3-氨基苯甲酸乙酯的电喷雾正离子质谱裂解规律

目的采用电喷雾电离串联质谱(ESI-MS/MS),对3-氨基苯甲酸乙酯在正离子模式下的裂解途径进行分析研究。方法通过ESI电离产生准分子离子[M+H]+,并对[M+H]+进行碰撞诱导解离(CID)获得3-氨基苯甲酸乙酯的二级质谱图。结果在CID模式下,3-氨基苯甲酸乙酯主要产生m/z 138、m/z 94和m/z 77三个碎片离子。通过解析3-氨基苯甲酸乙酯二级质谱图得到其裂解途径信息:3-氨基苯甲酸乙酯首先断裂苯环C1位支链上的乙氧基丢失一个乙烯生成特征碎片离子m/z 138,然后断裂苯环C1位支链上酯基丢失一个CO2生成特征碎片离子m/z 94,继续断裂C3位上C-N键丢失一个NH3并生成特征碎片离子m/z 77。结论 本研究所提出的3-氨基苯甲酸乙酯的电喷雾质谱裂解规律,为其在水产品体内代谢物质的鉴别提供参考依据。     

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。     

浅析三种渔用麻醉剂应用研究现状

MS-222、丁香酚类、2-苯氧乙醇是目前鱼类活体运输当中应用较为广泛的麻醉剂。为了更好了解这三种麻醉剂的特点、功效以及性价比,本文从麻醉剂性质、使用优缺点和应用研究状况等方面对MS-222、丁香酚类、2-苯氧乙醇进行了综述,并对目前我国使用和管理渔业麻醉剂存在问题提出建议,期望为今后规范使用渔用麻醉剂提供参考与借鉴。     

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。     

活体运输过程中冰片麻醉剂与MS-222对草鱼麻醉效果的对比研究

为提高水产品活体运输的存活率,文章探明了将传统中药冰片作为麻醉剂应用于水产品活体运输的可能性。对比了不同浓度的MS-222（间氨基苯甲酸乙酯甲磺酸盐,也称“鱼安定”）和冰片麻醉剂对草鱼(Ctenopharyngodon idellus)的麻醉效果,并在30 mg/L的冰片麻醉剂和20 mg/L的MS-222中研究了水温对麻醉效果的影响,最后在20 ℃水温条件下分别在30 mg/L的冰片麻醉剂和20 mg/L的MS-222中进行了麻醉模拟运输试验并对关键生化指标进行比较分析。麻醉试验结果表明：随麻醉剂浓度增加,草鱼进入相同麻醉期时间缩短,完全复苏时间延长,20~40 mg/L的冰片麻醉剂适于草鱼的麻醉运输。麻醉时间随水温降低而缩短,复苏时间随着水温降低而增加,20~25 ℃水温适于草鱼的冰片麻醉运输。麻醉模拟运输试验结果表明：冰片麻醉运输24 h存活率为100%,MS-222麻醉运输24 h存活率为70%。复苏时间随运输时间的增加而增加。冰片麻醉运输各项生化指标均优于MS-222麻醉运输。文章结果显示,在20~25 ℃水温条件下,冰片麻醉运输保活效果优于MS-222。     

二氧化碳麻醉对罗非鱼有水运输的影响

将麻醉剂应用于罗非鱼的有水运输能够减轻鱼类在运输过程中的应激反应,从而减少其氨氮排放,最终 达到延长运输时间的目的。本研究使用二氧化碳水溶液作为麻醉剂,并以化学麻醉剂间氨基苯甲酸乙酯甲磺酸盐 （MS-222）作为阳性对照,比较2 种麻醉方式的优劣。结果表明：罗非鱼在pH 6.2、9 mg/L二氧化碳麻醉液和质量 浓度为20 mg/L的MS-222麻醉液中存活时间最久,分别为548 min和710 min,且有水保活4 h后的复苏率均达100%; 罗非鱼在相同条件充氧清水中的存活时间仅为362 min,有水保活4 h后的复苏率为33%。因此,适宜质量浓度的二 氧化碳和MS-222麻醉液均能延长罗非鱼在有水保活过程中的存活时间。     

