Keywords: Flavoparmelia caperata, biomonitoring, pH titration, epiphytic lichens, acid-base buffering, age, pollution exposure, binding sites
Assessment of acid-base buffering properties of Flavoparmelia caperata: influence of age and pollution exposure
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
adistributions 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.