Matrix effect in second-order data: determination of dyes in a tanning process using vegetable tanning agents

Area of Science:

• Analytical Chemistry
• Materials Science
• Textile Chemistry

Background:

• Vegetable tanning agents are crucial in leather production but present analytical challenges due to high absorbance.
• Accurate dye concentration monitoring is essential for optimizing the tanning process and ensuring leather quality.
• Matrix effects can significantly interfere with analytical measurements, impacting accuracy.

Purpose of the Study:

• To determine the concentration of three dyes during vegetable leather tanning.
• To investigate and address analytical challenges including resolution, working concentration range, and matrix effects.
• To improve the accuracy of dye concentration predictions in complex tanning matrices.

Main Methods:

• Utilized sequential injection analysis (SIA) coupled with second-order data treatment for dye quantification.
• Investigated the impact of matrix effects on dye analysis in various leather samples.
• Employed the standard addition method to compensate for identified matrix effects and ensure accurate analyte concentration estimation.

Main Results:

• Identified significant matrix effects in at least 80% of the analyzed samples (at a 5% alpha risk).
• Demonstrated the necessity of standard additions for accurate dye concentration determination in the presence of interfering species.
• Successfully applied the developed method to study dye exhaustion during the leather dyeing process.

Conclusions:

• The developed SIA method with second-order data treatment, accounting for matrix effects, provides accurate dye concentration measurements in vegetable-tanned leather.
• Standard additions are crucial for overcoming matrix effects and achieving reliable analytical results in complex tanning systems.
• This approach enhances the understanding and control of dye behavior throughout the leather tanning and dyeing process.