分散固相萃取-气相色谱-四极杆-飞行时间质谱法快速测定鲜鱼中的5种酚类麻醉剂

【目的】建立了以分散固相萃取技术为前处理手段,结合气相色谱-四极杆-飞行时间质谱(gas chromatography-quadrupole time of flight mass spectrometry, GC-Q-TOF/MS)测定鲜活鱼中5种酚类麻醉剂的快速分析方法。【方法】样品经乙酸乙酯提取后,氮气浓缩,复溶液使用C18和PSA混合粉末净化,GC-Q-TOF/MS测定。采用电子轰击离子源(electron impact ion source, EI)进行电离,选择离子对模式对目标母离子和子离子进行测定。【结果】5种酚类麻醉剂的基质曲线在5.0~500 μg/L范围内呈良好线性关系,相关系数r²均大于0.999,日内不同水平的加标回收率在3.58%~8.96%之间,相对标准偏差(RSD)为2.56%~5.28%。方法检出限(limits of detection, LOD)为3.58~8.96 μg/kg。【结论】该方法操作简单、回收率好、灵敏度高、重复性好,可满足鲜活鱼中酚类麻醉剂快速测定的要求。     

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。     

流通环节水产品及暂养水中孔雀石绿和麻醉剂 风险监测

目的对流通环节水产品及暂养水中孔雀石绿残留及丁香酚和间氨基苯甲酸乙酯甲磺酸盐(tricaine methanesulfonate,MS-222)2种麻醉剂残留进行监测,为水产品质量安全监管提供基础数据。方法采用国家标准和资料报道的检测方法,测定水产品及暂养水中孔雀石绿残留及丁香酚、MS-222麻醉剂残留。结果 48份流通环节水产品中,孔雀石绿及隐性孔雀石绿检出率为2.0%;丁香酚检出率为2.0%;所有水产品未检出MS-222残留。对应的48份水产品暂养水中未检出孔雀石绿残留及丁香酚、MS-222残留。结论本研究采集的流通环节的水产品的质量安全状况良好,可为相关部门完善水产品质量安全监管提供参考。     

ESI-Q-TOF-MS/MS用于碳青霉烯类抗生素及其中间体质谱裂解机理研究

采用电喷雾四极杆飞行时间串联质谱(ESI-Q-TOF-MS/MS),在正离子模式下,对美罗培南等碳青霉烯类抗生素及其合成中间体共8种化合物的裂解规律进行了探讨.实验结果显示碳青霉烯类抗生素在该质谱条件下易形成[M+H]+离子,其合成中间体则易观察到[M+Na]+离子.该8种化合物裂解途径相似,主要为分子内脱羧基反应、四元内酰胺环裂解反应及侧链结构中C—S键的裂解反应.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of     

The Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.     

National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the "13~(th) Five-Year Plan"

In Apri Commi major p Plan＂ （h 2014, the National Development and Reform ssion issued an announcement for selection of reliminary research projects for the ＂13th Five-Year ereafter referred to as ＂The Announcement＂）     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the latest scientific     

Contamination of animal feed and food from animal origin with mineral oil hydrocarbons

Oils and fats used for the production of animal feed can become contaminated with mineral oil material originating from gas oils (C₁₈-C₃₅) or synthetic oils (poly alpha olefins, C₂₅ to beyond C₄₅). An important cause is assumed to be the discharge of waste oils, such as motor oil and hydraulic oils. Mineral oil material was analysed by on-line LC-GC-FID directly in the fat or in a raw extract from animal feed or foodstuffs. In Switzerland in summer/autumn 1999 concentrations in oils and fats for feed production were often found to be between 100 and 1000mg/kg. In the feeds, the average concentration was around 100mg/kg with values ranging up to a maximum of 1000mg/kg; few samples were free of contamination. In animal body fat, the average concentration determined in summer 1999 was 25mg/kg, with a maximum of 150mg/kg, although in samples from December 1999, contamination was substantially lower. In the fat phase of eggs, the average concentration was 30mg/kg, with a maximum of 80mg/kg. Paraffin oil is used for feed production, which may account for part of the contamination problem (e.g. eggs).