Optimix Technology And Its Application In The Analysis Of Complex Mixtures

As one of the toughest subjects in morden sciences, the analysis of complex mixtures has posed a great chanllege to the current determination techniques, which not only refers to the assay of the natural medication and environmental samples with complex matrix, but also includes those critical pair compounds scarcely be discriminated by conventional means. Therefore, accurate determination methods and separation techniques with high efficiency are in great need. However, neither the classic chromatographic method nor multi-dimensional chromatography could satisfactorily optimize the HPLC separation of complex mixtures.Utilizations of mixed stationary phase can be dated back to the 1960s, which almost exlcusively exploited the separation characteristics of the mixed phase columns, yet hardly could be defined as systematic HPLC optimization strategies. In this paper, based on the application of mix-phase columns, we propose Optimix technology, a general, systematic and simple optimization strategy for HPLC separation of complex mixtures. By mixing two single stationary phases with different selectivities, and plotting the retention times of each analyte against the ratio of the stationary phases, the optimum mix-phase column demonstrated a superior selectivity and outstanding separation performance. Compared to traditional"trial and error"experiments and 2D-LC technology, Optimix technology is no time-consuming and easy to achieve, showing a promsing prospect in HPLC analysis, especially separation of complex mixtures. This research mainly focoused on the application of Optimix technology on multi-analyte assay, interference elimination, separation of isomers and compounds related by structure. The primary conclusions are as follows.1. By using a series of Mix-phase columns of which selectivity displays a systematic changing pattern, one may change the separation of analytes in a methodical way, achieving a balanced separation for all critical pairs.2. Impurities and target compounds could be totally separated on the optimized Mix-phase column, and thus be accurately identified and quatitified. The chances of misjudgement brough by interference peaks were decreased remarkably.3. As the best composition of the mix-phase was obtained, the slight structural differences between the target substances were distinguished. The optimum mix-phase column demonstrated a superior selectivity and a suitable performance for the separation of structurally related substances and isomers, and could be an excellent alternative to conventional revered-phase columns. The SPE-HPLC and SPE-LC/MS/MS methods for the determination of triazine herbicides in waters with the Mix-phase SCX/C8 column were described. The PEP cartridge was selected for sample pre-preparation. The proposed methods were validated with respect to linearity, limits of detection and repeatabilities and satisfactory results were obtained.The methods for quality control purposes can be applied in the simultaneous determination of multi-residues of triazine herbicides in surface water as well as sauce water for drinking use.