A comparative study of ballpoint ink ageing parameters using GC/MS.

Area of Science:

• Forensic Science
• Analytical Chemistry
• Material Science

Background:

• Developing reliable methods for dating ink has been a long-standing challenge.
• Existing methods for ink ageing lack consistent reliability and raise scientific concerns.
• Ink drying complexity makes identifying a reproducible ageing parameter difficult.

Purpose of the Study:

• To evaluate four ageing parameters for reliably tracking ink ageing over time.
• To assess the influence of ink composition, writing pressure, and storage on ageing parameters.
• To determine the most suitable parameter for ink dating applications.

Main Methods:

• Monitoring phenoxyethanol (PE) loss in ink lines.
• Calculating relative peak area (RPA) by normalizing PE with stable volatile compounds.
• Determining solvent loss ratio (R%) and a modified version (R%*) from PE and RPA data.
• Evaluating parameter repeatability and the impact of various factors on results.

Main Results:

• The standard solvent loss ratio (R%) exhibited the highest standard deviation, indicating lower reliability.
• Relative peak area (RPA) demonstrated greater consistency and potential for reliable ink ageing assessment.
• The study identified limitations of current analytical methods and factors influencing ageing parameter accuracy.

Conclusions:

• The solvent loss ratio (R%) is not the most reliable parameter for ink dating.
• Relative peak area (RPA) shows promise as a more adequate parameter for monitoring ink ageing.
• Further research and systematic experiments are needed to refine ink dating methodologies.