5-硝基间苯二甲酸甲酯工业品的高效液相色谱指纹图谱的建立

建立了5-硝基间苯二甲酸单甲酯和5-硝基间苯二甲酸二甲酯共享的高效液相色谱-紫外光谱的指纹图谱.在反相C18色谱柱上,以甲醇-水-0.1%高氯酸水溶液为流动相,对5-硝基间苯二甲酸单甲酯和5-硝基间苯二甲酸二甲酯及其相关杂质进行分离测定.通过运行大量样品,绘制具有共同特性的指纹图谱.根据待测样品色谱峰的保留时间、紫外光谱及其峰面积,与色谱指纹图谱进行分析对比,建立了工业品5-硝基间苯二甲酸单甲酯和5-硝基间苯二甲酸二甲酯质量控制的新方法.     

高效液相色谱法测定废水中水杨酸及相关物质的含量

采用高效液相色谱法，在苯基柱上，以甲醇-水-磷酸(40：60：1，V／V／V)溶液为流动相，285nm检测，测定了废水中水杨酸及相关物苯酚、对羟基苯甲酸和对羟基间苯二甲酸的含量。该方法简便、快速，用于实际样品测定，获得满意的结果。     

3种前处理方法处理婴幼儿配方奶粉中二十二碳六烯酸、花生四烯酸、亚油酸和α-亚麻酸的差异性

探讨了国家标准GB 5009.168-2016中乙酰氯-甲醇甲酯化法、酸水解酯化法和碱水解酯化法3种前处理手段处理婴幼儿配方奶粉中4种多不饱和脂肪酸(二十二碳六烯酸、花生四烯酸、亚油酸和α-亚麻酸)含量的差异性。乙酰氯-甲醇甲酯化法和酸水解酯化法明显优于碱水解酯化法。乙酰氯-甲醇甲酯化法中,样品的水解和脂肪的甲酯化同时进行并相互促进,使得脂肪的释放和甲酯化能够完全进行。通过对反应过程和添加回收率两个方面的考察,证明了乙酰氯-甲醇甲酯化法检测结果的准确性。酸、碱水解酯化法是分别利用酸、碱对样品进行水解,然后提取脂肪进行甲酯化。从水解效率、提取效率及甲酯化效率3个方面对酸、碱水解酯化法进行对比,结果表明,水解效率是影响酸、碱水解差异性的主要因素,酸水解法更适用于婴幼儿配方奶粉中不饱和脂肪酸的测定。通过对实际样品的检测,进一步验证了乙酰氯-甲醇甲酯化法和酸水解酯化法测定多不饱和脂肪酸的准确性,同时对其他食品中脂肪酸的测定具有较强的指导意义。     

高效液相色谱法测定中药润燥止痒胶囊中大黄素和大黄素甲醚

提出了高效液相色谱法测定润燥止痒胶囊中大黄素和大黄素甲醚含量的方法。样品经甲醇-盐酸(10+0.3)混合溶液加热提取水解30min,采用Hypersil ODS 2C18色谱柱为分离柱,以不同体积比混合的甲醇和磷酸(0.1+99.9)溶液为流动相进行梯度洗脱,检测波长为254nm。大黄素和大黄素甲醚的平均回收率分别为100.2%和99.7%。     

秸秆纤维素的一步快速提取和水解

研究了秸秆纤维素的一步快速提取方法, 在醋酸和硝酸溶液体系中, 选择10种不同的反应条件, 进行了提取条件优选, 然后对提取的纤维素样品分别进行了水解. 结果发现, 纤维素提取的最佳条件为120 ℃, 固液比为1∶25, 在体积分数为80%的醋酸和10%的硝酸混合溶液中反应20 min, 纤维素的产率为38%. 纤维素样品的水解实验发现, 在最佳条件下提取样品的葡萄糖含量都大于90%, 水解率达到94%. 13C NMR和FTIR分析结果表明, 纤维素的分子结构未被破坏, 但纤维素Ⅰβ含量较高, 木质素和半纤维素的去除率都很高, 表明此方法是比较理想的制备高纯度纤维素的方法.     

