贵州乌江水系枯水期河水硫同位素组成研究

对枯水期乌江及其主要支流河水的硫同位素组成进行了研究。河水SO4^2-的δ^34S值在-15．7‰～18．9‰之间，干流δ^34S值介于-3．7‰～0．0‰之间。主要支流河水的SO4^2-浓度和δ^34S值具有明显的区域性差异：上游碳酸盐岩地区支流河水SO4^2-浓度较高而δ^34S值较低，河水中的SO4^2-来源于煤中还原态硫的氧化、矿床硫化物氧化和大气降水；下游碳酸盐岩夹碎屑岩地区支流河水则相反，具有较低SO4^2-浓度和较高δ^34S值，河水中的SO4^2-来源于硫酸盐蒸发岩溶解、大气降水以及煤中还原态硫的氧化。干流的硫同位素组成显示枯水期河水中的硫酸盐主要来源于碳酸盐岩地区.

Application of liquid pre-column capillary electrophoresis technique to the study of interaction between drug enantiomers and human serum albumin

Based on the chiral separation of several basic drugs, dimetindene, tetryzoline, theodrenaline and verapamil, the liquid pre-column capillary electrophoresis (LPC-CE) technique was established. It was used to determine free concentrations of drug enantiomers in mixed solutions with human serum albumin (HSA). To prevent HSA entering the CE chiral separation zone, the mobility differences between HSA and drugs under a specific pH condition were employed in the LPC. Thus, the detection confusion caused by protein was totally avoided. Further study of binding constants determination and protein binding competitions was carried out. The study proves that the LPC technique could be used for complex media, particularly the matrix of protein coexisting with a variety of drugs.