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Predicting Chromatographic retention time of C10-Chlorinated Paraffins in Gas Chromatography-Mass Spectrometry Using Quantitative Structure retention Relationship

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Chemical Research in Chinese Universities 2015年第2期31卷 192-197页

作者： XIA Zhenzhen CAI Wensheng SHAO Xueguang Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) State Key Laboratory of Medicinal Chemical Biology Research Center for Analytical Sciences College of Chemistry Nankai University Tianjin 300071 P. R. China

Chlorinated paraffins（CPs） are potential persistent organic pollutants（POPs）, which threat the safety of environment and organisms. However, the analysis of CPs is a difficult task due to their complex composition containing thousands of congeners. In the present work, quantitative structure retention relationship（QSRR） of CPs was studied. A total of 470 molecular descriptors were generated, for describing the structures of 28 CPs and 12 descriptors relevant to retention time of the CPs were selected by stepwise regression. Then, QSRR models between retention time on the one hand and the selected descriptors on the other hand were established by multiple linear regres- sion（MLR）, partial least squares（PLS） and least square support vector regression（LS-SVR）. The result shows that PLS model is better than MLR and LS-SVR, obtaining a squared correlation coefficient（r2） of 0.9996 and a root mean squared error（RMSE） of 0.015. The PLS model was then used to predict the retention time of 49 C10-CPs. Three of them were investigated by gas chromatography coupled with mass spectrometry（GC-MS）. A well-defined correlation was found between the measured retention time and the predicted value.

关键词： Chlorinated paraffin Multivariate calibration retention time Quantitative structure retention relationship

Prediction of retention time of Solutes under Linear Gradient Elution Conditions in RP-HPLC

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Chinese Journal of Chemistry 2003年第8期21卷 1084-1087页

作者：杨更亮田宝娟Department of Chemistry Normal College of Baoding Baoding 陈义王德先 College of Chemistry and Environmental Science Hebei University Molecular Science Center Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Molecular Science Center Institute of ChemistryChinese Academy of Sciences

A model for predicting retention time of solutes under linear gradient elution conditions has been established. In this model, the theoretical expressions under different elution modes were derived and tested with the retention behaviors of p hydroxybenzaldehyde, vanillin, biphenyl, phenanthrene in gradient elution. With taking into account the dwell time of the instrumental system, the theoretically predicted retention times agree well with those experimentally determined.

关键词： high performance liquid chromatography gradient elution retention time prediction

A Study of retention time Gradient Effect of Gradientally Loaded Columns

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Chemical Research in Chinese Universities 1990年第4期6卷 276-280页

作者： Yun Xiqin, Kou Dengmin, Li Yanhong and Lu Xianyu (Department of Chemistry, Nankai University, Tianjin)

In this work, the 'retention time gradient effect' of gradient GC columns is intensively studied to establish some equations and formulas for structure calculation of chromatographic columns. In addition, the relevant... 详细信息

关键词： GC column Gradientally loaded GC column retention time Gradient effect

Simultaneous Prediction of retention times and Peak Shapes of Sulfonamides in Reversed-Phase High-Performance Liquid Chromatography

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Transactions of Tianjin University 2018年第3期24卷 256-262页

作者： Xiaobing Wei Zhengji Pang Guoliang Fan Xinhua Xu Lihong Wang School of Materials Science and Engineering Tianjin University Department of Applied Chemical Engineering Ningbo Polytechnic School of Agricultural and Food Engineering Shandong University of Technology

In this paper, we propose a novelmethod based on the plate theory to simultaneously predict retention times and peak shapes under gradient elutions and different flow rates by reversed-phase high-performance liquid chromatography. The proposed method yielded excellent retention prediction results in experiments with 16 common sulfonamides under 18 gradient conditions and four different flow rates, including 0.7, 1.0, 1.3, and 1.5 mL/min. The mean absolute deviation was 0.70%, which indicates accurate prediction. Moreover, the proposed method predicts the change wellin peak shapes caused by the expansion or compression ofpeaks under different gradient conditions.

关键词： retention time Peak shape Prediction RP-HPLC Sulfonamide

Reducing DRAM refreshing in an error correction manner

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Science China(Information Sciences) 2015年第12期58卷 190-203页

作者： ZHU DanFeng WANG Rui WEI YanJiang QIAN DePei School of Computer Science and Engineering Beihang University

Dynamic random access memory(DRAM) is facing the challenge of technology scaling. The decreasing feature size makes it harder to make DRAM cells which can keep the current data-holding time. When DRAM cells cannot hold data for a long time, DRAM chips need a more frequent refreshing operation. Therefore, in the near future, time and energy cost on DRAM refreshing will be no longer trivial. In this paper, we propose DRAM Error Correction Pointer(ECP), an error-correction-manner framework, to reduce DRAM refreshes without data loss. We exploit the non-uniform feature of DRAM cells with respect to the data retention time. Compared with the conventional refreshing mechanisms, which refresh DRAM chips by the retention time of the leakiest cells, we refresh the chips much fewer times, and treat the not-in-time refreshed cells as fault elements. We use the structure of ECP as a fault tolerant element. By recording the data which are supposed to be written into the leaky cells in our DRAM-ECP structures, DRAM-ECP can significantly decrease refreshing frequency. When these data are to be read out, DRAM-ECP retrieves the data stored in ECPs and covers them to the corresponding position in the data row. Our experiments show that DRAM-ECP can reduce over 70%refreshing operations than the current refreshing mechanism and also get significant energy saving.

