气相色谱保留指数通用数据库的研究（一）PEG20M石英毛细管柱保留指数可比性的考察

 测定了６１个不同类型化合物在６根ＰＥＧ２０Ｍ石英毛细管柱上的保留指数（ＲＩ），结果表明各柱间ＲＩ存在相当大的差异，给ＲＩ数据库的应用带来了困难，结合文献数据，从固定液本身、相界面吸附、热力学函数及柱极性的表征等方面探讨其原因，认为以烷烃为主的相界面吸附是影响ＲＩ可比性的重要因素，同时柱制备过程带来的影响也不容忽视。     

气相色谱保留指数通用数据库的研究（三）不同柱温模式下保留指数的相互转换

 由于升温模式（Ｔ_０，ｒ）、色谱柱和操作参数（Ａ，Ｔ_ｂ，β）的差别，使得Ｔ_Ｒ不同而影响Ｉ_（ＴＰ）的可比性，其影响的大小随恒温保留指数ＲＩ的温度系数的增加而增加。同时，由于Ｔ_Ｒ与ｎ偏离了线性关系，采用保留温度线性插值方法计算Ｉ_（ＴＰ），方法本身就在一定程度上会使Ｉ_（ＴＰ）的可比性差，即使恒温ＲＩ的温度系数为零，Ｉ_（ＴＰ）也会随ＧＣ条件而改变。根据恒温与线性程升的保留值方程建立的各种柱温模式下的保留指数相互转换方法能准确快速地预测不同柱温模式下的保留指数，以此来建立通用数据库以适应不同的分析条件的需要。     

气相色谱保留指数通用数据库的研究（三）不同柱温模式下保留指数的相互转换

由于升温模式（Ｔ_０，ｒ）、色谱柱和操作参数（Ａ，Ｔ_ｂ，β）的差别，使得Ｔ_Ｒ不同而影响Ｉ_（ＴＰ）的可比性，其影响的大小随恒温保留指数ＲＩ的温度系数的增加而增加。同时，由于Ｔ_Ｒ与ｎ偏离了线性关系，采用保留温度线性插值方法计算Ｉ_（ＴＰ），方法本身就在一定程度上会使Ｉ_（ＴＰ）的可比性差，即使恒温ＲＩ的温度系数为零，Ｉ_（ＴＰ）也会随ＧＣ条件而改变。根据恒温与线性程升的保留值方程建立的各种柱温模式下的保留指数相互转换方法能准确快速地预测不同柱温模式下的保留指数，以此来建立通用数据库以适应不同的分析条件的需要，特别是从２种升温模式出发预测其它柱温模式下的保留值能更方便地对复杂样品的分离条件进行优化。     

气相色谱保留指数通用数据库的研究（二）PEG 20M柱间保留指数的相互关系

针对极性柱间保留指数的可比性差这一特点，选择了以常用的ＰＥＧ２０Ｍ为代表，根据气－液色谱保留的一般模型，并考虑柱间选择性作用的微小差异及气－液相界面面积ＡＧＬ大小不等，建立了柱间保留的相互关系方程。对６１个不同结构类型的化合物在１００℃和７５℃柱温下６根ＰＥＧ２０Ｍ石英毛细管柱上的应用表明，结果准确，关联后计算得到的保留指数与实际测定值间的绝对平均偏差为１ｉ．ｕ．，从而为极性柱上保留指数通用数据库的建立提供了方法。     

气相色谱保留指数通用数据库的研究（二）PEG 20M柱间保留指数的相互关系

 针对极性柱间保留指数的可比性差这一特点，选择了以常用的ＰＥＧ２０Ｍ为代表，根据气－液色谱保留的一般模型，并考虑柱间选择性作用的微小差异及气－液相界面面积ＡＧＬ大小不等，建立了柱间保留的相互关系方程。对６１个不同结构类型的化合物在１００℃和７５℃柱温下６根ＰＥＧ２０Ｍ石英毛细管柱上的应用表明，结果准确，关联后计算得到的保留指数与实际测定值间的绝对平均偏差为１ｉ．ｕ．，从而为极性柱上保留指数通用数据库的建立提供了方法。     

