乳酸甲酯脱水体系中丙烯酸甲酯的气相色谱分析

用气相色谱测定了乳酸甲酯脱水体系中丙烯酸甲酯的含量。样品用乙醚稀释,改性聚乙二醇FFAP毛细管柱分离,经FID检测器检测,以丙烯酸乙酯为内标,采用内标标准曲线法定量,丙烯酸甲酯的线性范围为0~53 mg.L-1,相关系数为0.999 4,检出限为0.001 5 mg.L-1(S/N=2),样品的回收率为96.8%~99.0%,相对标准偏差为1.55%~3.12%(n=7)。     

气相色谱-质谱联用法测定调味品中苏丹红Ⅰ、Ⅱ色素

应用气相色谱-质谱联用方法的选择离子监测技术(GC-MS-SIM),测定了调味品辣椒粉和腌料中的苏丹红Ⅰ、Ⅱ色素。分别在0.58~18.9 mg.L-1及0.31~19.8 mg.L-1浓度范围内,方法具有良好的线性关系。样品的平均回收率为85.5%~95.4%(直接萃取法)及80.7%~88.1%(氧化铝柱净化法),RSD(n=5)为3.64%~7.14%。样品称量为5.0 g时,苏丹红Ⅰ、Ⅱ的检出限分别为0.005 8,0.007 6 mg.kg-1。     

熔化提取-毛细管气相色谱法测定乙二醇硬脂酸酯中乙二醇的残留量

提出了毛细管气相色谱法测定乙二醇硬脂酸酯中乙二醇残留量的方法。样品在50℃熔化,经甲醇超声浸提,以丙二醇为内标,采用HP-5毛细管色谱柱分离,用火焰离子化检测器测定。乙二醇的质量浓度在102.6~1 026.0 mg.L-1范围内呈线性,方法的检出限(3S/N)为30 mg.L-1。应用此方法分析乙二醇硬脂酸酯,回收率在93.7%~103.2%之间。     

反相高效液相色谱法测定不同产地布渣叶的3种水解黄酮苷元

提出了反相高效液相色谱法同时测定布渣叶的3种水解黄酮苷元槲皮素、山奈酚和异鼠李素的含量。采用Kromasil C18色谱柱(250 mm×4.6 mm,5μm),以甲醇-0.4%(体积分数)磷酸溶液为流动相梯度洗脱,在368 nm波长处,对布渣叶的水解液进行了色谱分离测定。结果表明:槲皮素的质量浓度在1.97~19.7 mg.L-1,山奈酚在2.02~20.2 mg.L-1,异鼠李素在2.11~21.1 mg.L-1时分别与其峰面积呈线性关系。槲皮素、山奈酚和异鼠李素的加标回收率分别为93.0%~99.6%,92.6%~99.8%,92.5%~99.5%,相对标准偏差(n=6)分别为2.48%,2.80%,3.17%。     

毛细管柱气相色谱法测定烟用香精中黄樟素和香豆素

烟用香精样品以甲醇超声提取,提取液经高速离心、0.45μm滤膜过滤后,供气相色谱测定。采用SE-54毛细管柱分离样品,经火焰离子化检测器(FID)检测,外标法定量。黄樟素和香豆素的质量浓度均在1.0~50.0 mg.L-1范围内与其色谱峰面积呈线性关系,方法的检出限(3S/N)分别为0.3,0.4 mg.L-1。黄樟素、香豆素的回收率分别在88.0%~94.7%和89.0%~94.0%之间;相对标准偏差(n=6)分别在0.8%~4.5%和1.2%~5.7%之间。     

人工神经网络光致发光法同时测定α-萘乙酸和吲哚-3-乙酸

研究了酸度、有机溶剂、重原子效应和共存物对α-萘乙酸(NAA)及吲哚-3-乙酸(IAA)光致发光性质的影响,建立了人工神经网络不经分离同时测定NAA和IAA的新方法。该法测定NAA和IAA的线性范围分别是0.012~0.24 mg.L-1和0.0034~0.068 mg.L-1(荧光)0、.18~1.8 mg.L-1和0.18~1.8 mg.L-1(燐光),检出限分别为0.0039 mg.L-1和0.0019 mg.L-1(荧光)0、.14 mg.L-1和0.13 mg.L-1(燐光)。方法用于合成样和水样测定,回收率在93%~109%之间,结果满意。     

