Trace element analysis of turkey vulture (Cathartes aura) feathers

Abstract

Ten feather samples, including primary and secondary flight and tail feathers, were analysed for the trace element composition of vane and rachis structures using instrumental neutron activation analysis (INAA), inductively coupled plasma-mass spectrometry (ICP-MS), and cold vapour atomic absorption spectroscopy (CVAAS). Five environmentally significant elements, Cr, As, Se, Sb and Hg, were analysed by INAA and ICP-MS/CVAAS. A further seventeen elements were analysed by ICP-MS. The majority data obtained by INAA and ICP-MS/CVAAS were not statistically significantly different (p = 0.05), although the removal of isobaric interferences using dynamic reaction cell technology was essential to produce ICP-MS data that were consistent with INAA for Cr, As and Se. Significantly higher trace element concentrations were observed for vane relative to rachis for all elements, except Cu and Hg. These elements displayed vane/rachis ratios of 0.7 ± 0.2 and 1.0 ± 0.2, respectively. In general, vane and rachis subgroups afforded data that were consistent with a normal distribution, with RSDs in the range (12–83) % for INAA analyses. A total of 18 outliers were noted amongst the various feather, structure, element combinations, with 14 outliers being observed in the vane and/or rachis structures of the same tail feather. Given the significant differences in vane and rachis concentrations observed for many elements, the large RSDs reported for elements and the potential for outliers, the determination of environmental trace element burden using feathers is significantly enhanced by the analysis of multiple feathers using INAA.