食品接触材料检测技术新进展

由食品接触材料中高关注物质迁移而导致的食品安全问题已成为当今社会的重点关注领域.这些有意添加物和非有意添加物具有种类复杂、无标准谱图和标准品等特点,使其识别鉴定、定量检测与安全评估面临着众多技术挑战.发展快速、准确、灵敏的食品接触材料检测技术,实现高关注迁移物的准确定量检测是食品接触材料安全研究和管理的关键.该文简要介...     

食品接触材料中化合物的非靶向筛查技术研究进展

近年来,食品接触材料中的化合物迁移作为食品安全风险的重要来源受到越来越多的关注,推动了分析技术的快速发展。传统的靶向筛查技术只关注部分有意添加物或少量非有意添加物,无法对可能存在的其他大量物质进行扫描和具体分析。而非靶向筛查技术则可以覆盖所有能检出的成分,能提供尽可能全面的迁移物信息和数据,从而为针对食品接触材料的风险评估、立法和风险管理工作提供科学支撑。但现今针对食品接触材料的非靶向筛查分析技术仍存在不少挑战。该文集中对食品接触材料中化合物的非靶向筛查技术进行综述,全面梳理和介绍了食品接触材料中化合物提取和定性分析技术的进展;重点讨论了在质谱分析中,质谱库特别是开放质谱库、高分辨率质谱、开源工具、与食品接触材料相关的化学结构数据库、保留时间指数和碰撞截面积预测模型等在食品接触材料组分鉴定中的潜在作用,以期为行业利用这些资源和工具开展食品接触材料组分的非靶向筛查工作提供参考。     

塑料食品接触材料样品前处理与检测技术研究进展

塑料食品接触材料是食品接触材料类别中最常见的一种材料,其本身可能含有的潜在化学危害物质在与食品接触过程中发生吸收、溶解、扩散等迁移行为,进而造成食品污染,危害食品质量安全。采用适宜的样品前处理和检测技术对迁移物进行鉴别分析是塑料食品接触材料安全所面临的巨大挑战。该文就塑料食品接触材料的样品前处理技术和仪器分析技术进行了综述,并展望了其发展趋势和应用前景,旨在为从事塑料食品接触材料质量安全研究和检测的技术人员提供技术参考。     

食品接触塑料材料中有害重金属迁移量测定方法综述

塑料在食品接触材料中占有重要地位,通过介绍食品接触塑料材料中重金属危害及来源,总结食品接触塑料材料中有害重金属安全限量,并对目前食品接触塑料材料中有害重金属的迁移测定方法进行综述。开发食品接触材料快速检测方法是今后研究的方向。     

微塑料在食品中的来源及其检测技术研究进展

为促进食品中微塑料的治理,该文从食品中微塑料的来源、提取和分析方法等方面展开了系统综述,并针对食品中微塑料的规范分析提出了相关建议。研究表明从食品原料到生产加工过程及食品包装材料,都可能成为食品中微塑料污染的潜在来源。消解法是食品中微塑料提取的主要方法。目前,对食品中微塑料进行鉴别以及定量的主流方法有目检法、傅里叶变换－红外光谱、拉曼光谱、扫描电子显微镜、热裂解/气相色谱－质谱联用法等。今后,建议开展食品中微塑料检测的标准方法研究,开发纳米级微塑料的光谱鉴别和定量技术。同时,面对食品中越来越严重的微塑料污染情况,应加强微塑料在食品生产过程中的溯源分析和控制技术研究,加快新型材料的开发速度。     

汽车用废弃塑料的再生利用现状与展望

汽车废弃塑料的再生利用及其产业化可以变废为宝,减少资源浪费和环境污染。本文综述了近年来汽车废弃塑料的分拣回收和再生利用技术的现状。发展高效的废弃塑料分拣设备和高附加值的再生制品是现今研究的重点。结合国内外的行业发展状况,探讨了我国在发展高附加值的再生制品、可循环利用塑料材料和建立再生塑料的质量安全标准上面临的挑战。     

超高效液相色谱/静电场轨道阱高分辨质谱法同时测定塑料食品接触材料中光稳定剂和抗氧化剂的特定迁移量

建立了超高效液相色谱/静电场轨道阱高分辨质谱同时测定塑料食品接触材料中多种光稳定剂和抗氧化剂特定迁移量的方法。采用30 g/L乙酸、体积分数分别为10%、20%、50%的乙醇和油类模拟物(异辛烷)这5种食品模拟物对塑料食品接触材料进行处理,对处理液进行超高效液相色谱/静电场轨道阱高分辨质谱分析,外标法定量。该方法测定的40种目标化合物在相应的范围内均具有良好的线性关系,相关系数均大于0.998,定量限为0.01~1.00μg/L。考察了上述5种食品模拟物中光稳定剂和抗氧化剂的特定迁移量,平均加标回收率为81.46%~94.53%,相对标准偏差为3.25%~9.99%。应用该方法对市售塑料食品接触材料进行了测定,结果在部分样品中检出了不同含量的光稳定剂和抗氧化剂。该方法灵敏度高,定量限低,满足塑料食品接触材料中光稳定剂和抗氧化剂特定迁移量的检测要求。     

欧盟发布塑料食品接触材料新法规

欧盟委员会于2011年1月15日在其官方公报上发布了塑料食品接触材料的新法规,对用于食品接触材料中的塑料材料提出了要求。新的法规包括一系列规定,并决定于2011年2月4日生效。最早的产品应用将于2011年5月1日开始。按照法规性质,欧盟并未强制要求成员国将其转化为国家法律。     

一次性塑料餐具中风险物质的筛查

研究筛查和识别了一次性餐具（餐盒、杯子和吸管）中向食品模拟物10%乙醇和化学替代溶剂95%乙醇迁移的物质种类,以评估迁移物及一次性塑料餐具的安全风险。采用10%乙醇或95%乙醇在特定迁移条件下浸泡样品,浓缩浸泡液,用气相色谱－质谱仪（GC－MS）测定浓缩液中的物质,通过比对质谱数据库并结合红外光谱仪得到的样品信息,推测迁移物结构,并通过对比对照品或三重四极杆质谱分析方式确认。利用Cramer规则预测识别迁移物的毒性,结合测定的迁移量判断迁移物安全风险。在测试样品中识别出19种迁移物,其中有意添加物包括聚乳酸树脂及共混树脂的合成原料、润滑剂、增塑剂等,非有意添加物包括聚酯及有机硅树脂中的低聚物和增塑剂、抗氧剂中的杂质或副产物等。聚丙烯材质餐具中迁出的物质种类较少,而聚乳酸材质餐具以及无机填充聚丙烯餐具中迁出的物质种类相对较多;多数迁移物在95%乙醇中迁移量高于在10%乙醇中迁移量。安全评估结果显示,在含油脂食品模拟物中,聚乳酸或无机填充聚丙烯餐具中环状硅氧烷等低聚物和抗氧剂副产物等非有意添加物的迁出危害需引起关注。     

欧盟明年执行与食品接触的塑料新法规

最近,从国家质检总局标准法规中心了解到,欧盟已决定将适用于若干类与食品接触的塑料的特定迁移限值过渡期延长,其中包括盖子垫圈中的若干类塑化剂。特定迁移限值是指材料与接触时迁移进入食品的限量。有关与食品接触的塑料及塑料产品的欧盟法规（经修订的第2002／72／EC号指令）将禁止若干类材料与食品接触,并批准使用多类其它材料。获批准的材料须符合特定的使用条件及特定迁移限值。     

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.     

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.