线性参数logI对反相液相色谱中的非极性小分子溶质体系的表征

从理论上阐明了计量置换平衡常数的对数ｌｏｇＫａ对液相色谱中计量置换保留模型的线性参数ｌｏｇＩ起着主导作用。ｌｏｇＩ表示溶质对固定相的亲合势，且具有热力学平衡常数的性质。     

异丙基膦酸单(1-已基-4-乙基)辛酯的某些基本常数的测定

用两相滴定法测定异丙基膦酸单（１－己基－４－乙基）辛酯（ＰＴ－２，ＨＬ）在水中的溶解度Ｓ，在水中的解离常数Ｋ在水－正庚烷中的分配常数Ｋｄ及二聚常数Ｋ２，利用ＳＯＬＷＲ计算程序，简单快速地处理两相滴定数据，得到结果为：Ｓ＝３．６８ × １０－５ｍｏｌ／Ｌ，ｐＫａ＝５．４９，ｌｏｇ Ｋ２＝４． ６７，ＩｏｇＫｄ＝ ２． ６７（２５±０． ５℃）．     

1,10－双(1''－苯基－3''－甲基－5''－氧代吡唑－4''－基)癸二酮－[1,10]与1,10－菲罗啉或2,2''－联吡啶对钴(Ⅱ)的协同萃取行为研究

本文研究了１，１０－双（１＇－苯基－３＇－甲基－５＇－氧代吡唑－４＇－基）癸二酮－［１，１０］（Ｈ２Ａ）与１，１０－菲罗啉（ｐｈｅｎ）或２，２＇－联吡啶（ｄｉｐｙ）对Ｃｏ（Ⅱ）的协同萃取行为。确定了协萃配合物的组成为ＣｏＡ．Ｂ（Ｂ分别为ｐｈｅｎ和ｄｉｐｙ），求得萃取平衡常数ｌｏｇＫｅｘ分别是４．７８（Ｈ２Ａ＋ｐｈｅｎ）和１．６１（Ｈ２Ａ＋ｄｉｐｙ），并对协萃配合物的ＩＲ谱进行了讨论。     

1，10－双（1＇－苯基－3＇－甲基－5＇－氧代吡唑－4＇－基）癸二酮－［1，10］与1，10－菲罗啉或2，2＇－联吡啶对钴（Ⅱ）的协同萃取行为研究

本文研究了１，１０－双（１＇－苯基－３＇－甲基－５＇－氧代吡唑－４＇－基）癸二酮－［１，１０］（Ｈ２Ａ）与１，１０－菲罗啉（ｐｈｅｎ）或２，２＇－联吡啶（ｄｉｐｙ）对Ｃｏ（Ⅱ）的协同萃取行为．确定了协萃配合物的组成为ＣｏＡ·Ｂ（Ｂ分别为Ｐｈｅｎ和ｄｉｐｙ），求得萃取平衡常数ｌｏｇＫｅｘ分别是４．７８（Ｈ２Ａ＋ｐｈｅｎ）和１．６１（Ｈ２Ａ＋ｄｉｐｙ），并对协萃配合物的ＩＲ谱进行了讨论．     

配合物稳定性和配体酸碱强度之间的直线自由能关系──铜（Ⅱ）、锌（Ⅱ）－芬布芬－α－氨基酸三元配合物体系

在２５±０．１℃，Ｉ＝０．１ｍｏｌ·ｄｍ－３ＫＮＯ３条件下，８０％（ｖ／ｖ）ＤＭＳＯ—Ｈ２Ｏ混合溶剂中，应用ｐＨ法测定了甘氨酸，Ｌ一缬氨酸，Ｌ－异亮氨酸，Ｌ－脯氨酸，Ｌ－丝氨酸，ＤＬ－苯丙氨酸等六种α－氨基酸（缩写为α－ＡＡ，记为Ｂ配体）的酸离解常数，铜（Ⅱ）－α－氨基酸．锌（Ⅱ）－α－氨基酸二元配合物的稳定常数及铜（Ⅱ）－芬布芬－α－氨基酸（芬布芬缩写为Ｆｅｎ，记为Ａ配体）和锌（Ⅱ）－芬布芬－α－氨基酸三元配合物的稳定常数．实验发现，在下面三对参数之间，即ｌｏｇβ１０２与ｐＫ，ｌＯｇβ１１１；与ｐＫ及１０ｇβ１１１与ｌｏｇβ１０２，均存在良好的直线自由能关系．用△ｌｏｇＫＭ和△ｌｏｇβ１１１两个参量描述了三元配合物相对于母体二元配合物的稳定性．讨论了溶剂的性质，配合物分子内配体之间的疏水作用，芳环之间的堆积作用对配合物稳定性的影响．     

