Titration devices: 1 - pipette;
2 - burette.
Titration (titrimetry) is a quantitative analysis method based on measuring the volume of a reagent solution with a precisely known concentration that has reacted with a specific volume of an analyte solution. The volume of the solution being analyzed, which is in a conical flask, is gradually added to the measured pipette (Fig., 1) from the burette (Fig., 2) the reagent solution titrated (that is, with a known concentration). Titration is complete when the analyte is fully reacted with the added reagent. The end of the titration is set by changing the color of the corresponding indicator (see) or by other methods. On the scale of the burette determine the volume of reagent solution, followed by titration. The normal concentration of C1 and the titer T of the analyte solution (see Concentration) is calculated by the formulas:
where υ 2 and C 2 are the volume and normal concentration of the reagent solution, respectively, and E is the equivalent weight (see) of the analyte. This titration method is called direct titration. Sometimes it is necessary to apply a reverse titration. In this case, an excess, accurately measured volume of the corresponding reagent solution (reagent I) is added to the volume v1 of the analyzed solution. The unreacted excess of this reagent is titrated with a solution of another reagent (reagent II). The normal concentration of C1 and the titer T of the solution of the analyte is calculated by the formulas:
where υ 2 , υ 3 and C 2 , C 3 are the volumes of titrated solutions of reagents I and II and their normal concentrations, respectively.
About the use of titration in laboratory and clinical practice - see. Neutralization method, Oxydimetry, Deposition methods.