美国开发出食品保质检测新装置

不久前，美国开发出一种全新的食品保质检测装置，该装置由传感器与传感器与扫描器构成。据悉，传感器的主要材料是铅，包装食品时，将它置于食品匣内。检测时，扫描器对食品发射的无线电波信号会使食品产生振动，同时发出乐谱波。乐谱波先反射到食品盒壁上，后传导给传感器，通过标准数据库标定振动程度、振动传导时间及乐谱波的传导速度，瞬间即可确定所检测食品发生变质的时间。     

食品中化学性有害物的质谱软电离裂解规律及筛查技术研究进展

食品中化学性有害物是导致食品安全问题的重要原因，质谱是对食品中化学性有害物进行定性定量分析的有效方法。该文按照化合物结构类别，综述了食品中重要化学性有害物的质谱软电离裂解机理，包括农药、兽药、真菌毒素，以及其他化学污染物。对于每类化合物，重点综述化合物质谱裂解产生的特征碎片、中性丢失等，以及这些质谱软电离裂解机理在食品中化学性有害物筛查及发现中的应用。研究化合物的质谱裂解机理可以帮助研究者对化合物进行结构解析和结构确证，为食品中同类结构新型化学性有害物的发掘提供理论依据。     

进口日本食品连续发现严重质量安全问题

不久前，从国家质量监督检验检疫总局获悉，浙江、辽宁、上海、湖北等地检验检疫部门陆续从进口日本食品中发现砷、铅、镉、过氧化值超标等严重的质量安全问题。国家质量监督检验检疫总局再次紧急通知，要求各地检验检疫部门对日本输华食品严格把关，坚决把问题食品挡在国门外，确保进出口食品安全。     

中国现有2314种食品添加剂均有检测方法

不久前，有媒体报道称“食品添加剂六成无法检测”，引起社会关注。卫生部有关部门负责人表示，该说法不够准确，和实际情况有出入。目前，中国现有的2314种食品添加剂均有相应的检测方法，对食品添加剂在食品中残留量的检测管理与发达国家基本一致。     

再生塑料食品袋有害健康

国家轻工业食品质量检测成都站人士提醒消费者和食品生产厂家，切莫用“垃圾塑料”食品袋包装食品，以免危害消费者健康。国家轻工业食品质量检测成都站人士指出，没作任何消毒处理的再生塑料已经过多次污染，会对食品造成再次污染，特别是油类食品，若用聚氯乙烯塑料袋(盒)包装，其有害物质会溶解到油脂中，对食品造成污染，从而影响     

铁(Ⅲ)-H2O2-溴百里酚蓝体系阻抑动力学光度法测定痕量EDTA

乙二胺四乙酸（EDTA）是一种食品添加剂，具有良好的抗菌活性，可以防止食品褐变，但同时对人体有害。有些食品中，尤其板栗罐头中添加EDTA以改善表观和防腐，许多国家都对食品中残留EDTA作了限量规定。我国每年都有大量罐头食品出口，     

高效液相色谱法测定食品中安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸

近年来，由于消费者对食品的安全性日益关注，食品中常用添加剂，特别是人工合成甜味剂[主要是糖精钠（SA）、乙酰磺胺酸钾（安赛蜜，AK）]和防腐剂[苯甲酸（BA）、山梨酸（SOR）、脱氢乙酸（DHA）]的使用情况越来越受到人们的重视，而GB2760《食品添加剂使用卫生标准》对其最高限量作了规定。目前，大多数分析方法只能测定上述物质中的二种或少数几种，能够同时测定上述五种食品添加剂的方法未见报道。     

加拿大、法国研制出新功能食品包装膜

加拿大一家公司研制出可测病原菌的食品包装膜，它利用以蛋白为基础的抗体来检测，该包装膜可以检测出沙门氏菌、大肠杆菌、李斯特菌等病原菌，当接触受到污染的食品时，即发生变色反应，从而确定有病菌污染，杜绝食品变质对人类的危害。法国向市场推出了两种使用普通聚氯乙烯(PVC)材料加工而成的新包装薄膜，用它可鉴定被包装食品是否使用转基因原料。     

食品室内实物标样的制作

对食品室内实物标样的定义、特点和应用进行了介绍，提出了食品室内实物标样的具体制作步骤和测试方法，并提供了室内实物标样制作和应用的实例。     

聚类分析法在食品TE分级中应用研究

用１５种食品的Ｚｎ、Ｃｕ、Ｆｅ、Ｍｇ含量作分级特征，按聚类分析分级，结果以Ｚｎ、Ｃｕ、Ｆｅ、Ｍｇ总量均值最低的蕃茄为Ⅰ级；低的白鸡、鲜牛奶、黄瓜、新会柑、罗岗橙为Ⅱ级；高的精面粉、水豆腐、粉丝、牛肉、鸡蛋、鸭蛋、西洋菜、白芽为Ⅲ级；最高的红豆为Ⅳ级．提示膳食中Ｚｎ、Ｃｕ、Ｆｅ、Ｍｇ含量大于供给量标准时可选Ⅲ、Ⅳ级，小于标准选Ⅰ、Ⅱ级，＝标准选Ⅰ、Ⅲ级食品．据此认为聚类分析法可用于食品分级，对选择食品、制订食谱、营养治疗、食品科研、研制食品配方等均具有实用价值和指导意义。     

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.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.