1, 2－亚丙基双(草酰胺根)桥联的线性三核铜(Ⅱ)配合物的合成与磁性

本文合成和表征了四种新的三核铜（Ⅱ）配合物）Ｃｕ（Ｌ）２，Ｃｕ（ＣＨ３－ｅｂｏ）（ｃｌＯ４）２（ＣＨ３ｅｂｏ表示１，２－亚丙基双（草酰胺根），Ｌ表示１，１０－菲咯啉（ｐｈｅｎ）（１），５－ｄｉｅｇａｄ －１，１０－ａｄｊｄｋｔｋ ｋｓｓｙ（ＮＯ２－ｐｈｅｎ）（２），２，２＇－联吡（ｂｐｙ（３）和４，４－二甲基－２，２－联吡啶（ｍｅ２ｂｐｙ）（４）．测定了四种配合物的变温磁化率＊７７－３００Ｋ），求     

FT合成沉淀Fe／Cu／K催化剂有效因子的计算Ⅰ．工业颗粒催化剂有效因子的计算

用包括水抑制作用的动力学方程，根据建立的反应扩散模型和ＦＴ合成化学计量关系，计算了工业原颗粒ＦＴ合成沉淀Ｆｅ／Ｃｕ／Ｋ催化剂在工业操作条件下的有效因子。根据不同的产物组成，建立了三种化学计量关系式，比较了气相反应和气液反应的有效因子，确立了ＦＴ合成沉淀Ｆｅ／Ｃｕ／Ｋ催化剂有效因子的计算方法。在ＦＴ合成反应条件下，产物蜡充满了催化剂的微孔，各组分在蜡中的扩散系数要比纯气相中的扩散系数小得多。在工况操作条件下（５２３Ｋ，２．５ＭＰａ，５００ｈ￣（－１），尾气循环比３．０），工业原颗粒（ｄ＿ｐ＝２．５ｍｍ，ｌ＿ｐ＝５～１０ｍｍ）催化剂的实际有效因子是纯气相反应的一半左右，计算的平均有效因子分别为０．４０和０．４２。     

1，2－亚丙基双（草酰胺根）桥联的线性三核铜（Ⅱ）配合物的合成与磁性

本文合成和表征了四种新的三核铜（Ⅱ）配合物｛［Ｃｕ（Ｌ）］２［Ｃｕ（ＣＨ３－ｅｂｏ）］｝（ＣｌＯ４）２（ＣＨ３ｅｂｏ表示１，２－亚丙基双（草酰胺根），Ｌ表示１，１０－菲咯啉（ｐｈｅｎ）（１），５－硝基－１，１０－菲咯琳（ＮＯ２－ｐｈｅｍ）（２），２，２’－联吡啶（ｂｐｙ）（３）和４，４’－二甲基－２，２’－联吡啶（Ｍｅ２ｐｙ）（４））．测定了四种配合物的变温磁化率（７７－３００Ｋ），求得交换参数分别为Ｊ１＝－２１９．６ｃｍ－１，Ｊ２＝－１９１．７ｃｍ－１，Ｊ３＝－２００．８ｃｍ－１，Ｊ４＝－１８５．５ｃｍ－１，表明Ｃｕ（Ⅱ）－Ｃｕ（Ⅱ）离子间存在着强的反铁磁交换相互作用．     

