In a biomonitoring study aiming to find alternatives to lower epiphytes as air-quality monitors, lichens and tree bark were
exposed at different sites for discontinuous periods of 2 months and continuously. Native lichens were collected as well.
The contents for 22 elements were obtained by both instrumental neutron activation analysis (INAA) and inductively coupled
plasma mass spectrometry (ICP-MS). Quality control as asserted by analyzing ISE-921, NIST-1547 and TL-1 was good Losses of
As and Se by volatilization during sample digestion and neutron irradiation were evident, Ca contents by ICP-MS appeared underestimated
probably due to the formation of the insoluble fluoride. ICP-MS featured a better precision than INAA. Nonparametric statistics
were applied to the ICP-MS replicates, to those determined by INAA, and to compare the results of both techniques. High or
even excellent correlations were found between replicates in INAA, whereas, in ICP-MS, Cr and Ta were just fairly or not correlated.
As an overall comparison of the techniques, biased results were found for As, Ba, Ce, Cr, Cs, Hf, La, Sc, Se, Ta, and Zn,
unbiased results could be found for Ca, Co, Fe, K, Na, Rb, Sb, Sm, Tb, Th, and U.