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This Guide represents a valuable support for your work on automated determination of the pKa value. |
This Competence Guide covers relevant points to be considered when performing a pKa determination by spectrophotometric measurements. Learn more about
- Four key concepts:
To achieve accurate and correct results it is necessary to first understand how the pKa value is determined. Four specific concepts will support and guide you in the right direction. - Automated workflows:
The whole procedure can be fully automated by building an analytical system consisting of a spectrophotometer, a titrator, a liquid handling device, and an autosampler. - Calculations of the pKa value:
This section is dedicated to a comprehensive, step-by-step presentation of the involved calculations. - Tips and hints:
Selected tips and hints cover the most relevant points to achieve accurate and precise measurements.
Fully Automated pKa Determination Using LabX Laboratory Software
Full automation of the complete procedure including comprehensive documentation is one of the main goals of improving analytical workflows. In this application, a single analytical system for fully automated determination of the pKa value is achieved by connecting Titration Excellence T9, DispenSix Liquid Handler, InMotion Autosampler, and UV/VIS Excellence Spectrophotometer UV5.
Briefly, the compound of interest, e.g., an API (Active Pharmaceutical Ingredient), is dissolved in deionized water, and pH buffers, concentrated acids, and bases are automatically added in different ratios to prepare several solutions at predefined pH values. Subsequently, the UV/Vis spectrum of each solution is then measured.
