A rapid and rapid method to quantify poly (γ-glutamic acid) content via copper ion complexation

Area of Science:

• Biochemistry
• Analytical Chemistry

Background:

• Quantifying poly (γ-glutamic acid) (γ-PGA) is challenging due to impurities in biological samples.
• Existing methods for γ-PGA determination have limitations in speed and accuracy.

Purpose of the Study:

• To develop a rapid and accurate method for quantifying γ-PGA content.
• To overcome the limitations of current γ-PGA determination techniques.

Main Methods:

• Utilized the complexation reaction between γ-PGA, common impurities (glucose, glutamic acid, proteins), and copper ions.
• Observed that only γ-PGA forms a precipitate with copper ions, allowing for quantitative analysis.
• Compared the accuracy and precision of the copper ion method with UV and weighing methods.

Main Results:

• The copper ion complexation method demonstrated a linear correlation between γ-PGA content and precipitate amount.
• Achieved high accuracy (95.82%) and precision (99.29%) with the copper ion method.
• The developed method significantly outperformed UV and weighing techniques in accuracy and precision.

Conclusions:

• The copper ion complexation method provides a robust and reliable approach for determining γ-PGA content.
• This method is suitable for quantifying γ-PGA in crude biological samples, offering a significant improvement over existing techniques.
• The simplicity and accuracy of this method suggest its widespread adoption for γ-PGA analysis.