凝胶渗透色谱法测定甘蔗渣浆粕的分子量和分子量分布

本文介绍以丁酮为淋洗剂,用SN-OIA型G.P.C仪和Waters公司的聚苯乙烯标样(PS),得到标样和各试样的G.P.C谱图,并以一无线性回归法用TR-S-80微机处理数据,得到聚苯乙烯的校准曲线logM-V。(见方程)以相关系数接近I说明方程的可靠性;以丙酮为溶剂用水作沉淀剂分级甘蔗渣试样,然后按同理求出分级甘蔗渣浆粕的校准曲线logM—V.(见方程)和相关系数。根据方程和G.P.C谱图的各级分的高度,用微机直接打印出不同筛分浆粕的分子量及分子量分布。     

相对时间法计算凝胶渗透色谱测试大分子分子量和分子量分布

在凝胶渗透色谱(GPC)对大分子的分子量和分子量分布的测试中,本研究利用小分子乙二醇在系统中出峰时间恒定的现象,采用乙二醇的出峰时间作为标识物,将GPC的色谱图转化为相对时间,再以相对时间建立校正曲线,作为计算分子量和分子量分布的依据。此方法解决了在测试色谱图的记录、校准曲线的建立和分子量的计算中以实际时间来表示和计算分子量时,由于GPC泵的重复性不稳定、色谱柱柱效的下降、仪器更换过不同的色谱柱等因素造成的使校正曲线出现偏差、分子量计算结果出现误差等问题。     

水溶性凝胶渗透色谱法测定芸芝多糖组分的分子量及其相对含量

用水溶性凝胶渗透色谱法考察了芸芝多糖在水溶性凝胶柱上的吸附影响因素,建立了最佳分离的测试条件,成功地将芸芝多糖的混合物分离为３个组分,测得各组分的分子量分别为１,１９０,０００,７９６,００和５５２,０００;各组分相对百分含量分别为８３．６％,８．９％,７．５％。     

松香改性苯乙烯聚合物分子量及分子量分布的GPC测定

本文利用凝胶渗透色谱测定新型高分子材料（苯乙烯-歧化松香树脂乙烯酯）的分子量及分子量分布，实验数据重视性较好。标准偏差为0．074，变异系数为3．360％。     

高效凝胶渗透色谱法研究超氧化物歧化酶的分子量

本文采用凝胶渗透色谱仪，对修饰后的牛血ＳＯＤ进行测定。仪器：美国ＷａｔｅｒｓＡＬＣ／ＧＰＣ２４４型高效液相色谱仪，ＳｈｏｄｅｘＰ－８２葡聚精为高分子标样。采用紫外和示差折光双检测器进行测定。所得数据与经典的凝胶电泳法完全一致，为此类高分子材料的Ｍｎ、ＭＷ和Ｄ值的测定，建立了准确、快速的测定方法。     

高效凝胶渗透色谱法研究超氧化物歧化酶的分子量

 本文采用凝胶渗透色谱仪，对修饰后的牛血ＳＯＤ进行测定。仪器：美国ＷａｔｅｒｓＡＬＣ／ＧＰＣ２４４型高效液相色谱仪，ＳｈｏｄｅｘＰ－８２葡聚精为高分子标样。采用紫外和示差折光双检测器进行测定。所得数据与经典的凝胶电泳法完全一致，为此类高分子材料的Ｍｎ、ＭＷ和Ｄ值的测定，建立了准确、快速的测定方法。     

凝胶渗透色谱法测定聚丙烯腈共聚物分子量中宽分布校正法的应用

应用宽分布校正法对凝胶渗透色谱(GPC)进行了校正，将校正曲线用于聚丙烯腈(PAN)共聚物分子量的计算。对扣除色谱峰扩展效应前后的测试结果与乌氏粘度法测得的数据进行比较。结果表明，应用宽分布校正法时，必须扣除色谱峰扩展效应，才能得到较为准确的测试结果。     

凝胶渗透色谱法测定木素磺酸盐相对分子质量分布

1　引　　言用凝胶渗透色谱 (ＧＰＣ)测定木素磺酸盐相对分子质量和相对分子质量分布 ,国外早在 6 0年代起就有文献报道 ,但国内在这方面文献报道较少。本文使用示差折光和紫外检测器 ,分别获得木素磺酸钠和木素磺酸钙的色谱图 ,用激光光散射检测器和标定线两种方法计算样品的平均相对分子质量及相对分子质量分布 ,并探讨了影响结果的因素。2　实验部分2 .1　仪器与试剂　Ｓｐｅｃｔｒａ公司凝胶渗透色谱仪 ,配Ｐ10 0泵 ,ＴＳＫ ＧＥＬ柱 ,接ＤａｗｎＷｙａｔｔ公司ＤＳＰ多角度激光检测器(ＭＡＬＬＳ)和ＲＩ 15 0检测器 ;Ｗａｔｅｒｓ公司…     

凝胶色谱法测定木素磺酸盐电氧化降解产物的相对分子质量分布

 在Waters ALC/GPC244凝胶色谱仪上,使用Waters μ-Ultrahydrogel柱和示差折光检测器,以聚乙二醇作标样,测定了木素磺酸钙的电氧化降解产物的相对分子质量及相对分子质量分布。研究了流动相的电解质种类、离子强度和pH值对标样及试样色谱行为的影响。通过实验确定流动相为0.05 mol/L LiCl溶液,其pH值为6.5。所建立的方法用于木素降解产物相对分子质量分布的测定,具有简便、快速和稳定的特点。     

水溶性凝胶色谱测定碱木素和硫酸盐木素的相对分子质量分布

用凝胶色谱测定碱木素和硫酸盐木素相对分子质量分布,多在聚苯乙烯凝胶柱上,以四氢呋喃淋洗.因这两种木素在四氢呋喃中溶解度很小,故需经乙酰化处理.该过程会使木素相对分子质量发生变化,且较为繁琐.本文在Ultrahydrogel柱上用水溶性流动相淋洗,测定了桉木碱木素和桦木硫酸盐木素及其改性产物的相对分子质量及其分布.鉴于水溶性凝胶色谱中存在明显的非体积排除效应,本文探讨了影响测定结果的因素,并将测定结果与传统方法进行了比较.     

