Phenoxyethanol Decay
Definition
Loss of phenoxyethanol solvent from a ballpoint stroke over weeks to months, measurable by GC-MS or GC-FID. The basis of the Aginsky 1996 solvent-extraction age-dating method.
- Process
- Loss of phenoxyethanol solvent from a ballpoint stroke
- Timescale
- Weeks to months
- Measurement
- GC-MS or GC-FID
- Origin
- Aginsky 1996 solvent-extraction age-dating method
Common questions
What is the Aginsky method actually measuring?+
It extracts residual phenoxyethanol from a small punch of the ink stroke and compares the extracted quantity against reference decay curves to estimate how much time has passed since the ink was applied.
Why can two documents from the same pen and date give different decay readings?+
Decay rate is sensitive to storage conditions such as heat, light, and humidity, and to how much ink was deposited, so identical writing instruments used on the same day can still show diverging phenoxyethanol levels later.
Is phenoxyethanol decay used to date a document in isolation?+
It is normally combined with other lines of evidence, such as paper composition or other ink components, because solvent decay alone is vulnerable to storage-condition variability that can skew the age estimate.
Related terms
- Aginsky Method
- Solvent-extraction ink-age dating (Valery Aginsky, 1996). Compares fast and slow solvent extractions of phenoxyethanol to derive an aging parameter for ink under...
- ASTM E2789-11
- ASTM standard guide for forensic examination of inks (ink-age dating context). Pairs with ASTM E1422 for paper examination by FTIR.
- Ballpoint Ink
- An oil-based, high-viscosity ink using a resin binder (alkyd or polyamide) in a high-boiling solvent (phenoxyethanol or benzyl alcohol), with triphenylmethane dyes...
- Brunelle R-Ratio Method
- Dye-degradation method (Richard Brunelle and Kenneth Pro, 1972, later refined). Tracks the ratio of extracted and unextracted dye over time to estimate...
- Dye-Based Ink
- Soluble colourant dissolved in solvent. Modern fountain-pen and dye-based ballpoint inks belong here. TLC separates the dye mixture into resolvable spots.
- Gel Pen Ink
- Water-based gel vehicle with pigment particles (often copper phthalocyanine, iron oxide). Behaves like a pigment ink on TLC but more porous on...
- Iron-Gall Ink
- A historical ink formulation of ferrous sulphate, tannic acid (from oak galls), and gum arabic. The ferrous-tannate complex oxidises to brown ferric-tannate...
- LDI-MS / MALDI-TOF
- Laser-desorption mass spectrometry. Reads dye molecular ions directly from the ink stroke with minimal sampling, increasingly used for ink-library searching.
- Optical Brightener
- Stilbene-based fluorescent whitening agent added to paper from the early 1950s onwards; under 365 nm UV the paper glows bluish white. A...
- Pigment Ink
- Insoluble colourant (carbon black, titanium dioxide, organic pigments) suspended in a binder. Pigment particles do not migrate on TLC, so Raman, FTIR...
- Raman Spectroscopy
- A non-destructive laser-based technique sensitive to molecular vibration modes in pigments; complements FTIR by characterising pigment molecular structure rather than bulk ink...
- TLC and HPTLC
- Thin-layer and high-performance thin-layer chromatography. Silica gel plates eluted with ethyl acetate / ethanol / water or methanol / ethanol mixes; Rf...