Tubular electrolytic hydride generator for continuous and flow injection sample introduction in atomic absorption spectrometry

An electrolytic hydride generation system for sample introduction in atomic spectrometry is described. The system uses a tubular electrolytic flow-through cell with a concentric arrangement and a packed cathode made of vitreous carbon. The large cathode surface area (about 120 cm(2)) gives efficiencies in hydride production of > 90% for As(III), Se(IV) and Sb(III). Samples can be introduced in both continuous and flow injection modes, because the low dead volume (390 mu l) of the generator complies with the dispersion requirements of flow injection systems. The generator was coupled to a flame heated quartz tube for atomic absorption measurements. The detection limits for As, Se and Sb in aqueous solutions were 5.2, 2.5 and 1.4 ng ml(-1), respectively, with relative standard deviations of 0.7-3.3%.