Determination of trace amounts of beryllium(II) in drinking water and of beryllium vapor in air by graphite-furnace atomic absorption spectrophotometry using acetylacetone as a chelating agent

A chelate of beryllium acetylacetonate, Be(acac)(2), was formed from beryll ium(II) (1.0 - 40.0 ng) in drinking water(100 mi) containing acetylacetone (0.2%(v/v), 7.0 - 14.0 ml) in ammonium acetate buffer (14-28 mmol) together with a slightly acidic solution (0.2%(v/v) of HCl, 3.0 ml) at pH 5.5. The Be(acac)(2) chelate was preconcentrated on a Sep-Pak Cls cartridge and was eluted with methanol (2.00 ml). A portion (20 mu l) was introduced into a g raphite cuvette and was atomized according to a temperature program. The me thod detection limit (3 sigma) for beryllium(II) was 2.3 ng/l; the calibrat ion graph was linear up to 400 ng/l. Accuracies of 97.0 - 101% were obtaine d when testing a quality control (QC) water sample (HPS #290608) and a synt hetic natural water standard (Standard Reference Material 1643d) with a rel ative standard deviation (n=4) within 2.3%. The proposed method could be ap plied to the measurement of beryllium vapor in air with a detection limit o f 0.23 ng.