A transverse heated filter atomizer (THFA) was applied to the direct determination of Cd and Pb in urine, and
its analytical performances were investigated using a PerkinElmer SIMAA 6000 atomic absorption
spectrometer. Seronorm certified human urine reference materials and six realistic samples collected locally were
used for the method validation. The urines were diluted ten- or five-fold with 0.2% HNO3. Cd and Pb nitrate
solutions were employed as standards. Recoveries of the elements from the urine samples were investigated with
the analyte addition method. Compared to the transverse heated graphite atomizer (THGA) with a platform,
the THFA provided a significant reduction of spectral background and chemical interferences from the urine
matrix, without the use of chemical matrix modifiers, a 1.5–2 times increase of the determination sensitivity
and, therefore, a reduction of limits of detection up to 0.018 and 0.2 mg L21 for Cd and Pb, respectively. The
use of a THFA collector made from carbon fiber and a tungsten wire improved recoveries of lead and
cadmium in urine (¢92%). A sampling temperature 150 uC enabled us to skip the drying period, thus a
significantly reduced temperature program was obtained. The accuracies of the measurements of Cd and Pb in
the Seronorm urine materials were in good agreement with the recommended values: 4.1 ¡ 0.1 mg L21 of Cd
(recommended 5) and 92 ¡ 1 mg L21 of Pb (recommended 85). The lifetime of the THFA for Pb determination
was longer than 700 firings, with the sensitivity loss not more than 25% after 500 firings.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1000894 |
| Date | 30 April 2003 |
| Creators | Ngobeni, P, Canario, C, Katskov, DA, Thomassen, Y |
| Publisher | Journal of Analytical Atomic Spectroscopy |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | |
| Rights | CThe Royal Society of Chemistry |
| Relation | The Royal Society of Chemistry |
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