The degradation behaviour of methylmercury (MeHg) under microwave irradiation is investigated,
as is the (different) degradation behaviour of ethylmercury (EtHg) under similar irradiation.
A simple and highly sensitive SPME-GC-pyrolysis-AFS system was used to analyse the
aqueous MeHg and EtHg standard solutions after derivatization with sodium tetraphenylborate
(NaBPh4). Samples were irradiated in a microwave digester at microwave powers ranging
from 20 to 160 W for durations of 2 to 10 min. The different tolerances towards microwave
treatment of the two organomercury species were evident. Practically no degradation
was experienced for MeHg for up to 8 minutes of irradiation at 120 W or for up to
4 minutes at 160 W. Significant analyte loss was observed for EtHg after 2 minutes
at 40 W of microwave power.