钴（Ⅱ）－5－取代邻菲罗啉－α－氨基酸三元配合物的稳定性研究

本文在２５．０±０．１℃，Ｉ＝０．１ｍｏｌ·ｄｍ（－３）ＫＮＯ３存在下，采用ｐＨ法测得了５－取代邻菲罗啉的质子化常数以及钴（Ⅱ）与５－取代邻菲罗啉、α－氨基酸的二元、三元配合物的稳定常数．结果表明三元配合物的稳定性与５－取代邻菲罗啉的质子化常数、取代基常数均存在直线自由能关系．并用三元配合物稳定性的表征值ｌｏｇＫＭ、△ｌｏｇＫ，讨论了三元配合物的稳定性，发现钴（Ⅱ）与配体５－取代邻菲罗啉之间也存在着ｄ－ｐ反馈π键．该π健的强度对三元配合物稳定性有着显著影响．     

气相色谱法研究有机物在河流沉积物上的吸附

本文提出用有机物在沉积物上的色谱比保留体积值估算沉积物有机碳吸附系数，为此，以河流沉积物作气相色谱固定相，用测定气相色谱固定液相对极性和有机物比保留体积的方法，测定了沉积物相对极性和有机物在其上比保留体积，研究了Ｖｇ与Ｋｏｃ的相关性，结果表明，萘的线性关系式为ｌｏｇＫ＝０．１８＋３．１１（ｒ＝０．９８３１，ｎ＝５）。硝基苯的关系为ｌｏｇＫ＝０．２４ｌｏｇＶｇ＋２．５９（ｒ＝０．９５４４，ｎ＝５）．     

有机酸在阴离子交换树脂上的保留行为及其机理

研究了有机酸在阴离子交换树脂上的保留行为。首次报道了有机酸在阴离子交换色谱过程中的“多峰现象”,即一种有机酸有两个或两个以上的色谱峰流出色谱柱。对这种“多峰现象”形成的机理进行了初步探讨,提出了有机酸离解后的不同价数阴离子在阴离子交换树脂上同时保留的机理。研究中还发现离解很弱的有机酸的保留行为不完全符合离子交换机理。     

土壤淋溶柱色谱中同系物、氯代苯保留值与流动相组成、沸点的交点规律

基于土壤淋溶柱色谱符合logk'-ψ的线性保留方程,在同系物（正构烷基苯、甲基苯）和氯代苯中,同类溶质与固定相（土壤）和淋洗剂（甲醇-水）有相似的作用方式,所以溶质保留值（logk'）与淋洗剂有机调节剂浓度间存在浓度交点,与沸点间存在沸点交点规律,并用实验进行了验证。     

Retention characteristics of an immobilized artificial membrane column in reversed-phase liquid chromatography

Retention for a varied group of compounds on an immobilized artificial membrane column (IAM PC DD2) with a methanol-water mobile phase is shown to fit a second-order model for the retention factor (log k) as a function of the volume fraction of organic solvent. The numerical value of the intercept obtained by linear extrapolation to zero organic solvent (log k(w)) is shown to depend on the range of mobile phase composition used for the extrapolation. Each series of intercepts so obtained represents a different hypothetical distribution system as identified by the system constants of the solvation parameter model. Although a linear model is a poor fit for isocratic retention data, the linear solvent strength gradient model provides a reasonable estimate of isocratic retention factor values that are (slightly) larger than experimental values, but provide the same chemical information for the system. These preliminary results suggest that gradient elution may prove to be a rapid and useful method for creating system maps for column characterization and method development. In this work a system map is provided for methanol-water compositions from 0 to 60% (v/v) methanol and additional system constants for acetonitrile-water compositions containing 20 and 30% (v/v) acetonitrile. It is shown that the main factors contributing to retention on the IAM PC DD2 column are favorable cavity formation and dispersion interactions, electron lone pair interactions and the hydrogen-bond basicity of the sorbent. The latter feature more than any other distinguishes the IAM column from conventional chemically bonded phases. Interactions of a dipole-type (weakly) and inability to compete with the mobile phase as a hydrogen-bond acid reduce retention. A comparison of system constant ratios is used to demonstrate that the retention properties of the IAM column are not easily duplicated by conventional chemically bonded phases. The retention characteristics of the IAM column, however, are strongly correlated with the retention properties of pseudostationary phases used for micellar electrokinetic chromatography, which provide a suitable alternative to IAM columns for physical property estimations. By the same comparative method it is shown that retention on the IAM column possesses some similarity to biomembrane absorption processes, allowing suitable correlation models to be developed for the estimation of certain biopartitioning properties.     

