基于超高效液相色谱-四极杆/静电场轨道阱高分辨质谱技术研究全氟化合物质谱裂解规律

目的 采用超高效液相色谱-四级杆/静电场轨道阱高分辨质谱研究全氟化合物的质谱裂解规律。方法 采用Thermo Hypersil GOLD aQ色谱柱（100 mm×2.1 mm，1.9 μm），以甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱，在电喷雾负离子模式下采集数据，采用全扫描和数据依赖的二级扫描模式，根据一、二级质谱离子的精确质荷比推导全氟化合物可能的裂解途径。 结果 全氟磺酸类化合物主要发生CC键和CS键断裂，产生特征碎片[·C3F6-SO3]- m/z 229.94和[SO3]- m/z 79.95；全氟羧酸类化合物首先丢失中性分子CO2，产生[M-O-CO2]-碎片离子，继而发生不同数量的CC键断裂，产生m/z 218.98、168.98、118.99等特征碎片离子。结论 该研究提出的质谱裂解规律对快速鉴定和分析复杂体系中全氟化合物具有重要作用。     

超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法探究大环内酯类质谱裂解规律

目的 采用超高效液相色谱-四级杆/静电场轨道阱高分辨质谱研究大环内酯类化合物的质谱裂解规律。方法 采用Waters ACQUITY UPLC BEH Shield RP 18(2.1×50 mm,1.7 μm)色谱柱,以甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱,在电喷雾正离子模式下采集数据,采用全扫描和数据依赖的二级扫描模式,根据一、二级质谱离子的精确质荷比推导大环内酯类化合物可能的裂解途径。11种大环内酯类抗生素主要发生糖苷键的断裂。结果 替米考星、吉他霉素、交沙霉素、泰乐菌素和螺旋霉素主要的特征离子碎片为m/z 174.11247、m/z 156.10191以及m/z 116.07060,同时丢失中性分子H2O。琥乙酰红霉素酯、竹桃霉素、泰利霉素、地红霉素、依托红霉素和克拉霉素主要的特征离子碎片为m/z 158.11756、m/z 116.10699以及m/z 98.09643,同时丢失中性分子H2O。结论 该研究提出的质谱裂解规律对快速鉴定和分析复杂体系中大环内酯类化合物具有重要作用。     

渔用麻醉剂MS-222的电子轰击电离质谱 裂解规律研究

目的建立气相色谱-串联质谱(GC-MS/MS)法研究渔用麻醉剂MS-222电子轰击电离的裂解途径的分析方法。方法针对MS-222,采用电荷和游离基理论,解释主要碎片离子的裂解机制。结果 MS-222经电子轰击电离产生特征碎片离子m/z 150、137、120和93;分子离子以饱和氧和不饱和氧为电荷/游离基中心引发α断裂和酯基上伴随γ重排的β断裂,碎片离子进一步发生简单α裂、消除反应等反应,产生相应的特征碎片离子。结论电子轰击电离结合GC-MS/MS可用于鱼类麻醉剂MS-222的质谱断裂机制研究,方法简便,可推广到其他鱼类麻醉剂的研究中去。     

高效液相色谱－串联质谱法测定减肥保健食品中非法添加药物苯佐卡因

建立了测定减肥保健食品中非法添加药物苯佐卡因的高效液相色谱-串联质谱分析方法。减肥咖啡、减肥茶、减肥胶囊、减肥片剂、减肥饼干等不同类型的减肥保健食品经超声萃取后,以WatersAtlantisT3柱(150mm×2.1mm,3μm)分离后,采用多反应监测(MRM)正离子模式检测,定性离子对为m/z166与m/z138和m/z166与m/z94,采用m/z166与m/z138进行定量。实验结果表明,苯佐卡因在0.01～50μg/L的范围内呈良好的线性关系,相关系数为0.9985,在低、中、高的3个添加水平范围内的平均回收率为69.3%～95.6%。同时研究了苯佐卡因的电喷雾电离质谱特征,推测其裂解途径。本方法灵敏度高,操作简便,可用于不同减肥保健食品中非法添加苯佐卡因的检测。     

面粉中三聚氰胺的高效液相色谱——质谱法测定

建立了面粉中三聚氰胺的高效液相色谱一质谱测定方法.色谱条件:Kromasil C18柱(4.6mm×250mm,5μm),流动相:乙腈-0.1%(体积分数)甲酸(体积比5:95),流速O.4mL/min.采用正离子模式的电喷雾质谱检测,以一级质谱得到的准分子离子m/z 127作为母离子,进行碰撞诱导解离二级质谱分析,选择母离子和MS的碎片离子m/z85、109定性确证,提取m/z85、109、127三个离子质量色谱峰面积定量.线性范围为0.01～0.5 mg/L,检出限0.01mg/L,回收率为80%～99%.     

