| This paper can be divided into two parts, and the first part is the study of the speciation analysis of chromium in Traditional Chinese Medicines (TCMs) water decoction. Contamination of TCMs with heavy metals has caught great concern worldwide. The existance of heavy metals not only influence the quality and safty of Chinese herbal medicines, but also will become a major obstacle to the herbal products to enter the international market, therefore it is important to control the concentration of heavy metals which is of great toxicity in order to maintain the quality of TCMs. In Chinese pharmacopoeia, no relative check item about heavy metal chromium is set, while the corresponding toxicity of every valence of heavy metal differs greatly, therefore establishing a speciation analytical method for chromium has great significance to maintain a correct assessment of the toxicity of chromium in TCMs and the safety of TCMs, only in this way can the presence of chromium and the pollution levels will be evaluated.In the first part of this study, the concentration of total chromium in8mineral TCMs have been assessed by the method which had already been established by our laboratory, while the toxicity and the concentration of total chromium didn’t match with each other, therefore establishing the speciation analysis method was needed. In this paper, a simple, fast pre-treatment method for speciation analysis was estabished. In the pre-treatment procedure, the trifluoroacetylacetone(TFA) buffer solution can be obtained by mixing the trifluoroacetylacetone (TFA) with cyclohexane, then added the buffer of acetic acid-sodium acetate, the volume ratio of these three agents were1:2:2. Cr (Ⅲ) reacted with TFA in water bath of70℃to form a volatilizable chelate CrⅢ(TFA)3which could be volatilised totally in the GFAAS procedure in order to separate chromium (Ⅲ) and chromium (Ⅵ), then the concentration of chromium (Ⅵ) could be obtained by using lmg/mL magnesium nitrate as matrix modifier. Method validation results showed:the linearity of this method ranged from0ng/mL to100ng/mL, the detedtion limit was0.63ng/mL, the limit of quantitation is2.1ng/mL and the average spiked recoveries of the5kinds of TCMs’water decoction were96.8%～105.8%. This method was suitable for the speciation analysis of chromium in5kinds of TCMs water decoction. The total concentration of chromium in the water decoction was also detected by the method established by our laboratory in order to give an accurate assessment of total chromium and hexavalent chromium in water decoction. The results showed that:the contents of Cr (VI) in the eight minerals TCMs decoctions were far less than the calculated tolerable daily intake of EPA’s oral reference dose, so the contents of heavy metal hexavalent chromium that were decocted into the decoctions were very low and of less pollution, so the following healthy risk were limited.The second part is the study of the concentration of isorhapontigenin in mice plasma. In this section a LC-MS/MS method was established for the analysis of the concentration of isorhapontigenin in mice plasma, the pre-treatment method of the plasma:the plasma sample was mixed with equal volume of pH3.2hydrochloric acid and extracted by ethyl acetate, the organic phase was dried by the nitrogen and then dissolved with mobile phase. The analytical column was Shim-pack XR-ODS (2.3X75mm,3μm), the flow was0.2ml/min and the mobile phase was methanol (B) and water with0.1%formic acid (A) using gradient elute, the initial B was65%kept for0.3min, then changed to95%in0.5min and lasted for1.7min, then returned back to65%in0.1min and lasted for3.9min, the analysis used the multiple reaction monitoring (MRM) mode with the negative electrospray ionizaition and the precursor/product ionpair of m/z258.0/247.1for isorhapontigenin and m/z271.1/151.0for the internal standard naringenin. The test result showed:the calibration curve was linear in the range of5ng/mL～20μg/mL (r=0.9993) for isorhapontigenin. The average recoveries of low, medium, and high concentrations were98.9%,99.7%and104.2%. The linearity relationship of low, medium and high doses with AUC(0-t), AUC(0-∞) and Cmax were analysis by using the power function model, the results showed AUC(0-t), AUC(0-∞) and Cmax had a linear relationship with the doses of isorhapongenin within40mg/kg and160mg/kg by oral administration. Thus isorhapongenin had linear pharmacokinetic characteristices with the doses in the range of this trial. The result of isorhapontigenin pharmacokinetic study in mice showed:the peak time (Tmax) of low, medium, high doses isorhapontigenin in mice was0.103±0.053h,0.125±0.102h,0.139±0.101h; the peak concentration (Cmax) of low, medium, high doses isorhapontigenin in mice was8786.940±4233.021μg/L,13173.319±2480.959μg/L,16471.568±2445.476μg/L; the elimination half-life (t1/2) of low, medium, high doses isorhapontigenin was1.253±0.154h,1.886±0.741h,1.619±0.630h; all the results above showed that the concentration of isorhapontigenin in mice can reach the peak and metabolized quickly, so it cannot maintain the effective concentration for a long time. For the good pharmacological activities of isorhapontigenin, there is a must to do a furture modification for the structure of isorhapontigenin and research an appropriate method of administration and dose form in order to maintain a relatively stable concentration of effective treatment and increase the druggability of isorhapontigenin. The study of this paper has a guiding significance for the druggability of isorhapontigenin. |
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