关键词： DRAM refreshing error correction DRAM-ECP counting bloom filter retention time

Theoretical simulation of chromatographic separation based on random diffusion in the restricted space

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Science China Chemistry 2016年第7期59卷 824-829页

作者： Jianwei Zhao Yinlu Sun Yajun Gao College of Materials and Textile Engineering Jiaxing UniversityJiaxing 314001China College of Chemistry Liaoning UniversityShenyang 110036China State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210023China

The diffusion behavior of particles in the chromatography is a fundamental issue of chromatographic dynamics. The understanding of the diffusion behaviors is particularly critical to optimize the operation conditions, improve the chromatographic performance and design a new separation device. Many of the present simulations focus on chromatographic thermodynamics, and very few aim at the overall diffusion and separation process. In order to dynamically trace the trajectory of the diffusing particles and to perform simulations of the whole chromatographic process, we have developed a model based on the framework of random walk in the restricted space and performed the simulation of a single particle diffusion in the gas chromatography. The simulation parameters were determined by comparing with the experimental data. The elution profiles of n-alkanes under different flow rates were accurately simulated with the method. The results show that the relative difference between the measures and the simulations are less than 2% and 10% for the retention time and the peak width, respectively. The simulation method shows great significance for the optimization of separation conditions and the development of novel technologies of chromatographic separation.

关键词： random walk restricted space gas chromatography diffusion retention time peak width

Prediction retention timein short gradient elution for peptide separation

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Prediction retention timein short gradient elution for pepti...

Separation of Aromatic Carboxylic Acids in IC and the Study on the Relationship Between retention Behavior and Electrostatic Potential

中国化学会第22届全国色谱学术报告会及仪器展览会

作者： Pengyuan Yang Xiaohui Liu Department of Chemistry Fudan Univ Institute of Biomendical Sciences Fudan Univ

＜正＞Theoretically prediction of retentiontime（RT） of peptides separated by nano-RPLC systems will be very helpful for LC-MS/MS based peptide identification and quantification analysis,and for transferring a gradient method to between instruments,columns,*** had an assumption that with an appropriate gradient elution method,peptides can get a sufficient equilibration on column and thus we can calculate the concentration of acetonitrile（ACN） for peptide eluting more precisely which can help us for further prediction study.

关键词： retention time short gradient peptide separation

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Chinese Journal of Structural Chemistry 2010年第4期29卷 641-646页

作者：王艳花韩小江陈雪松李立朱岩 College of Biology and Environment Engineering Zhejiang Shuren University Department of Chemistry Zhejiang University

A method has been developed for separation of 20 kinds of aromatic carboxylic acid using anion-exchange chromatography. A Dionex IonPac AS9-HC guard column （250mm×2mm） was used with a 9mmol/L sodium carbonate solution containing 50% （v/v） acetonitrile as eluent. A set of retention time data has been obtained using a conductivity detector DS6. Furthermore, geometrical optimization and electrostatic potential calculation of 20 kinds of aromatic carboxylic acid have been performed at the HF/6-31G＊ level of theory. A number of statistically-based parameters derived from molecular surface electrostatic potential have been obtained. Linear relationship between retention time and structural parameters has been established by multiple regression method. The result shows that parameters derived from electrostatic potential Vs ＋, Vs -, П together with the dipole moment μ can be well used to express the quantitative structure-retention time of this kind of aromatic carboxylic acid. Good predictive capability has also been demonstrated. The result has provided a framework which further proves the general applicability of this electrostatic potential parameter set to a great extent,and with which the ion chromatographic adsorption mechanism can be investigated.

关键词： Ion chromatography retention time QSRR molecular electrostatic potential aromatic carboxylic acid

Quantitative Structure-retention Relationship Study of Volatile Components from Rosa Banksiae Ait

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Chinese Journal of Structural Chemistry 2012年第8期31卷 1201-1211页

作者：程利平包晓净王根礼 School of Chemical and Environmental Engineering Shanghai Institute of Technology

In the present study,（QSRR） study had been carried out for volatile components from Rosa banksiae *** on various quantum-chemical and physicochemical descriptors derived by B3LYP *** build QSRR models,a multiple linear regression （MLR） stepwise method was *** generated models have good predictive ability and are of high statistical significance with good correlation coefficients （R2≥0.734） and p values far less than *** results indicated that the application of the models,especially the prediction of GC retention time and linear retention index of volatile components from Rosa banksiae Ait.,will be *** models contribute also to the identification of important quantum-chemical and physicochemical descriptors responsible for the retention time and linear retention *** was found that the shape attribute （ShpA） and logP value play a vital role in determining component’s GC retention time and linear retention index which increase with the lipophilicity of volatile *** larger the shape attribute of analyte is,the larger the deformability is,the stronger the interaction between analyte and stationary phase is,and the longer the GC retention time is,the larger the linear retention index *** importance of E HOMO,q＋,and SEV is also embodied in models,but they are not dominant.

关键词： Rosa banksiae Ait. quantitative structure-retention relationship (QSRR) retention time linear retention index density functional theory (DFT)