Determination of hydride -forming elements by atomic spectrometry
The parameters affecting the generation of stibine (SbH3) from homogeneous borohydride solutions and immobilized borohydride were evaluated for a flow injection system coupled to a quartz tube atomic absorption spectrometer. The stibine release and transport efficiency were affected by the design of the hydride generator and the vapor generation conditions.
A new method for the determination of antimony by quartz tube atomic absorption spectrometry with flow injection chemical vapor generation from a tetrahydroborate-form anion exchanger was developed. Flow injection hydride generation parameters were optimized. Several samples could be injected before the column was reloaded with borohydride. Interferences from transition and hydride forming elements and signal suppression due to high ionic strengths were eliminated. The developed method was successfully applied for the determination of antimony in spiked natural waters.
Several synthetic organic cation exchangers, inorganic ion exchangers and organic sorbent ion exchangers were evaluated as selective sorbents for inorganic antimony preconcentration without prior complexation. Neither the organic cation exchangers, nor the organic sorbent ion exchangers gave good results. Only one of the inorganic ion exchangers evaluated gave satisfactory results.
The different parameters affecting the generation of arsine, bismuthine and hydrogen selenide from immobilized borohydride were evaluated by using a flow injection system coupled with a quartz tube atomic absorption spectrometer. Hydrides from these elements were generated from immobilized borohydride in the presence of other hydride-forming elements. In all cases, multiple injections were made before the column needed to be reloaded with borohydride.
A new method for the simultaneous determination of antimony, arsenic, bismuth, selenium, tin and mercury by flow injection chemical vapor generation atomic emission spectrometry with tetrahydroborate immobilized on a strong anion exchange resin was developed for the first time. Both flow injection and vapor generation parameters were optimized. Simultaneous vapor generation, good sensitivities and low detection limits were achieved. The developed method was successfully applied to the determination of antimony, arsenic, bismuth, selenium, tin and mercury in natural water samples and a standard reference material with satisfactory results. Preliminary results for chemical vapor generation of manganese, zinc, nickel, cobalt, iron and lead were obtained.