Category Archives: forensic

Homeland Security, Forensics, Ink, and Thin Layer Chromatography

NewsWise has an interesting article about the U.S. Secret Service using Thin Layer Chromatography to analyze inks – here’s someInkLibrary2 resized 600 excerpts:

Inks in one form or another have been around for at least 5,000 years. Scientists can analyze an ink’s components and determine when it was first manufactured, its brand, its composition, and other information by comparing the analysis results to the more than 10,000 inks and matching analyses stored in the International Ink Library managed by the U.S. Secret Service.

…

To analyze an ink sample, forensic scientists separate its components using planar thin layer chromatography. This process uses solvents to separate the ink into bands of color on a page. Each ink creates its own color bands, thus forming a “fingerprint.” Scientists compare the unknown sample’s bands to known samples to find a match.

You can read the complete article by clicking here.

And here’s that great clip from CSI showing ink analysis with Thin Layer Chromatography:

LCGC’s “The Column” Cover Story: Unlocking the doors with TLC

The new issue of LCGC’s “The Column” features a great The columncover story on Thin Layer Chromatography. The article, written by Analtech Technical Director Ned Dugan, explores the many ways TLC is being used.

The article focuses on some key examples:

  • Fighting the Scourge of Counterfeit Medications
  • Protecting Infants from Patulin Contamination
  • Identifying a new nucleotide in human DNA
  • Identifying the H1N1 Virus
  • Use in Forensic Science

Click Here to see the entire issue.

VIDEO REPORT: Chromatography used to identify 300 Year-Old Native American Dyes

WHYY Senior Health and Science Reporter Kerry Grens’ report on research by University of Delaware Doctoral Student Christina Cole on the composition of dyes used by Native Americans using chromatography. The report features an explanation of chromatography by Analtech General Manager Steven Miles and an interview with Delaware State University Prof. Claytrice Watson about forensic science.

Thin Layer Chromatography advocated in Forensic Magazine

Oliver Grundmann, Ph.D. and Ian Tebbett, Ph.D.   have published a piece in the February/March issue of Forensic Magazine in which they advocate the use of Thin Layer Chromatography. Here’s an excerpt:

Forensic Magazine“Other methods for the detection of mycotoxins include rapid screening by thin layer chromatography (TLC) as well as radio immunoassay (RIA) or enzyme-linked immunosorbent assays (ELISA) in serum, urine, gastric, and stool samples. A recently introduced ELISA for amanitine has been evaluated for its use in determining Amanita phalloides poisonings in urine, serum, and fecal samples. The ELISA-based approach yielded sufficient sensitivity and specificity compared to LC/MS and RIA methods in urine samples if analysis occurred within the first 36 hours after ingestion. Since ELISA kits do not require complex extraction procedures or the use of radioactivity, this might provide a time- and cost-effective alternative.

As low-tech as TLC might appear to be, it has been frequently used for qualitative identification of a variety of mycotoxins in biological fluids. Orellanine, a toxin from the mushroom Cortinarius orellanus or Fool’s webcap, has been identified by TLC in serum and urine after photodecomposition to orelline.”