Objective:To improve and optimize the determination methods for 15 chemical sun-screening agents in cosmetics by HPLC described in Hygienic Standard for Cosmetics (2007 edition) to enhance the quality control of limited chemical sun-screening a-gents in cosmetics. Methods:The samples were extracted using the improved mixed liquor. The detection was performed on an Accur-asilC18(250mm×4.6mm,5um)analyticalcolumn,themobilephasewasmethanol-tetrahydrofuran-water(adjustingpHto2.60 with acetic acid) with gradient elution, the flow rate was 1. 0 ml·min-1 , the column temperature was 25℃,and the detection wave-length was 311nm. Results:The method showed good linear relationship and the correlation coefficient was above 0. 999 5, the detec-tion limit was 1. 9-18. 7 ng, and the average recovery was within the range of 97. 5%-113. 7% with RSD of 0. 85%-1. 56%(n=9). Conclusion:The improved method is reliable, which is the effective optimization and complement for the determination methods of chemical sun-screening agents in cosmetic described in Hygienic Standard for Cosmetics (2007 edition).

AIM To establish a UV spectrophotometry for the determination of arsenic in Jiuji Xingjun Capsules. METHODS Arsenic was transformed into hydrogen arsenide,then silver diethyldithiocarbamate was reduced for colloid silver by hydrogen arsenide,its absorbance was determined at the wavelength of 507 nm. RESULTS The linearity range of curve was 0.5-4.5 ?g?mL -1 ( r =0.999 5, n =7),The average recovery was 100.11 % ( RSD =1.64 T《B》 % , n =15). CONCLUSION This method is rapid and accurate.

AIM: To obtain a high and stable expression analog of human basic fibroblast growth factor by genetic engineering. METHODS: The cysteins 78 and 96 of natural hbFGF polypeptide was substituted with serines by means of site-directed mutagenesis. Using pET- 3c as vector, the mutated polynucleotide was cloned and then transferred into BL21 (DE3)plysS. After induction by IPTG, the analog was obtained and analyzed by SDS - PAGE. RESULTS: After purification the form of soluble mutant increased remarkably but the forms of dimmer and higher multimer were reduced greatly to no more than 8% of the total recombinant protein. By MTT assay, the analog showed the same biological activity. This new analog represented a desirable complementation for native hbFGF to develop pharmaceutical drug in clinical use. CONCLUSION: Substitution of certain amino acids of polypeptide without altering native protein' s bioactivity to get the analog is an effective means to increase stability of foreign protein and its solubility in E. coli.