基于脂肪酸差异的肉制品中猪源性成分鉴别方法的研究

建立了肉制品中脂肪酸的分析检测技术,通过分析脂肪酸含量、种类以及片段特征指纹图谱,实现了基于脂肪酸差异的肉制品中猪源性成分的鉴别。采用气相色谱法测定了大量肉制品,利用保留时间和质谱鉴定了36种脂肪酸成分,选取较为稳定的18种脂肪酸数据进行统计分析,确定不同油脂脂肪酸的差异,结合特征图谱,最终确定可用于鉴别猪源性成分的8种脂肪酸。该方法可用于确定肉制品中是否含有猪源性成分,方法简单、快速、成本低,辨别度较高,在猪源性成分鉴别中具有一定的应用前景。     

市场监管总局关于发布《食品中罗丹明B的测定》等3项食品补充检验方法

<正>近日,市场监督总局发布关于发布《食品中罗丹明B的测定》等3项食品补充检验方法的公告。公告指出,按照《食品补充检验方法工作规定》有关要求,《食品中罗丹明B的测定》《食用植物油中苯残留量的测定》《鳕鱼及其制品中裸盖鱼、油鱼和南极犬牙鱼源性成分检测》3项食品补充检验方法已经国家市场监督管理总局批准,现予发布。本次发布的3项食品检测方法涉及液相色谱法、液质联用法、顶空气相色谱法、实时荧光PCR检测等。其中《食品中罗丹明B的测定》主要规定了食     

植物源性食品中化学性危害物质的色谱-质谱检测技术研究进展

植物源性食品中的化学性危害物质威胁人们的健康和生命。现阶段植物源性食品中的化学性危害物质具有品类多、残留量低、存在未知潜在风险等特点,检测难度较大。因此,开发植物源性食品中化学性危害物质的高通量、高灵敏度的检测技术具有重要意义。色谱-质谱联用技术具有灵敏度高、选择性好、检测通量高等优点,在植物源性食品化学性危害物质的检测中得到了广泛应用。该文主要综述了色谱-质谱检测技术在植物源性食品化学性危害物质分析中的研究进展,包括植物源性食品中主要化学性危害物质的种类及检测概况、相关的样品前处理方法及发展趋势以及基于色谱-质谱的检测技术研究现状,探讨了不同检测技术的优势及存在的问题,并对其未来发展趋势进行了展望,以期为植物源性食品中化学性危害物质筛查研究提供参考。     

高效液相色谱/质谱法识别不同明胶酶解产物中特征多肽

在不同动物胶原蛋白序列比对基础上,利用高效液相色谱/质谱联用技术(HPLC/MS)建立一种通过特征多肽进行明胶鉴别的方法。实验以牛明胶和猪明胶为对象,序列比对结果表明,牛和猪的Ⅰ型胶原蛋白α1链和α2链均存在氨基酸序列差异。利用胰蛋白酶将牛明胶和猪明胶降解,通过HPLC/MS分析了两种明胶酶解产物中的多肽片段。结果表明:牛明胶和猪明胶酶解产物中均可检测出存在序列差异的特征性多肽,其氨基酸序列差异与两种胶原蛋白序列比对结果中的序列差异一致;酶解产物中特征多肽上的脯氨酸存在不同程度的羟基化修饰,特征多肽的相对含量主要受明胶分子量范围影响。利用HPLC/MS检测明胶酶解产物中的特征多肽是一种鉴别牛明胶和猪明胶的有效方法。     

基因检测技术在食品物种鉴定中的应用

食品安全关系国计民生,食品物种鉴定是食品安全链的重要环节。基因检测技术的发展使食品物种鉴定变得更加快速、准确、灵敏。本文对近十年来国内外采用基因检测技术进行食品物种鉴定的研究和应用情况进行了总结和分析,包括基因检测技术的特点、主要方法及其在动物源性食品、植物源性食品、高附加值食品和深加工食品分析中的应用以及未来的发展。     

超高效液相色谱-串联质谱法对饲料中15种β-肾上腺素能激动剂的测定

动物源性食品中兽药残留是近几年来国际社会开始研究的公共卫生问题之一.世界各国加强了对国际贸易动物源性食品中兽药残留的检测,而开展饲料及饲料添加剂中兽药残留的检测是从源头进行控制的有效手段[1].     

植物源性食品中多农药残留GC-MS高通量快速检测技术研究进展

植物源性食品基质复杂、农药种类繁多、农药残留限量标准严格,因此建立植物源性食品中多农药残留高通量快速检测技术十分重要。气相色谱-质谱联用（GC-MS）技术是多农药残留高通量检测领域应用最为广泛的一种技术。然而现阶段植物源性食品中多农药残留GC-MS高通量检测仍存在问题。国内外科研工作者对其进行了大量研究,在现有设备的基础上开发前处理新技术以及复杂信号高通量解析新算法是提高该检测水平的关键。该文对近年来国内外发展的基于GC-MS的植物源性食品中多农药残留高通量快速检测技术及相关文献进行了归纳和总结,重点从适合于不同种类农药提取的新型样品前处理技术、基于“数学分离”的复杂信号高通量解析新算法等方面阐述了植物源性食品中多农药残留高通量快速检测的最新进展,并对其存在的问题提出了相关建议,旨在为食品多农药残留高通量快速检测提供参考。     

动物源性食品大环内酯类抗生素残留检测样品前处理技术研究综述

大环内酯类抗生素在全球饲料添加剂中仅次于四环素类抗生素,使用广泛,可通过食物链进入人体,对人体健康造成影响.因此,开发相应的残留检测技术有重要的社会意义.而样品前处理技术的发展与革新对抗生素残留检测技术发展具有巨大的推动作用.本文综述了近年来动物源性食品大环内酯类抗生素残留检测样品前处理技术研究进展,并对样品前处理技术在动物源性食品大环内酯类抗生素残留检测中的应用前景进行了展望,以期为相关研究者提供技术参考.     

高效毛细管电泳在食品安全检测中的应用进展

近年来,食品安全问题频发,对人们的健康和社会发展造成了严重的危害,食品安全已成为人们关注的焦点问题之一。食品成分的复杂性、多样性对食品分析技术和方法提出了很高的要求。毛细管电泳(CE)由于分离模式多、分离效率高、分析速度快、试剂和样品用量少、对环境污染小等优点,在食品安全分析方面的应用日趋广泛。本综述对2009年以来CE在食品中非食用添加剂、农药残留、兽药残留、重金属离子污染、食品毒素以及食品包装材料中双酚A和塑化剂的检测方面的应用进行了总结,并对毛细管电泳在食品安全检测领域的主要发展方向进行了展望。共收录文献63篇。     

实时荧光聚合酶链式反应技术测定肉制品中犬源性成分

根据犬线粒体脱氧核糖核酸(DNA)序列设计了特异性引物和探针,应用实时荧光聚合酶链式反应技术,检测了肉制品中犬源性成分的含量。所提取的17种犬的DNA样品扩增后均能得到典型S形扩增曲线,而所选取的14种其他动物源的DNA样品均未呈现同样的扩增曲线;同一模板所得Ct值(n=7)的相对标准偏差为1.2%。这说明所设计的条件具有较好的特异性和重复性。犬源性组分DNA的质量分数在0.000 01%~10%内与其Ct值之间呈线性关系,检测的灵敏度为0.1pg,不同加工方法所得肉制品的扩增结果之间无显著差异。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.