Results for ILC 5

In the fifth, FIRMS Network Inter-Laboratory Comparison of stable isotope measurements three test materials were distributed to 40 laboratories worldwide. The materials distributed were cellulose, ammonium nitrate and mammalian bone. Laboratories were requested to perform 10 measurements for each element (δ2H, δ13C, δ15N, δ18O) of each analyte. A method for the isolation of collagen from the bone was supplied. Laboratories were also invited to analyse the bone sample for lead and strontium isotopic composition.

Overall, 29 laboratories submitted results. Not every laboratory submitted ten replicate results and some only reported results for a selection of samples. A limited number of laboratories return results for lead or strontium isotopic composition and these data are not presented here.

Results for this study have been circulated to participating laboratories. Results for previous ILCs have been published in a special edition of the Forensic Science Society’s Journal, Science and Justice (doi:10.1016/j.scijus.2008.12.002).
ILC Year Materials Elements
1 2002 cane sugar & flour δ13C, δ15N
2 2004 phenacetin & polyethylene film δ13C, δ15N, δ2H
3 2006 horse hair & paper x2 δ13C, δ15N, δ2H, δ18O
4 2008 benzocaine & poly(ethylene glycol) δ13C, δ15N, δ2H, δ18O
5 2009 ammonium nitrate, cellulose and bone δ13C, δ15N, δ2H, δ18O, Pb Sr

Table 1: ILCs to date

Figure 1: ILC participants by element
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