Determination of trace antimony(III) with pyrocatechol violet in water by graphite-furnace AAS after preconcentration on a membrane filter with a finely pulverized anion-exchange resin

A sensitive method based on preconcentraion on a membrane filter with an an ion-exchange resin suspension (ARS) has been developed fur the determinatio n of Sb(III) in water samples by graphite furnace atomic absorption spectro metry (GF-AAS). Sb(III) (0.02 similar to 0.2) mug, in 20 similar to 500 mi of a sample solution, was retained as a Pyrocatechol Violet (PV) complex an ion on a resin at pH 7; the resulting resin was filtered through a membrane filter. A portion of the resin with the membrane filter (3 mm in diameter) was inserted into a cuvette, and the absorbance of Sb was measured at 217. 6 nm. The relative standard deviation for five measurements at 0.1 mug of S b(III) was 5%. The detection limit was 5.4 ng of Sb(III) in 500 ml {10.8 ng Sb (III) l(-1)} of the water samples. EDTA was used as a masking agent to r emove any interference of Sr(II), Fe(II), Fe(III), Pd(II), Cu(II), AI(III) and Ga(III). The proposed method has been applied to the determination of S b(III) in river water.