ABSTRACT
Objective@#To establish a method for determination the S-phenylmercapturic acid in urine by dispersive solid-phase extraction using Humic Acid/Fe3O4 magnetic nanocomposite as adsorbent.@*Methods@#The 5 ml of urine samples were adjusted to pH 1.0 and extracted by Fe3O4@HA. Then the analytes were separated on EC-C18 capillary column and detected by HPLC-VWD. The S-phenylmercapturic acid was characterized by the retention time and quantified by peak area and external standard method.@*Results@#The standard curves of SPMA showed significant linearity between 0.04~1.00 mg/L (r=0.999 7) . The average recovery was 94.2%~102.4%. The intra-day and inter-day precisions (RSD) were 2.9~6.7% (n=6) and 3.1~7.5% (n=6) respectively. The detect limit of SPMA was 0.012 g/L (S/N=3) .@*Conclusion@#This method is simple, rapid, sensitive and accurate. It is applicable for determination of SPMA in the urine of works who were exposed to benzene.
ABSTRACT
Objective@#To establish a method for determing the trichloroethylene(TCE)and trichloroethanol(TCOH)in blood samples by liquid-liquid extraction-gas chromatography with electron capture detector.@*Methods@#With this method,ether was used as extraction solvent and trichloromethane was used as an internal standard. The whole blood sample was extracted with ether, and dehydrated by anhydrous sodium sulfate. Then the analytes were separated on HP-5 capillary column(30m×0.32mm×0.15μm)and detected byECD.The retention time was for qualitative analysis and the internal standard was for quantitation.@*Results@#The standard curves of TCE and TCOH showed significant linearity between 95.5μg/L-7640.0μg/L(r=0.9997)and 19.0μg/L-1520.0μg/L(r=0.9992). The average recovery was 95.5%-103.6%.The intra-day and inter-day precisions(RSD)were 2.5%-6.8%(n=6)and 1.6%-4.3%(n=6) respectively. The detect limit of TCE and TCOH were 2.10 μg/L and 0.56μg/L(S/N=3)respectively.The blood can be kept 7 days at-20℃ refrigerator without significantly loss.@*Conclusion@#This method is proved to be simple,practical and highly sensitive. It can satisfy the request for the determination of blood samples of humans exposed to TCE.
ABSTRACT
Objective To study the chemical constituents of Dysosma pleiantha.Methods Acidic resins were precipitated by 1% HCl solution, then the constituents were isolated and purified on repeated silica gel column.They were identified and structurally elucidated by physicochemical constants and spectral analysis.Results Ten compounds were obtained and identified: podophyllotoxone (Ⅰ), dehydropodophyllotoxin (Ⅱ), podophyllotoxin (Ⅲ), 4′-demethylpodophyllotoxin (Ⅳ), 4′-demethyldehydropodophyllotoxin (Ⅴ), kaempferol (Ⅵ), quercetin (Ⅶ), n-hexadecanoic acid (Ⅷ), ?-sitosterol (Ⅸ), and daucosterol (Ⅹ).Conclusion Compound Ⅴ is a new compound, compounds Ⅷ-Ⅹ are first separated from the plants of Dysosma Woodson and other compounds are first separated from D.pleiantha.