聚丙烯酸的凝胶渗透色谱分离及相对分子质量测定

采用Sepax Nanofilm SEC-150色谱柱和自制窄分布聚丙烯酸标样,考察了不同无机盐及其离子强度、酸度等对不同相对分子质量的聚丙烯酸分离效果的影响.在此基础上确定了凝胶渗透色谱分离聚丙烯酸的最佳条件:以磷酸盐缓冲液(离子强度0.10 mol/L,pH=6.9)为流动相,流速1.0 mL/min,柱温25 ℃...     

Analysis of Low Molecular Weight Polymers with Gel Permeation Chromatography

Intrinsic viscosities and gel permeation chromatography (GPC) elution times were determined in toluene on commercially available standards of polystyrene (PSTY) and polymethyl methacrylate (PMMA) having M_n in the range of 10³ to 10⁵ and 10⁴ to 10⁶, respectively. In addition, elution times were determined on the discrete GPC peaks of dimer, trimer, tetramer, etc. as seen in lower molecular weight PSTY and PMMA. Intrinsic viscosities of oligomers were estimated by extrapolation of the Mark-Houwind-Sakurada equations determined from our data, and the results were used to establish a universal calibration curve over a wide range of molecular weights. A similar approach was taken by using literature data for the intrinsic viscosities of PSTY and PMMA in tetra-hydrofuran. It was verified by proton NMR that the universal calibration curve so constructed is useful at M_n, values as low as 300. No correction was necessary for chain length dependence of the detector response.     

Determination of the Molecular Weight Distribution of Polyethylene Terephthalate by Gel Permeation Chromatography

Abstract

The determination of the molecular weight distribution of polyethylene terephthalate by GPC at room temperature is described. The solvent used is o-chlorophenol-chloroform (1:9) and pure chloroform is used as eluent. K and alpha of the Mark-Houwink equation of polyethylene terephthalate and of polystyrene in this solvent system were obtained. It was shown that the universal calibration can be applied.     

水溶性凝胶渗透色谱法测定碱木素分子量

应用水溶性凝胶渗透色谱法测定了碱木素的分子量,与脂溶性凝胶渗透色谱法的测定结果基本一致。色谱柱为Ｕｌｔｒａｈｙｄｒｏｇｅｌ凝胶色谱柱,流动相为氢氧化钠溶液（ｐＨ１２）。系统考察了不同流动相对碱木素在凝胶柱上吸附的影响,结果发现,增大流动相离子强度有利于减少碱木素的吸附,但流动相的酸度对于碱木素吸附具有更重要的影响,ｐＨ值高时,碱木素吸附减弱。实验同时表明,高分子量的碱木素更易在凝胶柱上发生吸附。     

Molecular Complexes of Fullerenes C60 and C70 with Saturated Amines

New molecular complexes of fullerenes C₆₀ and C₇₀ with leuco crystal violet (LCV, 1-3); leucomalachite green (LMG, 4-6); crystal violet lactone (CVL, 7); N,N,N′,N′-tetrabenzyl-p-phenylenediamine (TBPDA, 8, and 9); N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPDA, 10, and 11); triphenylamine (TPA, 12, and 13); and substituted phenotellurazines (EPTA and TMPTA, 14, and 15) have been synthesized. Crystal structures have been solved for C₆₀ complexes with LMG (5, 6) TBPDA (8), TMPDA (10), and TPA (12). The C₆₀ molecules form closely packed double layers in 5 and 6, hexagonal layers in 10 and quasi-three-dimensional layers in 8 and 12. The substitution of disordered solvent molecules in the complexes with LMG (4, 5) by naphthalene ones results in the ordering of the C₆₀ molecules. According to IR-, UV-visible-NIR and ESR-spectroscopy the complexes have a neutral ground state. The spectra of 1-8, and 10 show intense charge transfer bands in the visible and NIR-range. On photoexcitation by white light (light-induced ESR (LESR) spectroscopy), 1 and 10 were shown to have an excited ionic state. The LESR signals were generated at light energies <2.25 eV indicating that the excited states in the complexes are realized mainly by direct charge transfer from donor to the C₆₀ molecule.     

Vibrational spectra and internal rotation barriers of cyclopentadienyl germanium trihalides: (C5H5)GeCl3, (C5H5)GeBr3 and (C5H5)GeI3

IR and Raman spectra of gaseous and solid CpGeX₃ species (Cp  C₅H₅ and X = Cl, Br, I) are reported. The results are compared with those obtained previously for CpTiCl₃. Internal rotation barriers and thermodynamic functions are reported.     

高效液相色谱法和凝胶色谱法对钨酚醛树脂的表征

应用高效液相色谱法（ＨＰＬＣ）和凝胶色谱法（ＧＰＣ）对不同合成阶段的钨酚醛树脂进行表征,以合成体系的极性和分子量的变化为依据,提出合成反应的重要控制阶段以及含钨化合物在合成反应中的行为。