Title: Assessment of acid-base buffering properties of Flavoparmelia caperata: influence of age and pollution exposure

Authors: R.M. Godinho, Tona G. Verburg, Maria do Carmo Freitas, Hubert T. Wolterbeek

Addresses: Unit of Reactors and Nuclear Safety, Neutron Activation in Environment, Epidemiology and Nutrition, Instituto Tecnologico e Nuclear, Apartado 21, E.N.10, 2686-953 Sacavem, Portugal. ' Department of Radiation, Radionuclides & Reactors, Section RIH (Radiation and Isotopes in Health), Faculty of Applied Sciences, Technical University Delft, Mekelweg 15, 2629 JB Delft, The Netherlands. ' Unit of Reactors and Nuclear Safety, Neutron Activation in Environment, Epidemiology and Nutrition, Instituto Tecnologico e Nuclear, Apartado 21, E.N.10, 2686-953 Sacavem, Portugal. ' Department of Radiation, Radionuclides & Reactors, Section RIH (Radiation and Isotopes in Health), Faculty of Applied Sciences, Technical University Delft, Mekelweg 15, 2629 JB Delft, The Netherlands

Abstract: This paper focuses on binding sites of lichens. The aim was to investigate the extracellular ionisable functional groups or binding sites that can play a (binding) ligand|s role in young (peripheral) and older (central) thallus parts of the epiphytic lichens Flavoparmelia caperata collected under different pollution load environments. Potentiometric acid-base titration was used to obtain the capacity of lichens to retain extracellularly bound H+ and pKa distributions describing the acid-base properties of the lichen. Titration data were used to constrain the proton-exchange properties of surface functional groups. The results indicate that for F. caperata, neither ambient conditions nor specific lichen thallus parts affect capacity and pK values of ionisable groups.

Keywords: Flavoparmelia caperata; biomonitoring; pH titration; epiphytic lichens; acid-base buffering; age; pollution exposure; binding sites.

DOI: 10.1504/IJENVH.2011.039853

International Journal of Environment and Health, 2011 Vol.5 No.1/2, pp.19 - 31

Published online: 22 Apr 2011 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article