固相萃取-气相色谱/质谱法同时测定涂料中的8种有机锡

建立了一种固相萃取（SPE）前处理、气相色谱-质谱（GC-MS）法同时测定涂料中8种有机锡的方法。样品采用阳离子交换固相萃取小柱净化,最佳固相萃取条件为：固相萃取小柱分别用5mL甲醇、7mL洗脱液（氯化铵、甲醇、冰乙酸的混合溶液）预洗,10mL甲醇活化;将用甲醇稀释的涂料样品上样后,用5mL甲醇淋洗,抽干2min,7mL乙酸-氯化铵甲醇溶液（10：90,V／V）洗脱溶液洗脱。洗脱液用四乙基硼化钠溶液衍生后,气相色谱-质谱法进行定性定量分析。结果表明：以标准加入法计算回收率,在1.68％-16.84%添加范围内,平均回收率在85％-105％之间,相对标准偏差均小于12％。     

样品溶液基质对毛细管电泳分离的影响

用样品苯甲醇，苯甲醛和苯甲酸研究了样品溶液基质十二烷基硫酸钠，磷酸二氢钾－四硼酸钠和乙醇对毛细管电泳分离的影响。实验结果显示，随着样品溶液基质种类和浓度的变化，非离子型的苯甲醇和苯甲醛的毛细管电泳分离有相同的变化规律，离子型的苯甲酸有相反的变化规律。乙醇的添加导致了三个组份的区带扩张。     

高效液相色谱-质谱法测定燕窝中唾液酸

建立了高效液相色谱-质谱法测定燕窝中唾液酸(N-乙酰神经氨酸)的方法。燕窝样品用冰乙酸(1+1)溶液水解释放出来唾液酸,以V(甲醇):V(水)=50:50为流动相,Inertsil ODS-SP(5μm,4.6 mm×250 mm)色谱柱分离,用电喷雾电离源进行电离,采用负离子模式和选择离子模式检测。方法的检出限为0.10 mg/L,样品平均加标回收率为95.2%,RSD为1.1%。     

一种同时测定沉香中沉香四醇和苄基丙酮的方法

<正>申请公布号:CN106198791A申请公布日:2016.12.07申请人:中山出入境检验检疫局检验检疫技术中心摘要本发明公开了一种同时测定沉香中沉香四醇和苄基丙酮的方法。用甲醇超声处理待测样品并同时做空白溶液,用甲醇配制具有浓度梯度的混合标准工作溶液,其中沉香四醇的浓度范围为20~200μg/m L,苄基丙酮的浓度范围为0.5~5μg/m L,利用气相色谱–质谱联用仪对标准工作溶液、空白溶液和样品溶液进行分析检测,得到相关色谱图,以样     

对白酒中甲醇含量国标测定方法的改进

按酒卫生标准的标准分析方法,用光度法测定白酒中甲醇含量的标准曲线不甚理想,对草酸硫酸溶液加入量进行了一些改变,所得标准曲线较为理想,灵敏度和精密度都有提高.测定了一些白酒样品中的甲醇含量,结果令人满意.     

Acetone solubility and diffusivity in poly(ethylene terephthalate) modified with low levels of 2,6-naphthalene dicarboxylic acid,isophthalic acid,and 2,5-bis-(4-carboxyphenyl)-1,3,4-oxadiazole

A series of random copolyesters was prepared by replacing up to 10 wt.% of the dimethyl terephthalate (DMT) in poly(ethylene terephthalate) (PET) with dimethyl 2,6-naphthalene dicarboxylate (NDC), isophthalic acid (IPA), or 2,5-bis-(4-carboxyphenyl)-1,3,4-oxadiazole (ODCA). Solution cast films of the resulting copolymers were prepared and characterized. Modification of PET with NDC and ODCA led to copolymers with glass transition temperatures higher than that of PET, while modification with IPA decreased the glass transition temperature. Copolymerization decreased crystallinity levels in all cases. The acetone solubility and acetone diffusion coefficient were determined by integral kinetic gravimetric sorption experiments at 35°C and 5.4 cm Hg acetone pressure. PET containing low levels of NDC had lower amorphous phase acetone diffusivity and solubility than PET, while PET modified with IPA had amorphous phase acetone diffusivity and acetone solubility similar to that of PET. PET modified with 5% ODCA had amorphous phase acetone diffusivity similar to that of PET, while PET modified with 10% ODCA had an amorphous phase acetone diffusivity value slightly lower than that of PET. Copolymers containing ODCA had somewhat higher acetone solubilities that PET, due mainly to the lower levels of crystallinity in the ODCA-containing polymers than in PET.     

非晶聚对苯二甲酸乙二酯的制备与表征

通过单体酯交换法和聚 2 ,6 萘二甲酸乙二酯 (PEN)与低分子量PET酯交换的方法分别合成了一系列NPA/TPA/EG和IPA/TPA/EG共聚酯 .随着NPA或IPA单元含量的增加 ,等温结晶速度迅速降低 ,共聚物的结晶性降低甚至非晶化 .由NMR分析得知单体酯交换法与聚合物酯交换法得到的共聚酯NPA/TPA/EG序列分布相近 ,链结构都接近完全无规 .由DSC结果分析 ,随共聚单体含量的增加 ,熔点和熔融热降低 ,结晶度也随之降低 .当NPA或IPA含量达到 2 0 %时 ,可以得到非晶的共聚酯 (APET) .本文还对共聚物组成与结晶温度的关系进行了表征     

