High Performance Liquid Chromatography Negative Peak Phenomenon And The Measurement Of Replacement And In The Determination Of The Application

Negative peaks often appeared in HPLC determination, and there was a certain linear relationship between negative peaks and the amount of the corresponding compounds. The law of negative peaks in Chromatography can be used as an indirect chromatographic detection method in the analysis and determination of samples, and those weak or non responsed compounds would be detected in the form of negative peaks by photometric detector through adding the responsed compounds (background reagents) to the mobile phase. This HPLC-indirect photometric detection method was effective to detect those compounds. The phenomenon of negative peaks can be explained by the stoichiometric displacement theory. The sample molecules with no or weak UV absorption can displace the molecules with strong UV absorption adsorbed on the stationary phase and make them return to mobile phase in chromatographic separation process when mobile phase contained the molecules with strong UV absorption. So the concentration of the molecules with strong UV absorption decreased and the negative spike (weak absorption peaks) was detected by detector. The mensuration of negative peaks in chromatography reflected substances replacement in chromatographic separation process, and supported the stoichiometric displacement theory at experimental determination aspect. The determination of negative peaks in HPLC was studied systematicly in the research, and the content was divided into five chapters.Introduction. Through studying related literatures, the history and current situation of research and application about the phenomenon about negative peaks in HPLC and the stoichiometric displacement theory were summarized. The relationship between the determination of negative peaks and stoichiometric displacement was also described.The determination of methyl aliphatic ketones by negative peaks in RP-HPLC. The phenomenon of negative peaks in RP-HPLC and its production principle were studied, the stoichiometric displacement retention behavior of samples in the column was explained by the stoichiometric displacement action principle, and the content of the components in methyl aliphatic ketones was detected by the determination of negative peaks.Study on the relationship between negative peaks UV detection in RP-HPLC and the stoichiometric displacement theory. The production principle of negative peaks in RP-HPLC, and its relationship with the stoichiometric displacement theory were Studied.The qualitative and quantitative determination of dibenzyl disulfide, dibenzyl sulfide and bibenzyl in insulating oil, and the research about the determination of negative peaks in normal HPLC. Three compounds in insulating oil were analysised qualitatively and quantitatively by the determination of negative peaks in normal HPLC and GC/MS. The stoichiometric displacement relationship in normal adsorption chromatography was also studied.Study on the relationship between extraction distribution equilibrium theory and chromatographic retention behavior. UV absorption spectrum was used to characterized equilibrium distribution in extraction and compared with the chromatographic retention behavior to explain the competition adsorption and distribution equilibrium in chromatographic retention behavior.