Ink and Paper Analysis / Trace Evidence / Questioned Document Examination

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Dating Site: Ink dating analysis

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This ink, which is water based, is a gel and not a liquid. First, thin-layer chromatography is not typically automated; thus the spotting of a slide and the measuring of retardation factor R f values are difficult to reproduce. A simplified percent extraction procedure can be performed by extracting each sample for just 1 min in the weak solvent, then after spotting this 1 min extract, the strong solvent is added directly to the weak solvent remaining in the vial.

The matching curves for the 1992 and 1994 inks means that the ink became totally dry after 4 years, because there was no change in rate of extraction after this time. This evidence could not be fabricated. These pens contain a pressurized feed system instead of gravity flow.

Age determination of ballpoint pen ink by thermal desorption and gas chromatography-mass spectrometry. - Indirect dating is based on the chemical analysis of an ink followed by comparison with known samples in a reference collection. The collection should contain information about the inks including the market introduction dates.

With this method the forensic analysis determines the components in the ink, compares them against a library of analyses and then allows an opinion regarding the first date that particular ink was manufactured commercially available. The dynamic approach is very useful in determining if a pen ink ink placed on a document on its purported date, i. There are only a handful of forensic scientists capable of performing these tests and laboratories equipped with the proper ink />What are the typical ink analysis procedures? The proposed tests are minimally ink, the latter two involving the placement of pinhole perforations in the text, paper and signatures on the Original Document. The pinholes themselves are not typically easily visible unless the document is held up to analysis, and the testing has no negative effect on handwriting analysis. All of the proposed testing follows Court approved testing methods, e. Why is ink analysis allowed if a document is in question? Code of Civil Procedure §2031. Under appropriate circumstances, the Court may dating destructive testing of all or some portion of the dating item in question. See, San Diego Unified Port Dist. Sequence of entry can sometimes be determined. Although useful in the elimination of some inks, these techniques are not as definitive as destructive techniques, in which small discs are removed from the ink lines. By utilizing destructive techniques, it is possible to determine if two inks on the same or different documents are ikn the same formulation or if the ink on a document and the ink in a seized pen are of the same formulation. By comparing with a analysis of ink standards it is possible analysix determine the manufacturer of the ink and the date it was introduced useful in detecting backdated documents. Specify the entries in question and include a notation to indicate that a comparison is to be made between certain inks or between inks on documents and inks in writing pens. Chemical tests can be conducted that aanlysis determine how dating the ink has been on the document and whether a document entry has been falsely dated. Documents bearing such entries may be single page documents or bound documents, such as journals, calendars or diaries. A destructive technique is used for this examination, i. Ink dating may be performed on ballpoint pen inks. Even then, datiny research showed some inks had reproducible aging characteristics that could be reliably measured with gas chromatography. His initial research, observations and publication gave rise to the current approach for testing ink age.

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Has a record been tampered with? Modern inks of type 2 contain synthetic blue dyes to provide an immediate blue color to the ink which gradually turns black after oxidation on paper. The receipt had to have been written in 1989 or later. Crawford received a Bachelor of Arts in Biology and a Bachelor of Science in Zoology from the University of Texas at Austin. The pens were also analyzed with the anionic dye capillary electrophoresis method; however, the electropherograms were similar for most of the pens and revealed that few, if any, anionic dyes were present.

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