Quantitative structure-retention relationship for photosystem Ⅱ inhibitors in RP-HPLC

Using factor analysis (principle component) and multiple linear regression methods,4 solute-related structure parameters were selected from 10 structure parameters and the relationships between the retention properties (logk') of 25 2-cyano-3-methylthio-3-substituted amino-acrylates and the 4 parameters were established.There is a good agreement between the observed k' values and the predicted fe' values.     

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.     

Hydrophilic interaction chromatography separation mechanisms of tetracyclines on amino-bonded silica column

Effects of mobile-phase variations on the chromatographic separation on amino-bonded silica column in hydrophilic interaction chromatography (HILIC) were investigated for four zwitterionic tetracyclines (TCs): oxytetracycline, doxycycline, chlortetracycline, and tetracycline. A mixed-mode retention mechanism composed of partitioning, adsorption, and ion exchange interactions was proposed for the amino HILIC retention process. Buffer type and pH significantly influenced the retention of TCs, but showed similar separation selectivity for the tested analytes. Experiments varying buffer salt concentration and pH demonstrated the presence of ion exchange interactions in TCs retention. The type and concentration of organic modifier also affected the retention and selectivity of the analytes, providing direct evidence supporting the Alpert retention model for HILIC. The retention time of the analytes increased in the following order of organic modifiers: tetrahydrofuran < methanol < isopropanol < acetonitrile. The linear relationships of logk' versus %water (v/v) curve and logk' versus logarithm of %water (v/v) in the mobile phase indicated that TCs separation on the amino phase was controlled by partitioning and adsorption. The developed method was successfully utilized in the detection of TCs in both river water and wastewater samples using solid-phase extraction (SPE) for sample cleanup.     

Prediction of Surfactant Retention in Porous Media: A Robust Modeling Approach

Demands for hydrocarbon production have been increasing in recent decades. As a tertiary production processes, chemical flooding is one of the effective technologies to increase oil recovery of hydrocarbon reservoirs. Retention of surfactants is one of the key parameters affecting the performance and economy of a chemical flooding process. The main parameters contribute to surfactant retention are mineralogy of rock, surfactant structure, pH, salinity, acidity of the oil, microemulsion viscosity, co-solvent concentration, and mobility. Despite various theoretical studies carried out so far, a comprehensive and reliable predictive model for surfactant retention is still found lacking. In this communication, a mathematical method based on machine learning approach, namely, least square support vector machine modeling is evolved for this purpose. To this end, the model was developed and tested using experimental dynamic surfactant retention data over a wide range of conditions. The results show that the developed model provides predictions in good agreement with experimental retention data. Moreover, it is shown that the developed model is capable of simulating the actual physical trend of surfactant retention versus three most important input parameters: total acid number of oil, pH, and mobility ratio. Finally, for detection of the probable doubtful retention data, outlier diagnosis was performed on the whole data set.     

Influence of the Regression Technique on the Extrapolated Retention Values of Single-Point Adsorption Compounds on Silica Gel

JPC – Journal of Planar Chromatography – Modern TLC - The retention (RM) values of nine one-point adsorption model compounds: diphenylamine, indol, 2-naphtol, 1-naphtol, 1-naphtylamine,...     

Retention model for the separation of anionic metal-EDTA complexes in ion chromatography

A retention model is derived for complex anions eluted from an anion-exchange column with multiple ionic eluents containing hydrogencarbonate, carbonate, and hydroxyl species and the sample solution, containing transition metals, anions and complexing ligand. The theory is based on the generalized ion-exchange equilibrium, protonation and complex-formation equilibria. The unknown parameters of chromatographic ion-exchange equilibrium constants for sample and eluent species are determined from the experimental retention data by iterative minimization, using a non-linear regression algorithm. The model was utilized to predict the retention behaviour of CdEDTA²⁻, CoEDTA²⁻, MnEDTA²⁻ and NiEDTA²⁻ ions. The capacity factors of complex ions were determined for wide ranges of pH values and eluent concentrations. Good agreement was obtained between the observed and predicted retentions.