GC-MS法测定白酒中邻苯二甲酸酯残留量

采用正己烷提取白酒中的16种邻苯二甲酸酯类增塑剂,建立了气相色谱-质谱联用法测定白酒中污染物邻苯二甲酸酯类增塑剂残留量的检测方法。该方法对白酒中16种邻苯二甲酸酯化合物的检测限为0.05 mg/kg,方法的检测浓度线性范围为0.5~5.0 mg/L,样品的加标回收率为80.0%~95.0%,测定结果的相对标准偏差为2.1%~7.0%(n=6)。该方法可以满足白酒中污染物邻苯二甲酸酯检测的需要。     

食品包装材料中邻苯二甲酸酯检测方法研究进展

介绍邻苯二甲酸酯的性质及其对人体的危害,综述了近几年来食品包装材料中邻苯二甲酸酯的检测方法及样品前处理方法,并对比了其优缺点。展望了食品包装材料中邻苯二甲酸酯分析方法的研究趋势。     

邻苯二甲酸酯类化合物检测方法研究进展

综述了2001～2010年来邻苯二甲酸酯类化合物的检测方法研究进展,讨论了包括光谱、色谱及色谱-质谱联用等各种方法在邻苯二甲酸酯类检测方面存在的优缺点,并提出了今后可能的发展方向(引用文献42篇)。     

离子迁移谱快速筛查白酒中痕量邻苯二甲酸酯的研究

建立了离子迁移谱技术快速检测白酒中痕量邻苯二甲酸酯的方法。对迁移管温度、进样口温度进行了参数优化后,选取5种典型的邻苯二甲酸酯进行了系统研究。在迁移管和进样口温度分别为90℃和160℃的条件下,邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯、邻苯二甲酸二异丁酯和邻苯二甲酸二(2-乙基己)酯的检出限分别为0.14,0.06,0.14,0.44和0.02 mg/L;9次平行测量的相对标准偏差RSD<8.9%,单个样品的分析周期小于95 s。将本方法应用于5种白酒盲样的检测,成功筛查出邻苯二甲酸酯类物质。利用离子阱质谱对5种邻苯二甲酸酯标样产物离子和白酒盲样的产物离子进行了确认,结果表明,离子迁移谱的谱峰是邻苯二甲酸酯离子。这说明丙酮作为掺杂剂,可以避免白酒中背景化合物的干扰。本方法适于大量白酒样品中邻苯二甲酸酯类物质的快速筛查。     

凝胶渗透色谱-气相色谱/质谱法同时测定食用油中22种邻苯二甲酸酯

建立了凝胶渗透色谱-气相色谱/质谱法同时测定食用油中22种邻苯二甲酸酯的方法。方法具有良好线性,相关系数R均大于0.999,检测限在0.09～11.83 mg/kg之间,平均回收率在81.45%～113.90%范围内,相对标准偏差为1.55%～9.41%。采用该方法对国内食用油中邻苯二甲酸酯增塑剂进行检测,实际样品中检出邻苯二甲酸二异丁酯、邻苯二甲酸二丁酯和邻苯二甲酸二(2-乙基)己酯,可满足目前食用油中邻苯二甲酸酯的检测要求。     

超声萃取-气相色谱-质谱法检测塑料玩具中8种邻苯二甲酸酯类增塑剂

建立了气相色谱-质谱法（GC-MS）同时测定玩具中8种邻苯二甲酸酯化合物的方法.利用四氢呋喃提取塑料玩具中邻苯二甲酸酯化合物,超声提取30 min,经乙腈沉淀,采用GC-MS外标法进行定量检测.结果表明,8种邻苯二甲酸酯线性范围为0.5~10 mg/L,相关系数均大于0.995,方法检出限为1.14~13.65 mg/kg,平均回收率为89.2%~103.8%,相对标准偏差为1.41%~4.93%.方法简单、快速、准确,可用于塑料玩具中邻苯二甲酸酯的检测.     