顶空-气相色谱法测定伊班膦酸钠注射液中丙酮和乙醇残留量

采用顶空-气相色谱法测定伊班膦酸钠注射液中丙酮和乙醇的残留量。选择顶空平衡温度和时间分别为70℃和40min,用CP-WAX毛细管色谱柱(30m×0.25mm,0.25μm)分离,氢火焰离子化检测器检测。丙酮的质量浓度在0.05~120mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.015mg·L-1。乙醇的质量浓度在0.25~120mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.25mg·L-1。丙酮和乙醇的加标回收率分别在97.0%~112%和94.9%~112%之间。丙酮和乙醇的峰面积相对标准偏差(n=6)分别为2.2%和2.5%。     

气相色谱-质谱法测定地板材料中8种挥发性有机物质

应用气相色谱-质谱法测定了地板中甲苯、乙苯、邻二甲苯、间二甲苯、对二甲苯、苯乙烯、乙酸丁酯、正十一烷等8种挥发性有机物质的含量。地板样品(5g)用甲醇(15mL)超声提取20min,所得提取液用Rxi-5ms毛细管色谱柱分离,在选择离子监测模式下测定。8种挥发性有机物质的质量浓度(间二甲苯与对二甲苯合并计算)均在0.5~10.0mg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.05~1.0mg·L-1之间。加标回收率在98.0%~105%之间,测定值的相对标准偏差(n=5)在2.3%~6.6%之间。     

流动注射法同时测定海水中氨氮和磷酸盐

采用流动注射法同时测定海水中氨氮和磷酸盐的含量。在优化的试验条件下,氨氮和磷酸盐的线性范围分别为0.25 mg·L-1和0.30 mg·L-1以内,检出限(3S/N)分别为0.42μg·L-1和0.56μg·L-1。氨氮和磷酸盐加标回收率分别在85.0%~103%和86.7%~103%之间,测定值的相对标准偏差(n=6)分别在0.43%~5.3%和0~4.1%之间。方法用于分析标准物质,测定结果与分光光度法的结果一致。     

气相色谱法与高效液相色谱法测定琥珀酸索利那新原料药中的残留溶剂北大核心CSCD

建立了测定琥珀酸索利那新原料药中残留溶剂甲醇、乙醇、丙酮、叔丁醇、乙酸乙酯、正庚烷、石油醚、甲苯的气相色谱法和测定吡啶的高效液相色谱法。气相色谱法中以N,N-二甲基甲酰胺为溶剂,以TR-5毛细管柱为分离柱,采用氢火焰离子化检测器。高效液相色谱法中以AQC18色谱柱为分离柱,以50mmol·L-1磷酸氢二钠水溶液(含0.1%三乙胺,pH为7.6)-乙腈(1+1)为流动相,检测波长为254nm。9种溶剂的质量浓度在一定范围内呈线性,吡啶的检出限为0.01mg·L-1,其余8种溶剂的检出限在1.17~5.00 mg·L-1之间,加标回收率在86.3%~101%之间,相对标准偏差(n=6)在2.4%~6.3%之间。     

过硫酸铵-尿素引发丙烯酸甲酯与明胶接枝共聚

接枝共聚合反应;过硫酸铵-尿素引发丙烯酸甲酯与明胶接枝共聚     

Methylacrylate polymers with photochromic side chains containing heterocyclic sulfonamide substituted azobenzene

Methylacrylate monomers containing azobenzene groups with heterocyclic sulfonamide: sulfisomidyne (4-amino-N-[2,6-dimethylpyrimidyn-4-yl]benzenesulfonamide) and sulfamethoxazole (4-amino-N-[5-methylisoxazol-3-yl]benzenesulfonamide) substituents were synthesized. The monomers were used for preparation of homopolymers and copolymers with butyl 2-methylacrylate and 2-ethylhexyl acrylate. The materials obtained showed photochromic properties manifested by trans-cis isomerization of the side chain azobenzene fragments induced by illumination with unpolarized and polarized light. The decrease of the absorbance of the E(trans) form at ≈450 nm was observed and the materials tested were in form of thin films deposited onto glass.The isomerization of the polymers carried out during ellipsometric measurements showed the reversibility of the process in repeated illumination cycles with green laser light. The change of refractive index caused by illumination was in the range ≈0.005-0.008 as determined by ellipsometry.     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

