| Traditional Chinese medicine (TCM) is a great treasure-house of the Chinese nation. Recently, under the influence of back to nature, searching for natural medicines is attracting more and more attention, while TCM has aroused the concern of all countries in the world for its rich resources, unique effects, fewer side effects, etc. Moreover, the acceptance of natural medicine in western developed countries provides the development of modernization of TCM an unprecedented opportunity. Quality control of TCM and its pharmacokinetics are the two aspects of modernization of TCM. Therefore, Using modern science and technology to clarify the role of its active compounds and their action mechanism and control their absorption, distribution, metabolism and excretion in vivo, as well as to ensure the safety and effectiveness, are the primary tasks of modernization of TCM. Hyphenated chromatography techniques which combine the information of chromatography and spectroscopy or mass spectrometry, provide a rapid, accurate, reliable and sensitive method for analysis of TCM and biological samples. Thus, based on the current development platform of chromatography, we have carried out the following innovative works:(1) A SPE method based on mixed hemimicelles of cetyltrimethyl ammonium bromide (CTAB) on silica coated magnetic nanoparticles (MNPs) is developed for extraction and preconcentration of compounds from the biological samples. We selected rhein and emodin which are the major active anthraquinones of rhubarb as model analytes. A high performance liquid chromatography-fluorescence detection (HPLC/FLD) method was developed for the determination of rhein and emodin in serum and urine samples. The main factors influencing the extraction efficiency including the amount of surfactant, the concentration of MNPs, the shaking time and the desorption ability of organic solvents were investigated and optimized. Good linearities for all calibration curves and accuracy were obtained, and the limits of detection (LODs) for rhein and emodin were 0.2 and 0.5 ng/mL in urine samples and 7 and 10 ng/mL in serum samples, respectively. Satisfactory recoveries (92.76-109.90%) in the biological matrices were achieved.(2) In this work, a simple and sensitive micellar liquid chromatography (MLC) method is proposed for the determination of cryptotanshinone (CT) and tanshinone IIA (TS) in herbal medicine preparations and biological samples. No extraction step is required. CT and TS are the major active compounds contained in traditional Chinese medicine Radix salvia miltiorrhiza. Due to their powerful pharmacological activities, much attention has been attracted. A micellar mobile phase of 0.15 M SDS and 8% n-butanol was used. No interferences were caused by proteins or endogenous compounds in herbal medicine preparation, urine and serum samples. Good Linearities (r2 > 0.998) for all calibration curves were obtained, the intra-day and inter-day precisions were less than 2.7% and 3.5% for CT and TS, respectively. The limits of detection (LODs) for CT and TS were 12.5 and 15 ng/mL in micellar solutions, 18 and 25 ng/mL in urine samples and 20 and 30 ng/mL in serum samples, respectively. Satisfactory recoveries in the biological matrices were achieved in the 96.97–101.86% and 97.48–103.14% range for CT and TS, respectively.(3) A new magnetite nano-beads based microwave-assisted (MBMAE) technique was developed to improve the extraction of bioactive compounds from plant tissues, Scutellaria baicalensis Georgi and its herbal preparations were taken as application examples. Influencing factors were studied in detail. The new method is advantageous. In the presence of magnetite beads, 40 s microwave irradiation, was sufficient for carrying out the whole extraction process. Furthermore, it yields a higher extraction efficiency compared with the conventional microwave extraction technique and a lower consumption of organic solvent is needed. The extracts were analyzed by HPLC-ESI-MS. For bioactive flavones compounds of baicalin, baicalein and wogonin, the recovery was in the range of 97.6–101.4% with relative standard deviation lower than 2.5 % by the proposed procedure. The limits of detection were 0.05, 1.0 and 2.0 ng/mL for wogonin, baicalein and baicalin, respectively. The proposed method can be successfully applied to the analysis of other biological practical samples. |
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