Overview on the Gran and other linearisation methods applied in titrimetric analyses

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Titrimetry

Background:

• Traditional linearisation methods in titrations can introduce significant errors.
• Existing methods may have limitations in terms of titrant addition and proximity of points to equivalence volume.
• Potentiometric titrations often require accurate determination of electrode characteristics.

Purpose of the Study:

• To present modified, extended, and generalised linearisation methods for titration analysis.
• To improve the accuracy and scope of equivalence volume evaluation in titrations.
• To introduce new methods for cyanide determination and complexometric/precipitation titrations.

Main Methods:

• Modified Gran I method using an approximation for improved equivalence volume evaluation.
• Extension of pH-static titration to complexometric and precipitation titrations.
• Generalisation of the Ni method to diverse acid-base systems using Simms' constants.
• Simulating procedures based on iterative computer programs for data generation.

Main Results:

• The modified Gran I method avoids errors, allows greater titrant addition, and uses points closer to the equivalence volume.
• Avoids the need for prior determination of electrode characteristics.
• pH-static titration extended to new cyanide determination methods and a three-component precipitation titration.
• Ni method extended to various acid-base systems.

Conclusions:

• The presented linearisation methods offer significant improvements in accuracy and applicability for various titration types.
• These methods provide a robust framework for analytical prescriptions without simplifying assumptions.
• The study contributes novel approaches to chemical analysis, particularly in potentiometric and complexometric titrations.