ISSN:
1436-5073
Schlagwort(e):
Key words: Cadmium; sediment slurries; tungsten and rhodium; permanent modifier; electrothermal atomic absorption spectrometry.
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract. A tungsten-rhodium coating on the integrated platform of a transversely heated graphite atomiser (THGA) was used as a permanent chemical modifier for the determination of Cd in sediment slurries by electrothermal atomic absorption spectrometry. Slurries were ultrasonicated during 20 s before being delivered to the previously W-Rh treated platform. The permanent W-Rh modifier remains stable by approximately 250 measurements when 20 μl of slurries containing up to 1.0% m/v are delivered into the atomiser. In addition, the permanent modifier increases the tube lifetime up to 720 analytical firings. Also, when the W-Rh permanent modifier was employed, there was less variation of the slope of the analytical curves during the total atomiser lifetime, resulting in a decreased need of re-calibration during routine analysis, increasing the sample throughput. The atomiser lifetime was limited to the THGA wall durability, because the W-Rh treated platform was intact after more than 720 analytical firings. Detection limits based on integrated absorbance for 1.0% m/v slurries were 1.5 ng g−1 Cd for 250 μg W +200 μg Rh permanent modifier and 11.5 ng−1 Cd for 5 μg Pd +3 μg Mg(NO3)2. Results for the determination of cadmium in sediment slurries using the W-Rh permanent modifier were in agreement with those obtained with dissolved sample solutions by using Pd + Mg(NO3)2, since no statistical differences were found by the paired t-test at the 99% level.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s006040070063
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