Evidence polymer, forensic analysis

Keratin is a natural single-strand polymer consisting of chains of amino acids, with a high proportion of the two sulfur-containing amino acids cysteine and methionine. Keratin is the polymer of hair and nails. The sulfur atoms account for keratin s ability to bond to arsenic, mercury, and lead. Hair analysis has played an important role in forensic evidence in cases of poisoning, and it has been possible to diagnose the extent to which famous people in history were affected by these toxic elements provided a sample of their hair has been preserved. 

Re-examines methods in areas with a long history of analysis by pyrolysis including microorganisms, coatings and adhesives, textiles, synthetic polymers, cosmetics, and forensic evidence... 

Fibers—specifically, textile fibers—are common forms of transfer and trace evidence and are arguably the largest category of polymer evidence anal) zed in forensic laboratories. Fibers are amenable to analysis with nearly ev ery kx)l available to the forensic chemist, from optical instruments and PLM to microspectrophotometry and chromatography. As the arsenal of anal)dical tools available grows, fiber evidence is getting renewed interest from forensic chemists and hace evidence analysts. 

The combination of pyrolysis and GC (PGC) is a powerful and sensitive method for discriminating certain types of physical evidence. PGC has been applied to a wide variety of sample types, but by far the major application of PGC has been in polymer analysis. In the crime laboratory, PGC provides one of the most discriminating tests for forensic paint comparisons. 

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