Abstract：A flow injection on-line micro-column preconcentration system with anionexchange-
resin being used as sorbent was developed for flame atomic absorption spectrometric
(FAAS) determination of trace cadmium. Cadmium ion was on-line reacted with the chelating
reagent of 8-hydroxylquinoline-5-sulphonic acid(OXS) in the condition of pH 7.2 to form a
complex anion,which was then retained on a micro-column packed with D-290 anion-exchangeresin.
The retained cadmium species was eluted with a nitric acid solution of 1 mol.L-1,and the
elutant was directly transported into the nebulizer of the FAAS. Under the optimized conditions,
an enrichment factor of 10 was achieved for a loading period of 120 seconds,and a detection limit
of 0.5 μg.L-1 and a relative standard deviation of 1.0% for eleven determinations of 0.1 mg.L-1
cadmium standard solution were obtained at the sampling frequency of 24 h-1. The proposed
method has been applied to determine the trace amount of cadmium in fresh water samples.
