DETERMINATION OF ARSENIC BY INDUCTIVELY-COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY ENHANCED BY HYDRIDE GENERATION FROM ORGANIZED MEDIA

A method is described for the determination of arsenic, which combines a continuous flow hydride generation technique with an inductively coupled plasma atomic emission detection system. Some atomic absorption preliminary studies are described as well. Arsine is generated with NaBH4 from a didodecyldimethylammonium bromide (DDBA) vesicular medium. The analytical performance of this vesicles-enhanced method is superior to the generation of the hydride from aqueous media: the detection limit (0.6 ppb) is improved by a factor of 2 and greater tolerance to interferences is observed for arsine generation from DDBA vesicles. Precision of As determinations is also improved. The proposed method has been validated for low As levels determinations in two Certified Reference Materials (CRM) sediments with satisfactory results. The potential of organized media to improve hydride generation is addressed.