Solvent-Loss Dating
Definition
An ink dating approach based on measuring the concentration of residual semi-volatile solvents (particularly phenoxyethanol in ballpoint ink) relative to a non-volatile reference; the ratio decreases with age as solvent evaporates or migrates, enabling estimation of minimum ink age.
- Target compound
- Phenoxyethanol, a semi-volatile solvent in ballpoint ink
- Basis
- Ratio of residual solvent to a non-volatile reference declines over time
- Output
- Estimate of minimum ink age
- Field
- Forensic ink and questioned document dating
Common questions
Why does the method give only a minimum age estimate rather than an exact date?+
Solvent loss rate depends on storage conditions such as temperature, humidity and how the document was kept, so without knowing that history the measured ratio can only bound how much time has passed since writing, not fix a precise date.
What can accelerate or slow solvent loss enough to mislead the dating result?+
Heat, sunlight exposure, lamination and certain storage environments can drive off solvent faster than natural ageing, while cool sealed storage slows it, so examiners must consider a document's known handling history before interpreting the result.
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