Crystal Structure of a Cu（Ⅱ） Coordination Polymer： [Cu（IP）（TBZH）]2n （TBZH = Thiabendazole,IP = Isophthalic Acid）

The structure of a copper（Ⅱ） polymer, [Cu（IP）（TBZH）]2n 1 （TBZH = thiabendazole, IP = isophthalic acid）, has been determined by X-ray crystallography and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. It crystallizes in the monoclinic system, space group P21/n with a = 11.76, b = 10.41, c = 14.08A^°, β = 104.80°, V= 1666.0（3）A^°^3, Z = 4, Mr= 428.90, Dc= 1.710 g/cm^3, F（000） = 868,μ = 1.468 mm^-1 and S = 1.001. The 2-D layered gridding architecture of 1 is constructed from isophthalic acid and binuclear copper atoms. Hydrogen bonds and aryl ring π-π stacking interactions in 1 contribute to a supramolecular structure.     

Regular Copolyamides. III. Preparation and Characterization of Regular Aliphatic/Aromatic Copolyoxamides

Regular aliphatic/aromatic copolyoxamides were prepared from diamine-oxamides and aromatic diacid chlorides by interfacial and solution polymerization. Solution polymerization in chloroform or dimethylacetamide is preferred for the preparation of large quantities of polymers but interfacial polymerization is most conveniently carried out for the preparation of polymers with high molecular weight. Aromatic diacid chlorides used included the diacid chlorides of terephthalic acid, isophthalic acid, 2,6-pyridinedicarboxylic acid, two isomeric naphthalene dicarboxylic acids, two cyclo-hexanedicarboxylic acid isomers, as well as 1,1-cyclobutane-dicarboxylic acid. Copolymers of diamine-oxamides with mixtures of acid chlorides of isophthalic and pyridine dicarboxylic acid and isophthalic acid/tetrachloroterephthalic acid have also been prepared. Most polymers are film-forming and are soluble in concentrated sulfuric acid, trifluoroacetic acid, and dimethylacetamide (containing several per cent LiCl). A number of these polymers gave dense or asymmetric membranes, particularly the polymers from ethylene diamine as the aliphatic diamine, particularly poly(iminoethyleneimino-oxalyliminoethyleneiminoisophthaloyl) (p-222I). Diamine oxamides with more than two amide groups in the molecules have been prepared, and in one case polymers with aromatic diacid chlorides have been prepared by interfacial polymerization. All regular aliphatic/aromatic copolyoxamides are high-melting and generally decompose above 350°C without melting. They can, however, be fabricated from solution into brittle fibers or into desalination membranes.     

Synthesis and characterisation of poly[2,2-(m-phenylene)-5,5-bibenzimidazole] as polymer electrolyte membrane for high temperature PEMFCs

Intermediate-high molecular weight poly[2,2-(m-phenylene)-5,5-bibenzimidazole] has been produced by mixing 3,3′,4,4′-tetraminobiphenyl and isophthalic acid in polyphosphoric acid as polycondensing agent and triphenyl phosphite as catalyst. Polymers with intrinsic viscosities close to 1 were measured in 97% sulphuric acid. Membranes were prepared by solution casting and subsequently immersed in phosphoric acid in order to gain ionic conductivity. These membranes were characterised by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analyses, methanol permeation and conductivity measurements. Levels of acid and water absorbed by the membranes were measured and the kinetic of this process was studied. Finally, doped membranes were tested in an actual fuel cell setup, obtaining also information about gases crossover from the open circuit potential. Acceptably reproducible molecular weights between 115,000 and 190,000 were obtained allowing the casting of mechanically stable membranes, which showed a great affinity towards phosphoric acid, high thermal stability, and a conductivity of 0.039 S/cm at 190 °C with the membrane equilibrated in saturated air at 60 °C. Open circuit potential of a PBI membrane was 0.99 V, close to those of commercial perfluorinated membranes. A H₂/O₂ fuel cell with dry gases was able to produce a maximum power output of 0.22 W/cm² at 175 °C.     

Synthesis and gas barrier characterization of poly(ethylene isophthalate)

Poly(ethylene isophthalate) (PEI) was synthesized for this research with essentially a condensation polymerization of isophthalic acid and ethylene glycol catalyzed by zinc acetate and antimony trioxide. Several samples were obtained, and their characteristics were observed and compared with poly(ethylene terephthalate) (PET). The synthesized PEI samples were chemically identified by ¹H NMR. Thermal analysis with differential scanning calorimetry (DSC) yielded results that indicate the samples were primarily amorphous, with a glass‐transition temperature of 55–60 °C. Molecular weights of these PEI samples were also obtained through intrinsic viscosity measurements (Mark–Houwink equation). Molecular weights varied with conditions of the polymerization, and the highest molecular weight achieved was 21,000 g/mol. Finally, the diffusion coefficient, solubility, and permeability of CO₂ gas in PEI were measured and found to be substantially lower than in PET, as anticipated from their isomeric chemical structures. This is because in PET the phenyl rings are substituted in the para (1,4) positions, which allows for their facile flipping, effectively permitting gases to pass through. However, the meta‐substituted phenyl rings in PEI do not permit such ring flipping, and thus PEI may be more suitable for barrier applications. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4247–4254, 2004     

