Stoichiometry Analytical High Performance Liquid Chromatography Overlapping Peaks Research And Application

Since 1960?years, chromatography has been extensively used to monitor atmosphere, water quality, soil, living things, and foods so on, and has played an important role in environmental monitoring and analysis.Now chromatography includes gas chromatography, high performance liquid chromatography, ion chromatography, supercritical fluid chromatography, capillary electrophoresis devoice .High performance liquid chromatography can analyze these compounds which have low volatility,or are easily decomposed after being heated,or are ion type or big molecule (molecular weight is more than 300 ),and these compounds account for about 80~/o in 3000,000 kinds of knowed compounds But high performance liquid chromatography often fell across the problem of chromatography peaks overlapping in analyzing complex system or multi- group system. It is difficult to exactly determine the contents of the compounds by peaks high or peaks area. This paper first attempts to resolute chromatographic overlapping peaks by two chemometrics methods-partial least squares method and ridge regression method , in which general principle ,methods,the key problems in operation and noticed proceedings etaL were primarily studied. At first lots of conditions which effect the stability of chmmatographic signals were researched in detail to ensure data good repetition.The experiments showed that a high precision steady power transformer can make the voltage well stability and a single but dual bumps to transport the mobile phase can reduce the unstable chances; standard solutions m~ made up as they are necessary; the capability bottles are well hermetic and don抰 stay over, which can prevent solvents from volating to make concentration changed; six bypasses valve to be used can lessen injection errors. The paper choosed the chromatographic overlapping peaks of o,mp- dihydroxybenzene as the research object. The chromatographic peaks of three dihydroxybenzene isomers occur seriously overlapping because their configurations and qualities are resembling.Experiniental conditions were optimized by homogeneous design method; experimental data were collected by Shiniadzu 6A liquid chromatography,N2000 chromatography data workstation and softwares to collect data the data were dealt with the excel application software and lots of signal data matrix were obtained and concentration data matrix were compiled, then these matrix were calculated by Partial Least Squares(PLS) or Ridge Regression. The study found that PLS isn't adapted to resolve the system but Ridge Regression can well resolve the chromatographic overlapping peaks and the results can satisfy analysis demands. In order to observe the influence factors, the time range and interval of collecting data points ,the number of mixed standard solutions ,concentration combination and ranges etal. were studied. The results showed that the time range and interval Of collecting data points are the key to resolve chromatographic overlapping peaks by Ridge Regression and the recoveries is between 92.000/a and 107.00%.