Properties of the cadmium determination with the platform furnace and Zeeman background correction

• Published in: Spectrochimica acta. Part B: Atomic spectroscopy 1983, Vol.38 (8), p.1157-1170
• Main Authors: Slavin, Walter, Manning, D.C., Carnrick, G., Pruszkowska, E.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Exact sciences and technology; Spectrometric and optical methods
• ISSN: 0584-8547; 1873-3565
• DOI: 10.1016/0584-8547(83)80092-5

Cadmium, previously a difficult determination in inorganic matrices with the graphite furnace, is shown to be easy to determine with the combination of the stabilized temperature platform furnace, appropriate matrix modification and Zeeman background correction. The optimized conditions were suitable for many matrices; seawater and urine were explored in some depth. Natural water samples were analyzed for Cd. The matrix modifier included ammonium phosphate and either Mg(NO 3) 2 or NaCl. Simple working curves were used. Problems associated with char losses were studied and recovery experiments were shown to expose such problems. The concept of characteristic amount, the mass of analyte that produced a 1 % absorption signal (0.0044 abs), especially using integrated absorbance data, was shown to be a very powerful diagnostic tool for graphite furnace work. The characteristic amount for Cd was 0.35 pg/0.0044 abs-s, and it varied little with variations in experimental conditions. The effect of background signals that were evolved rapidly was to disrupt the Zeeman signal. Guidance is provided in identifying and controlling these problems. The advantage of the Zeeman technique in providing improved detection limits using bright sources was explored.