Furnace programmer

Three Zeeman-based methods for the determination of cadmium in seawater were investigated. Direct determinations can be made with or without the use of a pyrolytic platform atomisation technique. The wall atomisation methods presented were considerably faster than the platform atomisation technique. For extremely low levels of cadmium, indirect methods of analysis employing a preliminary analyte extraction can be employed. Background levels are minimal in extracted samples, and the total furnace programme time was the lowest of the methods examined. 

Quartz probes fitted with thermocouples to measure the temperature, and follow the movement of the sample. Linked transducer, i.e. a linear variable density transformer to sense the probe movement and produce a related electrical signal. Sample furnace, programmers and various output devices. 

The literature on applications of electrothermal atomizers is now extremely large and, because of the details of the furnace programmes used, is well worth consulting. The tables in the Atomic Spectrometry Updates reports (see Appendix C) offer the best way of accessing this information. 

ETAAS The best settings for the furnace programme were first... 

EH Larsen. Graphite furnace atomic absorption spectrometry of inorganic and organic arsenic species using conventional and fast furnace programmes. J Anal At Spectrom 6 375-377, 1991. 

DMA instruments have furnaces programmable from — 170°C to 600°C. Frequency ranges can be varied from 0.001 to 1000 Hz, depending on the manufacturer. Probe types are the same as those for TMA. 

Two principal advantages of the probe atomization are (i) Improved control of the vapour temperature the atoms experience (ii) Rapid heating of the atomization surface to the volatilization temperature of the analyte and matrix. A comparison of typical furnace programmes for wall/platform atomization and probe atomization is given in Table 8. The probe is not in... 

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