土壤淋溶柱色谱中有机调节剂对保留的影响

 摘要：系统考察了55种非离子型化合物（包括11个氯代苯类、14个烷基苯类、22个多苯和多环芳烃类化合物、8个农药）在土壤淋溶柱色谱和较宽的淋洗剂（甲醇-水）组成范围内容量因子（k'）与甲醇体积分数（ψ）的关系。用自制加压装柱机将标准土壤干法装填成10mmi.d.×100mm的液相色谱柱,ψ=00.80的等度淋洗剂的流速1mL·min-1,柱温(25.0±0.1)℃,用UV检测器在线检测。实验表明,logk'=logkw+aψ+bψ2和logk'=logkw-Sψ两式均可以用来描述保留规律,但后者因其计算简     

某些非极性和极性溶质在苯和甲醇及二者混合物中的偏摩尔体积V0, 298.15 K

密度法测定了298.15 K下乙醇、环己烷、三氯甲烷、甲苯、丙酮、四氯化碳、乙腈、二甲基甲酰胺、二甲基亚砜在甲醇或苯及两者混合物中的无限稀释偏摩尔体积. 密度测定所用溶液中溶质的浓度范围是0.2一1.5 m; 甲醇和苯混合物是全组成比范围. 溶质偏摩尔体积随甲醇-苯组成比的变化趋势反映了几种分子间相互作用结果即三种分子间物理型分子间相互作用; 溶质与甲醇分子氢键缔合相互作用; 溶质同甲醇或苯的弱络合作用。     

某些非极性和极性溶质在苯和甲醇及二者混合物中的偏摩尔体积V~0,298.15K

密度法测定了298.15K下乙醇、环己烷、三氯甲烷、甲苯、丙酮、四氯化碳、乙腈、二甲基甲酰胺、二甲基亚砜在甲醇或苯及两者混合物中的无限稀释偏摩尔体积.密度测定所用溶液中溶质的浓度范围是0.2一1.5m;甲醇和苯混合物是全组成比范围.溶质偏摩尔体积随甲醇-苯组成比的变化趋势反映了几种分子间相互作用结果即三种分子间物理型分子间相互作用;溶质与甲醇分子氢键缔合相互作用;溶质同甲醇或苯的弱络合作用。     

离子交换与离子排斥色谱柱串联体系中阳离子的多峰现象及其机理

研究了串联柱体系中阳离子的“多峰现象”。在阳离子交换柱后面接上阴离子分析用的离子排斥柱构成一个串联柱体系,当以酒石酸（ＴＡ）和吡啶二羧酸（ＰＤＣ）的混合溶液作淋洗液时,每一种阳离子同时出现３个色谱峰。这是因为从阳离子交换柱流出的阳离子与有络合作用的两种淋洗剂阴离子形成络合物,使流动相中淋洗剂阴离子浓度减少以及两种淋洗剂阴离子在离子排斥柱中被保留且保留值不同。     

固定化冠醚树脂的特性及离子色谱应用研究 Ⅱ.间接光度检测中苦味酸淋洗剂的一些性质

本文报道用固定化冠醚作色谱填料的无抑制柱间接光度离子色谱法中高灵敏度淋洗剂的性能。苦味酸具有稳定的生色基团和较高的摩尔吸光系数,光学性质良好,是间接光度离子色谱法中优良的淋洗剂。苦味酸浓度以4×10~(-6)mol/L 为最佳。在苦味酸中引入少量甲醇、乙醇、丙酮或氯仿,对提高淋洗剂的灵敏度有利。在苦味酸浓度相同的条件下比较几种填料,其色谱峰高按如下次序递增,固定化二苯并-18-冠-6<固定化二苯并-30-冠-10<固定化苯并-15-冠-5。     

氨基苯磺酸和氨基萘磺酸在反相色谱中的保留行为

本文考察了冲洗剂中强组分浓度、无机盐浓度和酸度对保留值的影响,结果表明在溶质的 lnk 与 C_b 间线性关系中不能包括 C_b=0时的实验点。同时还观察到线性回归的 a 值与C_b=0时实测的 lnk′值存在较好的线性关系,酸度对 k′值的影响较复杂;溶质的保留值随无机盐浓度的增加而增大。     

