Study On The Determination Of Some Natural Products And Some Trace Environmental Organic Contaminations By High-performance Liquid Chromatography And Ion Chromatography Coupled With Mass Spectrometry

Liquid chromatography coupled with mass spectrometry (LC/MS) is one of the most important tools for the analytical chemistry, and, it is one of the widely used techniques in the analysis of the natural products and the environmental organic contaminations. In this dissertation, a series of rapid, sensitive and accurate LC/MS analytical methods were established for the determination of soyasaponins in hypocotyls, soyasaponins and the Tripterygium wilfordii Hook. f. (TWHF) bioactive compounds in human blood, and trace chlorophenolics compounds in water and clam tissues, and through detailed examination for the behavior of liquid chromatographic thermodynamics and kinetics. It includes the following aspects:A rapid qualitative and quantitative method was established for the characterization and determination of soyasaponins in hypocotyls by ultrasound-assisted extraction, high performance liquid chromatography coupled with electrospray ionization mass spectrometry (LC/ESI-MS) and tandem mass spectrometry (LC/ESI-MS-MS). A mass spectrometry qualitative assay was also established by direct injection ESI-MS and ESI-MS-MS. This method could simultaneously determined more than 50 compounds of group A, group B and group DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H- pyran-4-one) soyasaponins in hypocotyls. The limits of the quantification for the soyasaponins were as low as 2.0-4.0 ng/mL.A LC/ESI-MS-MS method was developed and validated for the determination of soyasaponins Ba and Bb in human serum using glycyrrhizin as an internal standard (I.S.). Soyasaponins Ba and Bb were extracted by C₁₈ solid-phase extraction (SPE), and detected in the multiple-reaction monitoring (MRM) mode. The calibration curves were linear (r²> 0.991) in the concentration range of 0.5-100.0 ng/mL with a lower limit of quantification of 0.5 and 0.3 ng/mL in human serum for soyasaponins Ba and Bb, respectively. The mean recoveries of soyasaponins Ba and Bb were 95.6% and 90.0%, respectively.By extraction with ethyl acetate, and detection with negative atmospheric pressure chemical ionization (APCI) and ion trap tandem mass spectrometry in MRM mode, a LC/MS-MS assay was developed and validated for the quantitative determination of triptolide, tripdiolide and celastrol in human whole blood using prednisolone, dexamethasone acetateand hydrocortisone, respectively, as an I.S.. The calibration curves were well linear (r-2>0.995) in the concentration range of 1.0 - 100.0 ng/mL in human whole blood with a limit of quantification of 0.5, 0.5 and 1.0 ng/mL, respectively.A LC/APCI-MS method in the selected ion monitoring (SIM) mode was developed for the determination of four TWHF alkaloids (wilfordine, wilforine, wilforgine and wilfortrine) in human serum using aconitine as an I.S. after the analytes were extracted with ethyl acetate and cleaned up by SPE. The results indicated that the calibration curves were linear (r-2>0.995) in the concentration range of 1.0 - 100.0 ng/mL in human serum with a limit of quantification of 1.0 ng/mL each. The mean extraction recoveries for them were between 82.1 and 94.2%.An ion chromatography mass spectrometry equipment (IC/MS) was successfully assembled by ourselves by connecting in series a conductance suppressor after column between the ion chromatograph and the mass Spectrograph, which could change the pH value at the post-column eluent and decrease the content of the involatile inorganic salt in the eluent by adjusting its current, and well solved the suppressing and quenching problems of the mass spectrometric signal with the connection of IC and MS. A novel separation and analytical method was developed for the determination of trace chlorophenolics compounds in water and clam tissues by IC/APCI-MS in the negative mode. The method comprised of a SPE extraction technique, membrane technique and the sensitive and selective detection technique of the mass spectrometry. The results indicated that the limits of quantification are 0.005 -0.048 ng/mL in water, and 0.05- 0.50 ng/g in clam tissues.