Analytical evaluation of a tungsten coil atomizer for cadmium, lead, chromium, manganese, nickel and cobalt determination by electrothermal atomic absorption spectrometry

✍ Scribed by C.G. Bruhn; F.E. Ambiado; H.J. Cid; R. Woerner; J. Tapia; R. Garcia

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 940 KB
• Volume: 306
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(95)00002-h

✦ Synopsis

The analytical performance of an unenclosed tungsten coil atomizer operating in Ar-H, (9O:lO) was assessed by electrothermal atomic absorption spectrometry (ETAAS) for the determination of pg to ng levels of Cd, Co, Cr, Mn, Ni and Pb in liquid samples. A three-steps low power unit provided the heating programme for the tungsten coil with dry, pyrolysis and vaporization-atomization as sequential steps, and shortlived absorption signals (Ml-250 ms) were produced with an analysis time of 100 s. Parameters studied were the current applied to the ceil; temperatures and duration of the three heating steps; purge gas flow rate; coil alignment in the radiation beam; and sample volume. Under optimized conditions, linear working ranges extended between O-2.0 pg 1 -' for Cd and O-100 pg 1-l for Ni and Pb, and characteristic masses were between 0.3 pg (Cd) and 14 pg (Pb). Within-day reproducibility (relative standard deviation) of measurements varied between 2.2% (Cr) and 7.5% (Pb), and between-day was < 8% (Pb) in the analyte's linear working ranges, being acceptable for manual sample introduction used in this atomizer. Detection limits (3~~~) were in the range 0.6 pg (Cd)-23 pg (Pb).