Iron-based inks can be dated by measuring the migration of iron along the fibers of the paper by Scanning auger microscopy.This article describes state of the art procedures for the chemical and physical comparison, identification and dating of inks on questioned documents.It can, however, be done if desired, but has no bearing on the results.Chemical and physical analysis of inks on questioned documents provides valuable information regarding their authenticity.Caution should be taken to not get any combination from such things as other inks, inks from the opposite side of the document, or printed stamps. This will normalize all the values and make them mass independent.
Six experiments were conducted using the following procedures. Samples of the known and questioned ink are removed from the paper using a hollow needle punch with a plunger to push the sample out of the needle. Inject 20-30 microliters of a weak solvent like n-butanol, into the vial and make sure all the plugs are covered. 4 microliter aliquots are then taken using a volumetric pipette after stirring by rotating the vial five times before such aliquots are taken and spotted on a Merck HPTLC plate. After the desired aliquots have been taken at the desired times, usually 30 seconds, 90 seconds, 3 minutes and 10 minutes, 10 microliters of Benzyl Alcohol, or another strong solvent is then added and allowed to extract for 5 minutes. Another 4 microliters aliquot is taken of this solution and spotted on the TCL plate as well. The relative intensities of all 5 spots are calculated using a Densitometer and then using the following formulas: R-Ratios Percent Extraction 10 minute extraction value Benzyl Alcohol value Percent extraction can also be calculated at 30, 90, and 120 second times to obtain a percent extraction curve.
The UPV/EHU's research team --comprising the professor of Analytical Chemistry Rosa María Alonso, Dr Itxaso San Román of the Farmartem group of the Department of Analytical Chemistry, and Dr Luis Bartolomé of the Central Analysis Service of Bizkaia (SGIker)-- has developed the Datink method that allows the period of time the ink may have remained on the paper to be determined and its age to be ascertained.
But this technique is also able to overcome other stumbling blocks relating to the amount of ink deposited when writing and the type of paper used, as these variables hamper the dating of a document by means of traditional methods.
Ink dating is a highly specialized forensic examination and considered to be one of the most accurate and reliable methods to help determine the age of a document. has extensive experience as a forensic chemist and document dating specialist.
An ink formulation can be identified to a specific manufacturer to ascertain the first date of commercial availability. He trained with and served as the Chief Research Forensic Chemist with the United States Secret Service and was responsible for maintaining the largest known forensic collection of writing inks in the world.
Dating tags are unique chemicals that have been added to ball-point inks by some ink companies as a way to determine the year the ink was made.