Fluorimetric determination of beryllium with 3-hydroxy-2-naphthoic acid by flow injection analysis after preconcentration on a silica gel microcolumn

A method was worked out for the selective determination of trace concentrations of beryllium by flow injection analysis (FIA) with fluorimetric detection using 3-hydroxy-2-naphthoic acid (λex = 375 nm, λem = 455 nm) at cL = 50 μmol l-1 in 0.1M ammonium acetate, pH 7·1. In injected sample volumes of 80 μl, Be can be determined in concentrations of 10 to 156 μg l-1 with relative standard deviations not exceeding 5%, after its selective sorption on a microcolumn (2 x 40 or 3 x 30 mm) of silica gel from a medium of 0.05M-EDTA and 0.1M tartaric acid followed by elution with 0.1M-HCl. After preconcentration from 5 to 15 ml volumes, Be can be determined under the same conditions in samples at concentrations of ρBe = 0.5 to 4.6 or 0.1 to 0.8 μg l-1, respectively, with sr from 6 to 12%, the enrichment factor being as high as 200. The method was applied to beryllium bronzes and to dust from the atmosphere of the beryllium bronze foundry. The relative deviations of the beryllium content did not exceed 8% for the bronzes as compared to certified values, and 5% for the dust as compared to results obtained by ETA AAS.