Analytical Sciences

Pyrolytic and Non-Pyrolytic Boron Nitride Platforms in Electrothermal AAS for the Determination of Cadmium in Sea and Estuarine Water without Chemical Modification

Shoji IMAI,* Yukari KANEMATSU,* Azusa SATOH,* and Akira YONETANI**

*Department of Chemistry, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan
**Hitachi Sciencesystems Co. Ltd., Hitachinaka, Ibaraki 312-8504, Japan

The analytical performance of pyrolytic and non-pyrolytic boron nitride (PBN and NBN) platforms, attached to a commercially available graphite tube furnace, in electrothermal atomic absorption spectrometry (ETAAS) for Cd was studied. Although the tolerable pyrolysis temperature was 300°C with the conventional pyrolytic graphite platform, it increased to 600 and 950°C with the PBN and NBN platforms, respectively. The lifetime of the ceramic platform was 500 firings. The NBN platform provided an enhanced sensitivity with a better reproducibility than others. Using the NBN platform allowed the LOD, based on the variability of the blank (3 σ), to be 0.1 µg l^-1 within a seawater matrix (20000 mg NaCl l^-1) and a constant sensitivity in the range 0 - 30000 mg NaCl l^-1. Good recovery in the range of 90 - 105% was observed for Cd (2.0 µg l^-1) spiked into sea, estuarine and river water samples using the recommended procedure. This work proposes that using the NBN platform allows the direct monitoring and control of contaminated water for Cd by ETAAS without any chemical modification.

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