以异烟酰胺吡啶基异酞酸为配体的二维铕配合物的合成、晶体结构和荧光性质

标题化合物{[Eu(L)(HL)]·2H₂O}_n是由Eu(NO₃)₃·6H₂O、5-异烟酰胺吡啶基异酞酸(H₂L)、经水热反应得到。采用元素分析、IR及X-射线衍射法对该配合物进行了表征。晶体结构测试表明：晶体属于单斜晶系,空间群P2₁/c,晶胞参数为：a=1.344 02(18) nm,b=1.377 50(18) nm,c=1.623 07(15) nm,β=115.820(8)°,V=2.704 9(6) nm³,Z=4,M_r=757.45,D_c=1.860 g·cm^-3,μ=2.396 mm^-1,F(000)=1 504,R_int=0.051 4,R₁=0.032 2,wR₂=0.089 1。配合物的中心铕离子是八配位稍变形的双帽三棱柱结构,5-异烟酰胺吡啶基异酞酸将配合物桥联成二维双层结构。     

Poly(ethylene terephthalate) copolymers containing 5‐tert‐butyl isophthalic units

Poly(ethylene terephthalate‐co‐5‐tert‐butyl isophthalate) copolymers, abbreviated as PET^tBI, with compositions ranging between 95/5 and 25/75, as well as the two parent homopolymers, PET and PE^tBI, were prepared from comonomer mixtures by a two‐step melt‐polycondensation. Polymer intrinsic viscosities varied from 0.4 to 0.7 dL g^?1 with weight‐average molecular weights ranging between 31,000 and 80,000. The copolymers were found to have a random microstructure with a composition according to that used in the corresponding feed. The melting temperature and crystallinity of PET^tBI decreased with the content in 5‐tert‐butyl isophthalic units, whereas the glass‐transition temperature increased from 82 °C for PET up to 99 °C for PE^tBI. Copolymerization slightly improved the thermal stability of PET. Preliminary X‐ray diffraction studies revealed that PET^tBI adopt the same crystal structure as PET with the alkylated isophthalic units probably excluded from the crystal lattice. The homopolymer PE^tBI appeared to be a highly crystalline polymer taking up a crystal structure clearly different from that of PET and PET^tBI copolymers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 1994–2004, 2001     

Design and characterization of novel supramolecular liquid crystals involving multiple hydrogen bonds

A novel type of liquid crystalline system, namely 5-[4-(4-methoxyphenylazo)phenyloxyalkyloxy]isophthalic acidhydrazides (Dn, n = 3, 6, 10) was designed and synthesized. The FTIR spectra of the Dn compounds were examined in the range 4000-1000 cm^-1 at different temperatures. The results showed that the stretching vibration frequencies of the NH and C=O groups, and the NH₂ deformation shifted to lower frequencies with decrease of temperature, while out-of-plane NH bending shifted slightly to higher frequency. Intermolecular hydrogen bonding between NH, NH₂ and C=O groups is proposed and the schematic supramolecular Dn structure is given. This may explain the higher Dn transitional temperatures and their smectic phase behaviour compared with that of 5-[4-(4-methoxyphenylazo)phenyloxyalkyloxy]isophthalic acid diethyl esters.     

两类hcb网络构筑的三维柱层结构Ni(Ⅱ)基金属-有机框架化合物

在溶剂热合成体系中,5-羟基间苯二甲酸(H 2HIPA)和1,4-二(1氢-咪唑-1-基)苯(1,4-DIB)与Ni(Ⅱ)离子反应得到一个结构新颖的化合物Ni[(HIPA)(1,4-DIB)](1,CCDC:2034033)。单晶结构分析揭示化合物1结晶于单斜的P21/c空间群。HIPA 2-和1,4-DIB分别被Ni(Ⅱ)离子连接在一起形成了两种具有hcb网络的二维结构,也就是Ni-HIPA和Ni-1,4-DIB层。这两类二维的层状结构进一步形成(3,6)-连接网络特征的三维柱层式框架。此外,在紫外-可见吸收光谱上化合物1在200-450和520-750nm范围内有两个强的吸收峰,依据Kubelka-Munk(KM)方法其带隙宽度为2.1V,具有半导体特征。化合物1的相纯度和热稳定性也通过粉末衍射和热失重分析测试予以确认。