皂角苷对镧、铈、钇的淋洗效果及影响因素研究

以稀土污染土壤为研究目标,采用生物表面活性剂皂角苷淋洗土壤中La,Ce和Y,探讨皂角苷浓度、淋洗液pH值、土液比和淋洗时间对淋洗效果的影响。结果表明,皂角苷浓度为25 g·L~(-1),pH=5.5,土液比为1∶40,淋洗时间为6 h时,土壤中La,Ce和Y的淋洗率分别为58.05%,57.78%,64.43%。对比淋洗前后土壤中稀土的形态分布,弱酸可提取态与可还原态的淋洗效果最为明显;弱酸可提取态含量均降低了80%以上,La,Ce和Y的可还原态含量分别下降58.98%,57.76%,69.32%,可氧化态分别下降35.71%,47.57%,98.28%,Ce的残渣态降低了64.64%,而La和Y的残渣态分别上升了32.37%,322.23%。且淋洗后土壤中La,Ce和Y稳定性指数IR分别提高了50.58%,7.55%和104.26%,降低了土壤中稀土的生物可利用性。     

作物秸秆降解中稀有机酸的萃取回收

作物秸秆有机降解的研究中,有机酸的回收利用是一个非常重要的环节,本研究采用低沸点的乙酸乙酯和高沸点的磷酸三丁酯（TBP）作萃取剂,对作物秸秆有机酸（乙酸,丙酸）降解中不同浓度的稀有机酸溶液（汽提液和洗涤液）用液－液淬取法回收,结果表明：磷酸三丁酯的萃取能力大于乙酸乙酯,同一萃取剂对丙酸的萃取效果比对乙酸好。     

鼠李糖脂对镧的淋洗效果及影响因素研究

以La为目标污染物,通过鼠李糖脂淋洗土壤试验,考察鼠李糖脂对La的淋洗效果及溶液pH影响,以淋洗前后不同形态稀土元素含量变化为基础,分析淋洗剂对La的稳定性和流动性的影响。结果表明:鼠李糖脂对土壤中稀土元素吸附能力较弱,最佳淋洗pH为6.9,最大淋洗效率为10.24%,相同条件下Cu,Zn的最大淋洗效率分别为67.75%和18.33%。淋洗剂pH值对淋洗效果的影响较大,考察的3个pH值中淋洗剂pH为6.9时淋洗效果最佳。多次淋洗有助于提高La的淋洗效率,最大累积效率为17.76%。当淋洗剂pH=10时,多次淋洗累积效率为7.42%,由于淋洗剂为碱性,使得体系中氧化结合态稀土元素的含量不断升高,该条件下稀土元素稳定性指数MF相对其他条件最大提高了33.67%,有助于稀土元素在土壤中的固化。     

异构丁醇在四氯化碳、正庚烷、苯和1,2二氯乙烷中的红外光谱研究

利用FT-IR,测定了四种异构丁醇十四氯化碳、+正庚烷, +苯和1,2-二氯乙烷稀溶液在3800—3000 cm~(-1)内的红外吸收光谱。缔合峰与自由羟基峰的面积之比与溶质、溶剂的性质有关, 且在极稀溶液区与溶质的质量百分比浓度之间有良好的直线关系。本文又运用1-n(环状)模型对有关体系进行了对比研究。结果表明, 丁醇分子支链度的增加以及丁醇分子与苯和1,2-二氯乙烷之间的特殊相互作用, 降低了醇分子的缔合能力。稀溶液中, 丁醇分子在苯和1,2-二氯乙烷中主要以单体和环状二聚体形式存在, 在四氯化碳中以单体和环状三聚体形式存在, 而正丁醇分子在正庚烷中主要为单体和环状四聚体, 异、仲、特丁醇主要为环状三聚体和单体。     

反相液相色谱中同系物保留值与流动相组成的交点规律

本文在作者提出的反相液相色谱中同系物保留值与常沸点的交点规律基础上，推导出系物保留值与流动相组成的交点规律，用大量实验数据作了检验。并用新交点方程式，由化合物在一个流动相组成下的保留值，预测该化合物在任一流动相组成下的保留值，对１４组同系物在５种色谱柱上５类流动相下的验算结果表明，７２１个数据点的绝对平均误差为２．８％。     

Solvent composition effects in column and thin layer chromatography of aromatic nitro compounds on alumina

Summary The relationship between R _M and the concentration of the polar solvent in the moving phase was investigated for a number of aromatic nitro compounds with additional polar groups (amino, methoxy, carbomethoxy, aldehyde). TLC data were correlated with analogous column chromatography results. Linear R _M (logk') vs. logX _S relationships obtained for both techniques are interpreted in terms of a molecular model of adsorption.     

