Mussel samples (30 mg) were directly weighed
into the glass minicolumn. The minicolumn was
then connected to the CUES. The continuous
copper determination system is shown in Fig. 1.
First, the CUES circuit (1.3 ml) was loaded with
the acid leaching solution (3 M hydrochloric acid
and 3 M nitric acid). Once the CUES circuit was
closed, the leaching solution was circulated at 3.5
ml miny1 through the minicolumn for 5 min under
ultrasonic treatment, changing the direction of the
flow each 30 s in order to avoid sample accumulation
at the minicolumn ends. The switching valve
(SV) was then changed to its other position and
the acid extract was homogenized on the mixing
coil. A volume of 250 ml of acid extract was
injected by means of the injection valve (IV) into
an ultrapure water carrier stream and the copper
signal was continuously monitored by FAAS. Aliquots
of 250 ml of standard solutions containing
between 0 and 5 mg mly1 of copper, in the same