James 10/7/08
Current Event – Forensics
New ink sampling technique taking a bite of out time
July 18, 2007
Ames, Iowa –
In this article researchers at the Midwest Forensics Resource Center at Iowa State University are building a library of ink profiles to help forensic scientists identify inks on fraudulent documents and other evidence. In this process scientists will pair mass spectrometry with new sampling technique called “Direct Analysis with real time (DART). This process will reveal the chemical make up of ink faster. This will show a greater detail than we have seen before.
The process goes like this DART mass spectrometry analyzes ink by creating a stream of warm gas containing excited-state helium atoms or nitrogen molecules in the DART source. The gas stream is pointed at an ink sample, and the gas and excited-state species evaporate and ionize the molecules from the sample. A mass spectrometer measures the production of ions to create mass spectrum data from each ink sample tested. Unlike other ink analysis liquid chromatography only requires a small sample from the document and does not alter them physically or visually. The great thing about the DART system is that it can take a sample of the ink straight off the paper. You don’t have to extract the sample first. Before this process we had to cut a little bit of sample out and dissolve it in solvent for analysis. In essence we don’t destroy the evidence. The great thing about this if we don’t alter or destroy the evidence, it will hold up in court in order to indict the criminal every time. Also, with this process we can analysis more cases in a shorter period of time. Prior to DART scientists could not even do the ink sample tests because of the caseloads were so large.
Jones and John McClelland, Ames Laboratory senior physicist and DART project leader plan a three phase project. The first phase is to create and determine the best way to make inks and build the library. The second phase was ink mass spectra to produce. The third phase is make a project to focus on creating a computer software, always used to store and access the mass spectra library.
2 comments:
Three aspects of this review that were very well presented were what happened, where it happened, and how the process works. Two suggestions on how to improve the review are to explain the DART system in a simpler manner, using more common wordings, and to provide the time when the DART system was invented. One thing that impressed me about your review was that the DART system can take a sample of the ink without disrupting the document. Overall, great job.
Sincerely,
Boromir
Three positive aspects of the review was that it was an interesting topic, well written, and thoroughly explained. Two suggestions to improve this review is to state when this ink process will be completed and how long the DART technique takes. I was impressed that, by using this process, criminals will be convicted each and every time.
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