Determination of Ultratrace Beryllium in Natural Water by Electrothermal Atomic Absorption Spectrometry after Preconcentration with One-Drop Solvent

摘要

An effective method for the determination of beryllium at sub ng dm~(-3) levels in natural water is described. Beryllium is extracted with acetylacetone into chloroform. The organic phase is transferred to a Teflon beaker containing a micro volume of dimethyl sulfoxide (DMSO, a high boiling-point solvent); chloroform is then removed by evaporation in a water bath (ca. 35 deg C). Beryllium is concentrated in the residual DMSO and determined by electrothermal atomic absorption spectrometry. The sensitivity and stability of beryllium atomic absorption were enhanced in the presence of palladium as a matrix modifier. The detection limit (3#sigma#) for beryllium was 0;050 ng dm~(-3), based on a 400-fold preconcentration using 40 cm~3 of the sample water; the relative standard deviation was 1.8% (2.0 ng dm~(-3), n=8). The concentration of dissolved beryllium in natural water was found to be 0.25-0.63 nag dm~(-3) by the proposed method.