k0-INAA for determining chemical elements in bird feathers

The k0-method instrumental neutron activation analysis (k0-INAA) was employed for determining chemical elements in bird feathers. A collection was obtained taking into account several bird species from wet ecosystems in diverse regions of Brazil. For comparison reason, feathers were actively sampled in a riparian forest from the Marins Stream, Piracicaba, São Paulo State, using mist nets specific for capturing birds. Biological certified reference materials were used for assessing the quality of analytical procedure. Quantification of chemical elements was performed using the k0-INAA Quantu Software. Sixteen chemical elements, including macro and micronutrients, and trace elements, have been quantified in feathers, in which analytical uncertainties varied from 2% to 40% depending on the chemical element mass fraction. Results indicated high mass fractions of Br (max=7.9 mg kg−1), Co (max=0.47 mg kg–1), Cr (max=68 mg kg–1), Hg (max=2.79 mg kg−1), Sb (max=0.20 mg kg−1), Se (max=1.3 mg kg–1) and Zn (max=192 mg kg–1) in bird feathers, probably associated with the degree of pollution of the areas evaluated. In order to corroborate the use of k0-INAA results in biomonitoring studies using avian community, different factor analysis methods were used to check chemical element source apportionment and locality clustering based on feather chemical composition.