Hydrophobicity parameters determined by reversed-phase liquid chromatography. Xiv. Application of a new hydrogen-accepting scale of monosubstituted pyrazines to analysis of the relationship between octanol-water partition coefficients and retention factors measured in different mobile phases

We recently proposed a new H-accepting scale, SHA, for monosubstituted pyrazines, and demonstrated that this parameter works effectively in expressing the relationship between logP (P: 1-octanol/water partition coefficient) and logk' (k': retention factor derived from reversed phase liquid chromatography) with aqueous methanol solutions as the mobile phase, according to the equation: logk' = alogP+rhosigmaI+sSHA+const., where sigmaI represents the electronic substituent constant. In this work, we have extended the same treatment to analysis of logk' measured in mobile phases containing different organic modifiers such as 1-propanol, acetonitrile, and dioxane, and found that the above equation is still useful. By comparing the correlations obtained, it was confirmed that the parameter SHA could be universally utilized for representing the difference in H-bonding effects involved in different partitioning systems.     

关于凝固点和凝固点降低

对水的凝固点、三相点、标准凝固点和正常凝固点概念及其图示进行了辨析。     

Cloud Point Extraction of Serum Albumin and Its Spectrophotometric Determination in Serum Samples

Abstract

A new method based on the cloud point extraction (CPE) separation and ultraviolet spectrometry determination was proposed for the determination of albumin. When the system temperature is higher than the cloud point extraction temperature (CPT) of the mixed surfactant of p‐octyl polyethyleneglycolphenyether (Triton X‐100) and sodium dodecyl sulfate (SDS), serum albumin could be extracted into surfactant‐rich phase. The main factors affecting the cloud point extraction were investigated systematically. Under the optimized conditions, the determination limit for serum albumin as low as 0.18 µg/mL was obtained by preconcentrating a 10 mL sample solution, and the relative standard deviation (n=10, c=40.0 µg/mL) was 3.77%. The proposed method was applied to the determination of albumin in serum samples. The results obtained by this method were in good agreement with coomassie brilliant blue (CBB).     

Intersection Point Rule for the Retention and Mobile Phase Composition of the Homologues in Reversed-Phase Capillary Electrochromatography

Capillary Electrochromatography is a kind of micro-separation techniques newly developed in resent years. It is of both high selectivity of HPLC and high efficiency of capillary electrophoresis. This subject is being studied widely now. However, still many imperative problems need to be explored in the respect of retention rule. In this paper,based on the retention rule in RP-HPLC, the intersection point rule for the retention of homologues and the volume fraction of the organic modifier in the mobile phase in the reversed-phase capillary electrochromatography (RP-CEC) was derived, and was testified by a lot of experimental data.     

The Parameters of Intersection Point Equation Between Retention and Carbon Number for Homologues in Supercritical Fluid Chromatography

Supercritical fluid chromatography (SFC) techniques have been developing rapidly, now much attention has been paid to the research for its thermodynamic basis. Based on thermodynamic theory, we have derived the straight linear relationship between the logarithm of capacity factor and carbon number for homologues in SFC. There is a common intersection point among the ln k' vs. n straight lines of homologues at different temperatures. We can determine the intersection point equation of homologues in SFC.     

浊点萃取技术及其在有机化合物分离分析中的应用

浊点萃取是基于表面活性剂水溶液中相分离现象的萃取浓缩技术,已成功实现了与HPLC、CE和FI等分析仪器的联用,用于各种金属离子、生物分子和不同极性有机化合物浓缩分离处理,是一种替代有机溶剂萃取的良好形式。本文简要介绍了浊点萃取技术的原理和流程,详细总结了在有机化合物分离分析中的应用以及与不同分析仪器联用时遇到的问题和处理方法。     

非离子表面活性剂浊点萃取甘草酸体系的特性

用非离子表面活性剂Triton X-100和NaCl盐溶液在一定温度下形成的浊点体系为萃取介质,重点研究了浊点萃取甘草酸过程中凝聚相及水相的谱学性质和微观结构。 结果表明,随着温度的升高,红外谱图中O-H的振动吸收峰和C-O骨架伸缩振动峰会向高波数移动,而在浊点温度时,波数变化明显。 浊点体系的主体相具有粒度性质特征,吸附溶质后的凝聚相胶团粒径增大。 随着甘草酸浓度的升高,胶团从7.7 nm增大至20 nm以上,有类似聚集的现象。     

闭杯闪点法测定氢化三丁基锡的闪点

使用MINIFLASH FLA全自动中温八杯闪点仪(闭杯闪点法)测定了氢化三丁基锡的闪点。探讨了诸多因素如样品的储存状态、点火次数、升温速率、大气压的校正、仪器保养方法等对闪点测定的影响。