关键词: 伪劣钛白粉, 络合滴定法, 丙三醇, 水解抑制剂, 混合指示剂三元体系

Abstract: Illegal enterprises often mix calcium carbonate，lithopone，kaolin and other illegal additives in titanium dioxide. Based on this phenomenon，the selective complexometric titration method for detection of titanium content has been estab- lished.The method used concentrated sulfuric acid and ammonium sulfate to decompose the sample，and used glycerol as the hydrolysis inhibitor of TiO2+.The pH of sample solution was in the range of 2.0~4.0.The excessive EDTA was added to com- plex TiO2+ and other metal ions.A mixed indicator ternary system was set up with xylenol orange（XO），methyl thymol blue （MTB），and sodium dodecyl sulfate（SDS）.Excessive EDTA was back titrated with zinc chloride standard solution.TiO- EDTA was selectively decomposed by sodium potassium tartrate.The released EDTA was titrated with zinc chloride standard solution again.The standard addition recovery of method was at 98.78%~100.18%，and the relative standard deviations（RSD） was at 0.10%~0.78%.The method was simple and easy to operate，and the end point of the method was clear and sharp，and it was suitable for the determination of titanium dioxide content in the inferior quality titanium dioxide.

Key words: inferior titanium dioxide, complexometric titration, glycerol, hydrolysis inhibitor, mixed indicator ternary system