邻苯二甲酸酯的毒性及相关限制法规

自台湾"起云剂事件"爆发以来,邻苯二甲酸酯开始为人们所知。作为一种塑料助剂,邻苯二甲酸酯广泛应用于日常生活的各个领域,特别是食品包装领域。研究发现,邻苯二甲酸酯具有致突变性、致癌性和致畸性等毒性,会对人体及动物的肝、肾等造成损伤。由于邻苯二甲酸酯与塑料分子间的作用力较弱,容易从食品包装材料中迁移到食品中,世界各国都制定了相关政策对其使用进行限制;我国也制定了一系列政策和法规对其进行控制;今后研究新的检测方法和替代品将是解决我国目前邻苯二甲酸酯问题的主要出路。     

液相色谱法同步测定化妆品中6种邻苯二甲酸酯

采用甲醇超声提取,高效液相色谱-二极管阵列检测器(HPLC-DAD)同步测定化妆品中6种邻苯二甲酸酯类环境激素;探讨了流动相和色谱柱对6种邻苯二甲酸酯分离的影响,以及二极管阵列检测器对定性分析的重要性和检测波长的选择,并对实际样品进行了测定.结果表明:方法的线性相关系数R>0.999 8,检出限在4.0～10.0mg/kg,加标回收率为90%～98%,相对标准偏差为0.11%～1.13%.该方法灵敏、快速、高通量,可用于检测国际关注的6种邻苯二甲酸酯,为化妆品中邻苯二甲酸酯的测定提供参考依据.     

不同类别食品中21种邻苯二甲酸酯的气相色谱-质谱测定及其分布情况研究

首次建立了同时测定不同类别食品中21种邻苯二甲酸酯的气相色谱-质谱(GC-MS)分析方法.对各种类别的食品采取不同的分离、净化方法;优化了成分复杂的香精或植物提取物等样品的色谱测定条件,通过提取特征离子进行检测和确证,消除了基质干扰,避免产生假阳性结果;探讨了邻苯二甲酸酯类的质谱碎裂机理.21种邻苯二甲酸酯的质量浓度在...     

柱串联HPLC法测定塑料制品中的16种邻苯二甲酸酯

建立了用柱串联高效液相色谱系统同时检测塑料制品中16种邻苯二甲酸酯的方法。研究了流动相、梯度洗脱程序、色谱柱种类、前处理等条件对16种目标物分离的影响。在优化条件下,塑料制品经超声提取,氮吹浓缩后,用二极管阵列检测器进行检测,目标物在1～100 mg/L的浓度范围内线性良好,相关系数在0.9962～0.9999。16种邻苯二甲酸酯中DIDP的检测限为1.0 mg/kg,其余物质为0.08 mg/kg。3种不同添加水平,6次平行实验平均回收率为90%～130%,方法的精密度为0.59%～6.9%。适用于塑料制品中16种邻苯二甲酸酯的同时检测。     

Mass spectra of some oxadiazole derivatives

The mass spectra of some substituted oxadiazoles have been determined and analysed with the aid of high resolution mass spectrometry. Some characteristic and major differences between their spectra have been noted, and possible rationalizations have been advanced. The main fragmentation patterns of the 1,3,4-oxadiazole derivatives have been interpreted in terms of diazirine intermediates. Specific skeletal rearrangement processes have been observed in the spectra of the 1,3,4- and 1,2,4-oxadiazoles, and possible mechanisms are proposed.     

Self-association of sulfo derivatives of cobalt phthalocyanine in aqueous solution

Sulfo derivatives of cobalt phthalocyanine containing naphthalene fragments have been synthesized, and their self-association and molecular complexation with pyridine in aqueous solution have been studied by spectrophotometry. The dissociation constants of the dimeric associates have been determined. The effects of the number of functional groups in the peripheral substituents and of the axial ligand on the phthalocyanine dimerization process have been revealed.     

Physicochemical studies of octadecyl-trimethyl-ammonium bromide: a critical assessment of its solution behavior with reference to formation of micelle, and microemulsion with n-butanol and n-heptane

Octadecyl-trimethyl-ammonium bromide (C18TAB) is a much less studied representative in the alkyltrimethylammonium halide surfactant series. A comprehensive study of its normal and reverse micelle (microemulsion) formation has been herein conducted by the methods of conductometry, tensiometry, fluorimetry, and microcalorimetry. The energetics of its air/liquid interfacial adsorption and self-association in aqueous solution have been examined. The phase behavior of its combinations with water, n-butanol, and n-heptane in the formation of microemulsions have been investigated with identification of a variety of phases. The energetics of formation of water dispersion in oil (w/o) has been evaluated from dilution experiments conducted at different temperatures. From the results, structural parameters of the droplets have been determined at different [water]/[surfactant] mole ratios (omega) and temperatures. The w/o dispersions have evidenced both volume- and temperature-induced conductance percolation. The results have been treated in light of the Scaling equations, and the associated parameters for the process have been determined. The activation energies for the temperature-induced percolation process of the w/o dispersion have been evaluated and assessed.     

