Forensic laboratory results limitations

Limitations on the Interpretation of Forensic Laboratory Results (Mr. C. R. Mldklff)... 

Mr. Mldklff introduces this topic In the following manner Recently, increasing concerns have been addressed about the reliability of results from forensic laboratories. One question of particular concern which may be asked is the extent to which these poor results are attributable to attempts to push detection limits beyond the limits of reasonable scientific certainty, making interpretation of results tenuous. 

By contrast. In Che forensic laboratory, Che quantity of sample Is often limited and additional material Is unobtainable. As a result, there Is little opportunity for analytical methodology modification and matrix adjustment or optimization. Further, Che matrix Itself Is variable as In cases Involving arson. 

Atomic absorption remains a staple of forensic chemistry, given its low cost, simple operation, and easy maintenance. The limitations are related to versatility. Unless multielement lamps are used, only one element can be tested for at a time, and each element requires a separate lamp and instrument optimization. For small target lists such as a list of barium, antimony, and lead for GSR, this is not onerous, but still is inconvenient. Limits of detection are in the low-ppm to high-ppb range for most elements, As a result, a few forensic laboratories have turned to inductively coupled plasma atomic emission spectroscopy (ICP-AES) for additional elemental analysis capability. 

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