Electrochhemical hydride generation and tungsten trap atomic absorption spectrometry for determination of antimony

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2008
Yıldıran, Ahmet
Electrochemical hydride generation is an alternative technique to the chemical hydride generation by NaBH4 which is widely used for atomic spectrometric determination of volatile elements such as As, Bi, Ge, Pb, Sb, Se, Sn and Te. The aim of this research has been to develop an analytical technique at the level of ng/L for determination of antimony by using a simple and inexpensive AA spectrometer and the other parts that can be built in any laboratory. Carbon rod and platinum foil were used as cathode and anode materials, respectively, for the generation of antimony hydride. Argon was used as the carrier gas. Zr coated W-coil was used for on-line preconcentration of generated hydrides. A new apparatus independent from quartz T-tube atomizer was constructed and used to contain the atom trap. Zr coated W-trap was heated to the collection temperature for trapping the analyte species generated electrochemically. For the revolatilization of the trapped species, the trap was further heated to the revolatilization temperature. Revolatilized species were transported to a flame-heated quartz tube atomizer where the analytical signal was recorded. Duringcollection and revolatilization steps hydrogen gas was introduced into the system to prevent the oxidation of atom trap. The experimental operation conditions for electrochemical hydride generation and atom trapping were optimized. 3σ limit of detections were found to be 0.012 ng/mL and 0.41 ng/mL with and without using trap, respectively. The trap has provided 34 fold sensitivity improvement as compared with the electrochemical hydride generation alone. The interferences of some hydride forming elements and some transition metals on electrochemical hydride generation with and without employing the trap were investigated. Analysis of standard reference material was performed to check the accuracy of the proposed method.

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Citation Formats
A. Yıldıran, “Electrochhemical hydride generation and tungsten trap atomic absorption spectrometry for determination of antimony,” M.S. - Master of Science, Middle East Technical University, 2008.