面粉中三聚氰胺的高效液相色谱——质谱法测定

建立了面粉中三聚氰胺的高效液相色谱-质谱测定方法。色谱条件：Kromasil C18柱（4．6mm×250mm，5μm），流动相：乙腈-0．1％（体积分数）甲酸（体积比5：95），流速0．4mL／min。采用正离子模式的电喷雾质谱检测，以一级质谱得到的准分子离子m／z127作为母离子，进行碰撞诱导解离二级质谱分析，选择母离子和MS的碎片离子m／z85、109定性确证，提取m／z85、109、127三个离子质量色谱峰面积定量。线性范围为0．01-0．5mg／L，检出限0．01mg／L，回收率为80％～99％。     

亚麻酸异构体的气相色谱-质谱分析

本文采用气相色谱-质谱法对亚麻酸异构体的出峰顺序和质谱特征进行了分析研究。结果表明:脂肪酸在强极性毛细管柱BPX-70(120 m×0.25 mm×0.25μm)上的出峰顺序具有一定的规律性,所测亚麻酸异构体中,出峰顺序依次为C18:3 9t,12t,15t、C18:39c,12t,15t、C18:3 9t,12c,15t、C18:3 9t,12t,15c、C18:3 9c,12c,15t、C18:3 9c,12t,15c、C18:3 9t,12c,15c和C18:3 9c,12c,15c。根据断裂规律和质谱特征分析,α-亚麻酸甲酯和γ-亚麻酸甲酯的特征离子分别为m/z 79、108(ω离子)、236(α离子)、261、292和m/z 79、150(ω离子)、194(α离子)、261、292。在8种α-亚麻酸顺反异构体中,当12位双键为顺式时,基峰离子为m/z 79,并具有明显的ω离子(m/z 108)和α离子(m/z 236);而当12位双键为反式时,α离子消失,ω离子强度减弱,并表现出离子强度m/z107108,且同时当15位双键为反式时,基峰离子为m/z 95;而当15位双键为顺式时,基峰离子为m/z 67。双键位置和顺反构象对亚麻酸的质谱特征产生显著影响,且12位顺反异构的影响大于9位和15位的顺反异构。     

高效液相色谱串联质谱法测定肉制品中栀子黄色素

建立肉制品中栀子黄色素中藏花素和藏花酸残留的高效液相色谱串联质谱(HPLC-MS/MS)分析方法。实验优化了样品提取方法、液相色谱条件和质谱参数。样品用甲醇超声提取,乙腈饱和的正己烷脱脂,Eclipose plus C18色谱柱分离,流动相为乙腈-水溶液,流速1.0 m L/min。采用电喷雾质谱负离子模式电离,多重反应选择离子检测。藏花素的检测离子对为m/z 975.4/651.3和m/z 975.4/327.1,其中定量离子对为m/z 975.4/651.3,藏花酸的检测离子对为m/z 327.2/105.0和m/z 327.2/185.1,其中定量离子对为m/z 327.2/105.0。结果表明,线性范围50~2000 ng/m L,回收率为80.49%~90.34%,相对标准偏差3.01%,藏花素和藏花酸的仪器检出限分别为5、3 ng/m L,方法定量限分别为20、12 ng/m L,该方法简单、准确,适用于肉制品中栀子黄色素的定量检测。     

5种丁香酚类化合物的电喷雾质谱裂解规律研究

目的研究5种渔用麻醉剂的电喷雾质谱裂解规律。方法采用电喷雾离子源(ESI源),对丁香酚、甲基丁香酚、甲基异丁香酚、乙酰基异丁香酚和MS-222进行质谱分析。根据结构分为正、负2种离子检测方式(ESI~(+/-)),含有酚羟基团的丁香酚采用负离子检测方式,其余4种化合物采用正离子检测方式。结果在正、负离子检测模式下,5种渔用麻醉剂准分子离子分别为[M+H]~+和[M-H]~-。对准分子离子进行碰撞诱导解离(collision induced dissociation,CID),得到特征离子碎片。分析了5种化合物在相应离子模式下的电喷雾质谱裂解途径。结论本研究所提出的电喷雾质谱裂解规律,可为同类型分子结构的渔用麻醉剂的结构分析和鉴定研究提供了参考依据。     

气相色谱-质谱法分析北大西洋瓜参脑苷脂中2-羟基脂肪酸

通过酸甲酯化衍生、羟基乙酰化保护和二甲基二硫衍生方法对北大西洋瓜参脑苷脂中的2-羟基脂肪酸进行衍生,采用气相色谱-质谱技术分析其2-羟基脂肪酸组成。通过衍生处理和色谱优化,取得理想的色谱分析效果。根据质谱断裂规律,采用特征离子可对北大西洋瓜参脑苷脂中2-羟基脂肪酸上的羟基和双键位置进行准确判断,其中2-羟基饱和脂肪酸甲酯的特征离子为m/z 57(基峰离子),90,[M-59]+,[M-18]+和M+;2-羟基单烯脂肪酸甲酯的特征离子为m/z 55(基峰离子),90,[M-59]+,[M-18]+和M+。2-羟基单烯脂肪酸DMDS衍生物的特征离子为A+(m/z 75+14n)和B+(m/z 191+14m),根据这两个碎片离子即可快速准确推断2-羟基单烯脂肪酸中双键所处碳链位置。通过气相色谱-质谱分析,从北大西洋瓜参脑苷脂中共鉴定出9种2-羟基脂肪酸,以2-OH C24:1n-9(70.84%)、2-OH C23:1n-9(7.74%)和2-OH C20:0(6.82%)为主。     

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.