end point of titration
2.1mol/LKCI solution as ionic strength adjustor(ISA),the titrant is fed in a step way in equivalent Volumes to determine the pH value. After titration of weak base with strong acid,the volume of the titrant Vt is graphed in terms of Gran func- tion(V_0+V_t)×10~(-pH). The end point of titration can be derived by method of straight line extrapolation.
3.Pefloxacin mesylate was precipitated as PEFM TPB in HCl NaAc buffer solution (pH=5.2). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate was titrated with thallous sulfate standard solution in an alkaline solution. The disappearance of the incision of TPB on dE/dt=f (E) curve was used to indicate the end point of titration.
4.The result shows that the titration end point of cobalt with EDTA standard soultion as titrant was found to be sharp in the buffer solution of NH 3 · H 2 O-NH 4 Ac (pH=7.0) containing five drops TTZDBA solution. The end point occurs when the solution colour changes from purple red to bright orange, the end point is sensitive.
