Spectrophotometric determination of trace amounts of beryllium using 1,8-dihydroxyanthrone as a new chromogenic reagent

Abstract

A simple, rapid, and sensitive spectrophotometric method for the trace level determination of beryllium based on the formation of a 1:2 complex with anthralin (1,8-dihydroxyanthrone) as a new reagent is developed. A spectrophotometric method was used to determine the acidity constant and stepwise proton dissociation of the reagent. The experimental conditions for determining beryllium including the influences of pH, reagent concentration and time were evaluated and optimized. Under the optimum experimental conditions, the molar absorptivity of the complex is 0.47 × 10⁴ l mol⁻¹ cm⁻¹ at 545 nm. Calibration graph was linear in the range of 0.04–1.04 μg ml⁻¹ with a detection limit of 0.012 μg ml⁻¹ and a %RSD of 0.43%, for 5 replicate determinations at 0.48 μg ml⁻¹ of Be(II). The interferring effect of some cations and anions was also studied. The method was applied for the determination of beryllium in beryl, silicate rock and alloys. Ethylenediaminetetraacetic acid (EDTA) was used for masking interfering ions.