Device for atomizing a sample for flameless atomic absorption measurements

摘要

A device for atomizing a sample for so-called flameless atomic absorption spectroscopic measurements of the type in which an electrically conducting hollow tube, into which the sample is introduced as by a central port in the side of the tube, is heated by the passage of current from electrodes contacting the ends of the tube. A protective inert gas is caused to surround the interior and exterior of the tube to exclude air to avoid oxidation of the sample tube which may be graphite. The improvement comprises introducing the protective gas into both ends of the sample tube so that it leaves the interior through the central port from which it may be sucked outside of a surrounding housing. The exterior walls of the sample tube may be provided with protective gas either by means of an auxiliary gas flow or by leading the gas from the bore around the outside of the tube before withdrawing it through the surrounding housing. By introducing the gas flow generally from the cooler ends to the hotter medial portion of the tube, decomposition products or samples are not condensed on cooler parts, from which they could later be vaporized and contaminate the atomized sample elements during subsequent analyses.