filtration of the sample solution. With this procedure,
testing sensitivity was enhanced.
In this work, the dithizone membrane was
prepared using a cellulose ester membrane coated
by dithizone nanofibers. This dithizone membrane
was simply applied to the selective enrichment of
Hg(II) ions by the filtration of sample solution method.
Then, the development of orange-brown color will
take place due to the reaction between Hg(II) ions
and dithizone membrane. The color intensity
depends on the amount of Hg(II) ions extracted on
the membrane. The effects of a sample volume and
the flow rate of filtration on Hg(II)-extraction were
then studied. The detection limit and repeatability were
also evaluated. Moreover, the stability of dithizone
membranes was improved against oxidation from
air and/or light by adding ascorbic acid as a reducing
agent and keeping dithizone membrane in an aluminum
bag with oxygen absorber under vacuum. Finally,
the presented technique was applied to determine the
concentration of Hg(II) ions in the samples collected
from various sites such as waste, river and sea.