In situ trapping of stibine in externally heated quartz tube atomizers for atomic absorption spectrometry

An evaluation of an extremely simple method for antimony preconcentration based on the novel experimental approach, in situ trapping of stibine in externally heated quartz tube atomizers, is presented. The only difference to the set-up employed for the conventional operation mode is that a flow of oxygen (at stoichiometric excess over hydrogen) is introduced just upstream of the atomizer in the trapping step of the procedure. The volatilization of the trapped analyte can be performed just by switching off the oxygen inlet. The collection/volatilization efficiency (+/- S.D.) is 100 +/- 2%. For the collection time of 300 s (sample volume of 20 ml), the preconcentration ratio and detection limit (3 sigma), respectively, is 400 and 2.8 pg ml(-1). A possible way of further improvement of the detection limit is suggested. The same approach can be analytically useful also for bismuthine (efficiency 55 +/- 2%) but not for arsine, selenium hydride and tellurium hydride. (c) 2005 Elsevier B.V. All rights reserved.