University Chemistry ›› 2017, Vol. 32 ›› Issue (7): 88-92.doi: 10.3866/PKU.DXHX201701001

• Self Studies • Previous Articles    

A Buffer with Constant Buffer Capacity in a Wide pH Range

Yan-Ni ZHANG1,*(),Xiao SHANG2,Hui WANG2,Xuan-Feng YUE2,*()   

  1. 1 Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry, Shaanxi Normal University, Xi'an 710062, P. R. China
    2 Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Shaanxi Normal University, Xi'an 710062, P. R. China
  • Published:2017-06-27
  • Contact: Yan-Ni ZHANG,Xuan-Feng YUE;
  • Supported by:


The buffer, composed of 6 weak acids with the different pKa(citric acid, phosphoric acid, boric acid, hydrazine, dimethylamine cation and diethylamine cation), can work well in the pH range of 2-12.By manipulating the combination of the concentrations of the weak acids, a constant buffer capacity of 0.7C average can be obtained in the entire pH range.All the precise calculations and plottings were conducted via the Sigmaplot software.

Key words: Constant buffer capacity, Wide pH range, pH buffer system


  • G64