Synthesis and structure of hydroxyisoxazolidines and derivatives of hydroxylamine and alkenals

The reactions of N-substituted hydroxylamines with alkenals serve as a method for the synthesis of the corresponding 2-substituted 3(5)-hydroxyisoxazolidines. The reaction pathway is determined by the nature of the substituent attached to the nitrogen atom. Ring-chain isomerism has been detected in these newly obtained compoundsTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1270–1276, September, 1987.     

四环素-铕与卵磷脂的相互作用及卵磷脂的测定

以四环素(TC)-Eu3 作为荧光探针,提出了新的荧光光度法测量卵磷脂(PC)。在pH 5.7的酸度条件下,扫描不同浓度的PC与TC-Eu3 的荧光光谱。通过优化实验条件,得到了测定PC的最佳条件。卵磷脂能使TC-Eu3 位于612 nm处的特征荧光显著增强且增强的荧光强度与PC的量成正比。测量的线性范围为4.0×10-7~1.4×10-5mol/L,检出限为3.9×10-8mol/L。该方法已用于实际样品的测定。     

红霉素9,11-亚胺醚和乙腈分子加合物的合成和晶体结构

通过控制红霉素A (E)肟的贝克曼重排反应条件合成了一种关键中间体红霉素9,11-亚胺醚, 该化合物可与乙腈形成稳定的分子加合物(摩尔比为1∶1), 未见文献报道. 阐述了该化合物的合成、晶体结构、晶体学数据和结构参数. 该化合物为无色透明晶体, 属单斜晶系, 空间群P2₁. 对该加合物和已知化合物红霉素6,9-亚胺醚晶体结构的对照解析, 有助于对重排反应机理、异构化机理和两异构体还原差异性的分析, 对重排反应和还原反应起到积极的指导作用.     

Sizes of atoms and ions and covalency of bonding in molecules and crystals

A new system of atomic radii for the elements up to barium inclusive is constructed. Values of the radii are chosen so as the dependence between the dissociation energy of diatomic homonuclear molecules and a depth of atom overlapping is monotonous, and the scatter of data is minimal. The depth of overlapping is calculated as a difference between the sum of atomic radii and an experimental interatomic distance. Conclusions are made that: the radii of free atoms and ions are determined by the value of the electron density equal to 0.01 au; they considerably change in molecules and crystals only as a result of the charge transfer from cation to anion; covalent bonding is well described by the overlapping of free atoms (ions), confined by the surface of the given radius, and its energy depends upon the depth of overlapping of valence electron densities of atoms. A method of overlapping atoms is proposed for the approximate estimation of ionic sizes and charges in bound systems.     

Ni(Ⅱ)和Zn(Ⅱ)的乙基黄原酸盐与吡啶碱配合物的合成及性质的研究

乙基黄原酸基的结构为:(简写为Exan,它是一个双齿配体,能和许多金属离子形成稳定配合物。 本文依据实验结果,对3种Ni(Ⅱ)和2种Zn(Ⅱ)的乙基黄原酸盐混合配合物的性质作一些系统的比较.应用红外光谱讨论这些混合配合物的C—O及C—S键振动频率位移;用热谱讨论它们的热稳定性及失重过程的变化;通过组成分析用电子光谱及磁学方     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

Synthesis and Characterization of Chloralose-Derived Thiosemicarbazones and Semicarbazones and Investigation of Their Antimicrobial Properties

Thiosemicarbazones(7–10)/semicarbazones(11–14) were synthesized in good yields via the condensation of α-gluco-, β-gluco-, galacto-, manno- chloralose derived 1,4-furanodialdoses (1-4) with thiosemicarbazide(5)/semicarbazide(6). The structures of all products were characterized by FTIR, NMR spectroscopic methods and elemental analysis. The compounds have been found to display moderate antimicrobial activity against Gram-positive, Gram-negative bacteria and antifungal activity against a Candida albicans. MIC values of the compounds range from 260 to 1510 μg/mL.