flow injection pre-concentration system with a chelating
resin was developed to determine trace and ultratrace
amounts of cadmium in mussels by flame atomic
absorption spectrometry. The metal was preconcentrated
on a minicolumn packed with poly(aminophosphonic acid)
resin and eluted with dilute hydrochloric acid into the
nebuliser–burner system of an atomic absorption
spectrometer. A preconcentration factor of 16–47,
equivalent to 3.4–10 ml of sample, was achieved by using
a time-based technique. The detection limit (3s) in the
sample digest was 0.56 mg l21 for a sample volume of 3.4
ml. The precision (relative standard deviation) obtained
for different amounts of cadmium was in the range
1.4–6.6% at the 1–20 mg l21 level. Chemical and flow
variables, and other figures of merit of the proposed
methodology, were studied. The method demonstrates
high tolerance to interferences, and the analytical results
obtained for a certified reference material were in good
agreement with the certified value. The method was
successfully applied to the determination of trace amounts
of cadmium in mussel samples from estuaries in Galicia