Direct determination of silver at parts-per-billion level in waters by derivative atomic absorption spectrometry using the atom trapping technique

Abstract

A method has been developed for the direct determination of trace silver using derivative atom trapping flame atomic absorption spectrometry with modified water-cooled stainless steel trapping equipment. The conditions that influence the sensitivity of the method were studied. For a 1 min collection, the characteristic concentration (giving a derivative absorbance of 0.0044) and detection limit (3σ) were 0.18 ng ml −1 and 0.29 ng ml −1, respectively, 383 and 66-fold better than those of the conventional flame atomic absorption spectrometry. The detection limit and characteristic concentrations of the proposed method for a 3 min collection time were 2 and 3 orders of magnitude higher than those of conventional flame atomic absorption spectrometry. The present method was applied to the determination of silver in water samples with a recovery range of 91–109% and a relative standard deviation of 5.0–5.8%.