离子交换色谱中混合保留机理的研究

鉴于离子交换色谱中被测离子和有机聚合物树脂之间存在的吸附作用, 选择阴离子交换色谱柱IonPacAS9-HC为研究对象, 针对离子交换色谱中的吸附保留行为, 从色谱混合保留机理的角度出发, 考虑各色谱柱固定相含量和界面吸附面积的不同, 建立柱间保留的相互关系方程. 在五根不同批号IonPacAS9-HC (250 mm×2 mm I.D.)柱上, 以含50%乙腈(V/V)的9 mmol/L Na₂CO₃为流动相, 0.25 mL/min流速, 对12个不同结构类型的无机和有机阴离子(氟离子、氯离子、硫酸根、磷酸根、二羟基丁酸、丙酮酸、乙酸、丙烯酸、苯甲酸、丙二酸、酒石酸和邻苯二甲酸)的保留行为进行研究, 并采用推导所得的混合保留机理模型对溶质这一保留特征进行表征, 结果较为理想, 其中一价离子的相关系数为0.9～0.999, 二价离子的相关系数为0.999～1, 为离子交换色谱中吸附保留行为的研究提供了新方法.     

毛细管气液色谱保留过程的研究

以ＰＥＧ２０Ｍ为代表研究了石英毛细管柱气液色谱保留过程,提出了利用毛细管柱测定分配和吸附常数的公式,并测定了９个温度下的分配和吸附常数。计算了８０℃和１２０℃下４支不同液膜厚度柱上吸附对保留的贡献。结果表明,在薄液膜的柱子上界面吸附对保留具有重要贡献;温度升高可以降低弱极性化合物（如正构烷烃和饱和醚）吸附对保留的贡献,但对其它化合物影响不明显。验证了正构烷烃、２－酮系列和正构伯醇的吸附常数的碳数规律。     

4，4''-（-3，3''二甲基）联苯二胺（o-Tolidine）作紫外探针试剂的间接光度色谱法研究(I)—o-Tolidine在反相色谱柱上的吸附性能

]用甲醇-水缓冲溶液作流动相，测定紫外探针试剂o-Tolidine在反相（ODS）柱上的吸附等温线。Freundlich吸附等温方程能解释探针试剂在ODS上的吸附。分别得到了在不同流动相条件下o-Tolidine的吸附等温方程。流动相的组成如流动相的PH值、甲醇含量以及有机添加剂的性质和浓度均影响o-Tolidine在柱上的吸附。o-Tolidine在反相色谱柱上的吸附量与间接光度色谱中的溶质保留和检测响应有一定的关系。     

保留方程式和流动相体积

从溶质的保留方程式出发,讨论了液相色谱柱中流动相体积V_m和各种测量V_m方法. 借助乙腈在C₈键合相上的绝对吸附等温线,评价了这些测量方法的局限性.     

同步逆流色谱仪固相保留分析

为了提高同步逆流色谱仪的固相保留率,扩大逆流色谱仪的应用范围,本文通过结合物理、数学知识,分析影响逆流色谱仪固相保留率的主要因素：固-液摩擦力、液-液摩擦力之间的相互影响,并且数学模型验证了平面螺旋柱的切向离心力作用,三者共同决定了流动相的在柱内流速的改变,从而影响到柱内流动相的横截面积,继而影响到固定相的横截面积,最终决定了固相保留率的大小,并通过实验结果加以验证,得出F-H-U与R-H-U另种模式的固相保留效果最好。     

Retention indices in the analysis of food aroma volatile compounds in temperature-programmed gas chromatography: database creation and evaluation of precision and robustness

A retention index (RI) database containing 250 volatile compounds was created on a polar stationary phase column and validated for food aroma characterisation. Precision of the retention indices (RIs) was assessed by performing replicated injections of a representative number of volatiles under the same experimental conditions: differences lower than 1 U were observed for all the compounds. Robustness was evaluated by carrying out injections of the same set of volatile compounds under different experimental conditions, i.e. program temperature, column batches and instrumentation. Excellent results were obtained with a maximum difference in the RI values of 10 U. The capabilities of the created database for food aroma characterisation were finally evaluated by analysing the volatile fractions of different food matrices such as dry sausages, cheese and bread. A great number of volatile compounds were identified in the analysed samples on the basis of their RI, thus proving the usefulness of the RI collections in the field of food analysis.     

