1996 年 45 巻 5 号 p. 232-239
A radiofrequency Ar discharge lamp with a hot electrode, radiofrequency atomization/excitation source (R-FAES) , has been developed for direct determinations of trace elements in solid samples by atomic emission spectrometry In this work, a He RFAES was developed to attain higher excitation temperatures. Among the advantages of the RFAES is the capability of direct simultaneous determinations of elements including halogens in solid samples. At the center of a stainless-steel cylinder, a tantalum cup loaded with a small size sample (5-10 μl or mg) was located and served as a discharge electrode. When an r.f. He plasma was formed between the tantalum cup and the grounded cylindrical enclosure under a reduced pressure, the cup was con-currently heated to a high temperature, owing to the r.f. power dissipation. As a consequence, the sample loaded in the cup was atomized and excited in the He plasma. Compared with graphite, tantalum was effec-tive to attain higher cup temperatures (>2300°C). Basic characteristics and analytical performance were evaluated with standard solutions. The RFAES was successfully applied to simultaneous direct determina-tions of elements including Cl in a NIST standard reference material of biological matrix, SRM 1571 Orchard Leaves.
