Leucoquinizarin as an analytical spectrophotometric and fluorimetric reagent. Part 2. Determination of beryllium

Abstract

The reaction between beryllium and leucoquinizarin was studied both spectrophotometrically and spectrofluorimetrically, and methods for the determination of beryllium are proposed on the basis of the 1 : 1 chelate formed. The yellow chelate is formed at pH 5.3–5.5 in a medium containing 20% of ethanol, and the absorption is measured at 438 nm. The molar absorptivity (1.2 × 10⁴ l mol^–1 cm^–1) allows the determination of 0.1–0.8 p.p.m. of beryllium. The fluorimetric method allows the determination of 5–100 p.p.b. of Be²⁺ in a medium containing acetate buffer (pH 4.6) and 70% of ethanol (λ_exc= 450 nm, λ_em= 476 nm). The fluorimetric method has been applied to the determination of beryllium in an aluminium alloy.