Study on the Retention Behavior of Aromatic Carboxylic and Sulfonic acid on a New Anion Exchange Column

Ion chromatography (IC) has gradually developed into a preferred method for the determination of inorganic anions. And in recent years some low molecular aliphatic acid can be also separated in the ion exchange column with the development of stationary phase. But for the determination of aromatic ionic compounds there are some problems. The aromatic anions show enhanced retention due to interaction with the π electrons of the aromatic backbone. Although the addition of an organic modifier can alleviate the difficulty, it is not the ultimate solution. IonPac AS20 column was developed using a unique polymer bonding technology and its substrate coating is aliphatic backbone. The polymer is completely free of any π electron‐containing substituents in the AS20 column. In this paper, the retention behavior of aromatic carboxylic and sulfonic acid on two hydroxide‐selective columns, IonPac AS11‐HC, AS16, and the new column AS20 was also studied. The result showed that the retentions of ten compounds on three columns were different with each other because of their different column characteristics. Among them 4‐chlorobenzene sulfonic acid, 3,5‐dihydric benzoic acid and salicylic acid obviously exhibited the weakest retention on the IonPac AS20. It was showed that π‐π bond function between anion and stationary phases was weakened in AS20 column because its polymer was completely free of any π electron‐containing substituents. So in this paper the AS20 was selected as an analytical column to separate ten aromatic ionic compounds, fumaric acid with conjugate bond included. The retention behavior, separation of the ten compounds and effect of temperature on their retention in the anion‐exchange column AS20 (2 mm) were studied. The result showed that those compounds could be separated with each other when running in gradient program and the organic modifier was unnecessary during the separation. So it is showed that AS20 column can be used as a separating column because its polymer is completely free of any π electron‐containing substituents. Finally, the effect of temperature on the retention behavior in AS20 column was studied and it was showed that the retention of nine compounds exhibited endothermic behavior.     

The correlation equations describing retention index data on OV-101, OV-275 and PEG 20M.n-alkanes andn-alkynes

Summary The correlation equations between Kovats retention indices ofn-alkenes andn-alkynes, column temperature and number of carbon atoms in molecules of these compounds on OV-101, OV-225 and PEG 20M capillary columns have been calculated. The two variable equationI=A + B · n + C / T give a good fit and are the simplest for practical use.     

HPLC Retention Index Scale for Nitrogen-Bridged Compounds

Abstract

Retention indices of some nitrogen-bridged compounds having pharmacological activity have been determined. A retention index scale based on the relative retention of a homologous series of C₃-C₂₃ 2-keto alkanes has been worked out. Linear relationships were found between RI and logP, allowing a prediction of retention indices.

The relationships between the structures and the retention indices of these compounds have been interpreted.     

Reproducibility of retention indices measurement of alkylbenzenes on crosslinked methyl silicone phase fused silica capillaries

Summary Reproducibility of the Kovats retention indices of alkylbenzenes was studied on conventional “PONA” fused-silica capillary columns coated with crosslinked dimethyl silicone phase, with a film thickness of 0.5 μm. The data were compared with those obtained on conventional OV-101 columns. The tested PONA columns showed reproducible chromatographic properties, capacity ratios and high efficiencies. Having a standard deviation of s=0.03 i.u. of the retention indices on a single column, the column-to-columns differences were found to be up to 0.3 i.u. Higher indices were determined for crosslinked columns, the difference being in most cases about one i.u.     

气相色谱保留指数定性方法研究进展

综述了程序升温气相色谱保留指数,I^T与Kovats恒温保留指数,之间的关系、I^T的标准化和重现性问题以及定量结构保留指数关系(QSRR)研究进展;对于应用特殊检测器和极性柱定性、对多环芳烃和多氯联苯类物质利用保留指数定性的情况,选择非正构烷烃类同系物作为参考标准时准确性大为提高,比较了由此得到的保留指数与Kovats保留指数的关系;展望了利用保留指数定性的前景。     

Gas chromatographic study of acetyl derivates of chlorinated guaiacols

Summary The gas chromatography of acetyl derivatives of guaiacol and all chlorinated guaiacols has been studied on SE-30, OV-351 and Carbowax 20M capillary columns. The retention order and relative retention times under isotermal and temperature-programmed conditions are discussed. Different retention times for all mono- and dichloro compounds have been observed on the SE-30 column. However, all trichloroguaiacol isomers were separated only on polar columns. The best overall temperature-programmed separations have been achieved on an SE-30 capillary column.