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Summary Gas chromatographic retention indices for 47 C5 to C8 alkenes on OV-101 dimethylsilicone at 50 and 70 °C were determined within a standard deviation of 0.3i.u. Data obtained on
OV-101 are compared with those measured on squalane. The comparison of the retention index and dl/dT values from both columns
is presented as linear regression equations with correlation coefficients greater than 0.98. 相似文献
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Summary The separation of C1–C4 nitroparaffins on SE-30, PEGA and Porapak R stationary phases was investigated. The nitroparaffin mixture was obtained from a real technological process. The best separation was achieved on Porapak R at 190°C. The fact that each peak obtained from this column corresponded to a single compound was checked by utilizing the linear relationship between the peak widths and the adjusted retention times (t
R
). Peak identification was carried out using the chromatographic data only, with help of plots of log t
R
vs. carbon number and log t
R
vs. boiling point; some of the results were also confirmed with comparing the retention times with those of pure substances and IR investigation of the collected chromatographic fraction. 相似文献
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Summary The separation of C1–C4 mononitroalkanes on four wall-coated glass open tubular (capillary) columns (liquid phases: OV-101, Ucon-LB-550X, NPGS and Carbowax 20M) was investigated. Retention indices were determined and the influence of the different factors (analysis temperature, method of determining the gas holdup time and the nature of the stationary phases) on their reproducibility were studied. Linear regression equations permit the pre-calculation of the retention indices of C1–C4 mononitroalkanes from their properties on all liquid phases studied. 相似文献
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Summary The separation of C1–C4 alkyl tert-butyl ethers with the general formula (CH3)3C–O–R (R-alkyl substituent) on fused-silica capillary columns coated with dimethylsilicone and cyanopropylmethylsilicone stationary phases was investigated. Retention indices were determined at two temperatures in order to understand their chromatographic behaviour. The respective standard deviations were 0.3 and 0.5 i.u. 相似文献
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Boneva MP Christov NC Danov KD Kralchevsky PA 《Physical chemistry chemical physics : PCCP》2007,9(48):6371-6384
Here, we investigate experimentally and theoretically the motion of spherical glass particles of radii 240-310 microm attached to a tetradecane-water interface. Pairs of particles, which are moving toward each other under the action of lateral capillary force, are observed by optical microscopy. The purpose is to check whether the particle electric charges influence the particle motion, and whether an electric-field-induced capillary attraction could be detected. The particles have been hydrophobized by using two different procedures, which allow one to prepare charged and uncharged particles. To quantify the hydrodynamic viscous effects, we developed a semiempirical quantitative approach, whose validity was verified by control experiments with uncharged particles. An appropriate trajectory function was defined, which should increase linearly with time if the particle motion is driven solely by the gravity-induced capillary force. The analysis of the experimental results evidences for the existence of an additional attraction between two like-charged particles at the oil-water interface. This attraction exceeds the direct electrostatic repulsion between the two particles and leads to a noticeable acceleration of their motion. 相似文献
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