A low-cost automated titration system for colorimetric endpoint detection

Area of Science:

• Analytical Chemistry
• Instrumentation Science

Background:

• Traditional titration methods for spectrochemical analysis often rely on manual endpoint detection, which can be subjective and prone to analyst bias.
• Visual colorimetric endpoint determination lacks precision and accuracy, especially across different analysts.

Purpose of the Study:

• To develop an automated titration system for accurate and precise colorimetric endpoint detection in spectrochemical titrations.
• To evaluate the performance of the auto titrator compared to traditional manual titration methods.

Main Methods:

• A cost-effective auto titrator was constructed using a Raspberry Pi single-board computer, 3D-printed parts, and a spectral sensor.
• The system's performance was validated through standard water hardness determination.
• Inter-day, intra-day, inter-instrumental, and intra-instrumental studies were conducted to assess accuracy and precision.

Main Results:

• The auto titrator demonstrated superior performance compared to manual titration, irrespective of analyst experience.
• The system consistently produced accurate and precise endpoint detection results.
• Validation studies confirmed the reliability and reproducibility of the automated system.

Conclusions:

• The developed auto titrator system offers a reliable, accurate, and precise alternative for colorimetric endpoint detection.
• Automation effectively removes subjective bias associated with visual color perception in titrations.
• This inexpensive system provides a valuable tool for improving analytical chemistry workflows.