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11.
Summary A computer interactive identification system is proposed which is based on the relationship between retention and molecular
properties such as the size and shape of polycyclic aromatic hydrocarbons (PAHs). This system offers an automatic analytical
process for liquid chromatography, providing a reliable identification of the separated components. The identification can
be further enhanced by the use of multiple detectors such as a multichannel UV detector. The system can be used for optimization
procedures, resulting in a highly automatic complex analytical system. 相似文献
12.
Summary The effect of silanol groups on three types of octadecylmodified column gels using heat-treated silicas by calcination has been studied by high-performance liquid chromatography. After heat-treating at 180°C, 500°C and 950°C, the silicas treated with octadecyldimethylchlorosilane were used for the measurement of physical and chemical analysis. From elemental carbon analysis data, the reactive silanol group concentrations, OH(s), were determined to be 2.0 in the 180°C treated silica, 2.1 in the 500°C treated silica and 1.6 in the 950°C treated silica, respectively (original silica: mean pore diameter 116 Å, specific surface area 298 m2/g, pore volume 1.22 ml/g, particle size 5.0 m). The separation factors, , of pyridine versus phenol were measured to be 0.79 on 180°C treated silica, 0.91 on 500°C treated silica and 1.98 on 950°C treated silica, using acetonitrile-water mixtures as the eluent. And then, on the basis of the physico-chemical and chromatographic data, the three types of octadecyl modified column gels using heat-treated silicas by calcination have been compared. 相似文献
13.
Calcium-induced alginate gel beads (Alg-Ca) containing alginate hydrolysate, such as the guluronic acid block (GB), was prepared and the drug release profiles were investigated under simulated gastrointestinal conditions. The addition of GB to Alg-Ca altered its rheological properties. A model drug (hydrocortisone) was incorporated at 78% of its theoretical yield within the dried Alg-Ca containing 5% GB and it was gradually released from the beads in JP XIV 1st medium for disintegration test (pH 1.2), while it was rapidly released with disintegration of the gel matrix in JP XIV 2nd medium (pH 6.8). In contrast, for Alg-Ca containing GB and chitosan, disintegration was not observed in these media and the drug release rate was markedly different. These results demonstrate that the release profiles of drugs incorporated into Alg-Ca can be controlled by adding these polysaccharides. 相似文献
14.
H. Ohta K. Jinno Y. Saito J. C. Fetzer W. R. Biggs J. J. Pesek M. T. Matyska Y. -L. Chen 《Chromatographia》1996,42(1-2):56-62
Summary The temperature-dependency of the separation of fullerenes in liquid chromatography (LC) has been examined using various alkyl bonded stationary phases. It has been found that a maximum retention temperature exists with long alkyl bonded stationary phases, whereas there is no similar effect with the newly synthesized alkyl bonded phases which have two phenyl groups at the base of the bonded phase. The interpretation of the retention behavior of fullerenes in the low temperature region on alkyl bonded stationary phases is discussed using information obtained by CP-MAS solid-state NMR spectroscopy and LC. 相似文献
15.
Y. Saito K. Jinno J. J. Pesek Y. -L. Chen G. Luehr J. Archer J. C. Fetzer W. R. Biggs 《Chromatographia》1994,38(5-6):295-303
Summary The chromatographic retention behaviour of two liquidcrystal bonded phases have been evaluated using polycyclic aromatic hydrocarbons (PAHs) as the probe samples in reversed-phase high performance liquid chromatography (RP-HPLC). The results clearly indicate that these phases have better planarity and shape recognition capabilities than commercially-avaialble polymeric octadecylsilica (ODS) phases whose strong planarity and shape selectivities were found earlier. It can also be concluded from the chromatographic observations that the shape recognition capability of these phases is dependent on both mobile phase composition and column temperature, but that the effect of mobile phase and temperature on the shape selectivity work independently. The retention behaviour can be explained by changes in the phase structure with changes of eluent composition and temperature. 相似文献
16.
Jinno K Sawada H Catabay AP Watanabe H Sabli NB Pesek JJ Matyska MT 《Journal of chromatography. A》2000,887(1-2):479-487
Packed column capillary electrochromatography (CEC), open-tubular CEC and microcolum liquid chromatography (LC) using a cholesteryl silica bonded phase have been studied to compare the retention behavior for benzodiazepines. It has been found that packed column CEC gives better resolution, faster analysis time than microcolumn LC for benzodiazepines maintaining similar selectivity except for some solutes which are charged species under the separation conditions. However, open-tubular CEC gave different selectivities to a larger extent for charged benzodiazepines from that which should be produced by the chromatographic properties of the cholesteryl silica phase. Charged species migration times are mainly influenced by electrophoretic mobility rather than the chromatographic interactions. 相似文献
17.
Kisuke Tabata Naoya Jinno Keiichi Noda Masahiko Hashimoto Kazuhiko Tsukagoshi 《Chromatographia》2012,75(7-8):423-428
Tube radical distribution chromatography (TRDC) uses an untreated open tubular capillary tube and a ternary mixture of solvents (water and hydrophilic/hydrophobic organic solvents) as a carrier solution. A model analyte mixture comprising 1-naphthol, 1-naphthoic acid, 1-naphthalenesulfonic acid, 2,6-naphthalenedisulfonic acid, and 1,3,6-naphthalenetrisulfonic acid was examined by the TRDC and capillary zone electrophoresis (CZE) systems that comprised mainly a capillary tube and a detector. In the TRDC system the elution order of analytes could be changed by altering the component ratios of the solvents, whereas in the CZE system the elution order was changed by altering the electroosmotic flow direction. The experimental data obtained provide clues about the features and utility of TRDC as a new separation method. 相似文献
18.
K. Jinno 《Chromatographia》1985,20(12):743-746
Summary The concept of retention prediction for the separation of phenylthiohydatoin-amino acid derivatives in isocratic reversed-phase liquid chromatography is described. A novel retention-solubility parameter, R, is defined, for the retention prediction strategy and the performance of this R value is evaluated by comparing measured and predicted retention data. Excellent agreement between these values were observed. It is concluded that the R value has a very high potential in describing the retention of phenylthiohydantopinamino acid derivatives withdifferent types of separation systems consisting of C-18, C-8 and phenethyl bonded stationary phases and various mobile phases. 相似文献
19.
20.
The computer-assisted liquid chromatographic system (MCASYST) is developed for automated identification and analysis. The system has six main functions: retention prediction system, liquid chromatographic data base system, automated identification system, optimization of separation conditions, data loading program from UV multichannel detector, and UV spectral data base system. The performance and potential of this MCASYST system is evaluated for toxic compounds identification in poisoned human fluids. 相似文献