Kinetics of oxidation of some disaccharides in ammoniacal medium

Kinetics of oxidation of lactose, maltose, cellobiose and melibiose has been studied by hexacyanoferrate(III) in the presence of ammonia. A general mechanism involving the formation of intermediate enodiol anion has been suggested. The effects of dielectric constant and salts have been studied in detail. The oxidation products have been characterised by descending paper chromatography. Compensation effects have been observed.     

Development and in situ synthesis of monolithic stationary phases for electrochromatographic separations

Organic monolithic stationary phases have been synthesized in UV-transparent fused-silica capillaries, which have been used as test format of microfabricated device channels. The columns have been prepared by in situ polymerization of butyl acrylate, lauryl acrylate, 1,3-butanediol diacrylate, and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) in a ternary porogenic solvent. The resulting stationary phases have been tested in capillary electrochromatography and exhibited reversed-phase chromatography behavior toward neutral solutes. Van Deemter plots of phenylureas and polycyclic aromatic hydrocarbons, selected as model analytes, have been determined to study the influence of various polymerization and separation parameters on properties of the monoliths. The amount of AMPS and the nature of monomers in the polymerization solution have been thus adjusted. It has been observed that the ionic strength of the mobile phase may affect significantly the efficiency of the separation. The effect of the percentage of acetonitrile in the mobile phase on efficiency and permeability of the organic monoliths has also been investigated. Efficiencies greater than 300,000 plates/m have been obtained with the test compounds. Stability and reproducibility have been extensively studied.     

大气汽溶胶微粒子光学特性的研究

根据Mie微粒子光散射理论计算了汽溶胶大气模型的光学特性,得到了汽溶胶的散射截面、吸收截面和消光截面以及红外波段散射强度分布,同时计算了汽溶胶大气的发射率光谱,为研究大气红外传输提供了计算方法。     

A Plasma Surface Treatment of Polyester Textile Fabrics Used for Reinforcement of Car Tires

Polyester tire cord surfaces have been modified by plasma at low temperature and atmospheric pressure. The surface treatment has been executed by various nonequilibrium discharges, namely by barrier discharge, atmospheric pressure glow discharge and gliding arc. The polymeric multicord sewing threads treated by this procedure have been used in the same form as in industry, i.e., with the protecting oil films on their surface. The surface properties have been investigated by electron spin resonance spectroscopy and by measuring their contact angle with various liquids; partially the zeta potential measurements have been used, too. Further tests have been done at an industrial testing impregnation line using the common technology and conditions, on both plasma treated and untreated fibers. Finally, the standard H-tests and peel-tests have been used to characterize the fiber adhesion to usual testing rubbers.     

Ab initio molecular orbital calculations of the infrared spectra of hydrogen-bonded complexes of water,ammonia and hydroxylamine

Summary The geometries of three hydrogen-bonded dimers of hydroxylamine have been optimized, at the MP2 level of theory, using the 6-31G** basis set. These calculations yielded three separate local minima on the dimer potential energy surface. The interaction energies of these three species have been calculated, and corrected for basis set superposition error. The infrared band wavenumbers and intensities have been computed, and the monomer-dimer wavenumber shifts and intensity enhancements rationalized in terms of the types and strengths of hydrogen bonds present. The predicted wavenumbers have been correlated with those measured in a recent matrix isolation spectroscopic study, and an argument for the structure of the preferred dimer has been presented.     

Quantum-Chemical Study of the Oxidative Ability of Nitro Compounds Using Decomposition of Some Simple Amines in the Presence of Triplet Nitromethane as an Example

The photooxidation of amines with triplet nitromethane has been studied using the uB3LYP/6-311g* method. The activation energies for hydrogen atom abstraction from ammonia and the amino group of methylamine or aniline have been found to be 14.1, 4.9, and 6.3 kJ mol^?1, respectively. Details of the hydrogen atom transfer mechanism have been studied, the structures of transition complexes have been revealed, and noncovalent interaction energies have been evaluated in terms of the theory of atoms in molecules.     

卤代烷烃的交叉构象的计数

1969年,Derek Bardon和Odd Hassel由于在构象分析方面取得的成就获得诺贝尔化学奖,从此,构象研究十分活跃,随后,有机分子的交叉构象计数的研究也开始了（尽管此前已经有人做出过重要的工作）,发现烷烃的交叉构象数与其一些物理性质有关,如光谱,粘度等。