动相采用乙腈-磷酸溶液(体积比为45:55,pH2.0)。每根抗CIT单克隆抗体免疫亲和柱使用0.5 mL溴化氰活化的4FF琼脂糖凝胶,0.5mg桔霉素单克隆抗体,柱容量为0.35μg。红曲米样品添加CIT标品0.1～0.6 mg/kg,平均回收率为74.2%～87.14%,相对标准偏差为2.85%～13.12%。最低检出限为0.1mg/kg(S/N=3)。     

柱前衍生-固相萃取-高效液相色谱荧光法 测定蔬菜中草甘膦

目的建立快速、准确的蔬菜中草甘膦的柱前衍生-固相萃取-高效液相色谱荧光测定方法。方法蔬菜提取液样经衍生后经固相萃取,过C_(18)色谱柱,以甲醇-水(70:30,V:V)为流动相,流速1.0 mL/min,柱温为35℃,荧光检测激发波长为265 nm,发射波长为3 15 nm。结果草甘膦的加标回收率在89.2%~99.2%范围,其相对标准偏差均5.0%,在0.5~20.0 ng/mL范围呈现良好的线性,其回归系数0.999,最低定量检出限(LOQ)为0.02 mg/kg。结论本方法回收率高,净化效果好,杂质干扰少,可满足蔬菜中痕量草甘膦的残留检测要求。     

固相萃取-液相色谱法测定食品中脱氢乙酸

建立了固相萃取-高效液相色谱法测定食品中脱氢乙酸的方法。方法采用C18(5μm,4.6mm×250mmi.d)反向色谱柱,流动相:V(甲醇)∶V(0.02mol/L乙酸铵溶液)=7∶93,流速1.0mL/min,检测波长290nm,柱温30℃,进样量5μL。该方法的检出限在1.5～4.8mg/kg,线性范围0.01～0.08mg/mL,相对标准偏差(RSD)0.95%～2.10%(n=6),加标回收率94.5%～100.4%。该方法简单、快速、灵敏度高,并具有良好的精密度与准确度,可作为食品中检测脱氢乙酸的有效定量方法。     

固相分散萃取-高效液相色谱法测定郫县豆瓣中四种苏丹红染料的研究

建立了郫县豆瓣中苏丹红Ⅰ～Ⅳ的固相分散萃取(SPDE)-高效液相色谱(HPLC)分析方法。样品用无水硫酸钠作为分散剂,以乙腈提取样品中的苏丹红,提取液用中性氧化铝层析柱进行净化。用Inertsil ODS-sp C18柱(4.6mm×250mm,5μm))分离,流动相A为乙腈,流动相B为0.1%甲酸水溶液(A∶B为90∶10,V/V),等度洗脱,流速1mL/min,柱温40℃。二极管阵列检测器检测,检测波长为517nm,利用保留时间和光谱图定性,外标法定量。4种苏丹红染料在0.10～20.00μg/mL范围内线性关系良好,相关系数均大于0.9999,苏丹红Ⅰ～Ⅳ的检出限(LOD)分别为0.009～0.013mg/kg(信噪比S/N=3)。在添加浓度为0.5～10.0mg/kg范围内平均回收率达81.67%～93.28%,相对标准偏差(RSD)为1.07%～4.61%(n=6)。     

高效液相色谱法检测蔬菜中百菌清及其代谢产物的方法研究

建立了同时检测蔬菜中百菌清(CHT)及其代谢产物(4-羟基百菌清,CHT-OH)残留的高效液相色谱分析法。样品经丙酮提取,弗洛里硅土柱净化浓缩后以适量甲醇定容,HPLC紫外检测器检测,以C18色谱柱分离,甲醇∶水(90∶10,V/V)为流动相,流速为0.7mL/min,检测波长240nm。结果表明,百菌清、4-羟基百菌清的检测线性范围分别为0.05～10mg/kg和0.01～10mg/kg,相关系数r=0.9999。方法检出限分别为0.012mg/kg和0.005mg/kg,二者的平均加标回收率为83.5%～121.3%,RSD为2.4%～4.6%,该方法可用于市售蔬菜样品的测定。     

鸡肉中8种喹诺酮药物残留的高效液相色谱分析研究

建立了氧氟沙星(OF)、诺氟沙星(NF)、环丙沙星(HB)、达氟沙星(DF)、恩诺沙星(EN),二氟沙星(2F)、沙拉沙星(SA)、噁喹酸(OXL)8种喹诺酮类药物在鸡肉中残留的HPLC检测方法。流动相为0.1%三氟乙酸/三乙胺(pH3.0):甲醇:乙腈=82:12:6,勿需梯度洗脱,流速为1.0 mL/min使用双通道荧光检测器,检测波长为:A通道λex=280 nm,λem=480 nm,B通道λex=320 nm,λem=370 nm。方法的检出限氧氟沙星为0.0061 mg/kg、诺氟沙星为0.0036 mg/kg、环丙沙星为0.0046 mg/kg、达氟沙星为0.0012 mg/kg、恩诺沙星为0.0027 mg/kg、二氟沙星为0.0060 mg/kg、沙拉沙星为0.010 mg/kg、噁喹酸为0.012 mg/kg,各组分回收率在69.5%～110.5%,相对标准偏差为1.50%～6.73%。该方法简便、灵敏,可满足鸡肉中多种喹诺酮残留量的检测。     

高效液相色谱法测定饮料中的新红、诱惑红及赤藓红

利用高效液相色谱法测定饮料中的新红、诱惑红及赤藓红含量,确定了检测条件为:Agilent C_(18)(150 mm×4.6 mm,5μm)色谱柱,柱温25℃,流动相为乙酸铵-甲醇(92:8,V/V),流速1.0 mL/min,进样量10μL,检测波长254 nm。结果表明,新红、诱惑红及赤藓红在0~50μg/mL范围内线性关系良好(R~2=0.999 8),平均加样回收率为91.0%~96.8%,平均相对标准偏差(RSD)为0.4%~2.9%新红、诱惑红及赤藓红的检出限分别为0.10 mg/kg、1.00 mg/kg及0.70 mg/kg。该方法快速准确,适用于饮料中的新红、诱惑红及赤藓红含量的测定。     

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.