Mixture A, % Mixture 8. % RESULTSRecently we showed that sulfonation of n-toluenesulfonic acid in fuming sulfuric acid leads to the formation of 2,5-, 3,4-, and 3,5-toluenedisulfonic acid (11). It was there-(22) H. This paper describes a compact inductively coupledtype of source has been eliminated, and pneumatic nebuplasma-optical emission system for the trace determinalization is employed in place of the more elaborate ultration of metallic elements in solution. Theoretical consid-sonic method. Some characteristics of the plasma are erations are presented to determine operating parameters reported. Detection limits are in the range 0.1 -1 0 ng/ml which agree well with the empirically determined values.for most elements studied. The present facility is readily The aerosol desolvation system commonly used with this adaptable to simultaneous multielement trace analysis.

Optical Emission SpectroscopyCombustion flames provide a remarkably simple means for converting inorganic analytes in solution into free atoms. It is only necessary to introduce an aerosol of the solution into an appropriate flame, and a fraction or all of the metallic ions in the aerosol droplets are eventually converted into free atoms. Once the free atoms are formed, they may be detected and determined quantitatively at the trace

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Spatially resolved radial excitation temperatures and radial electron density distributions experienced by analyte species in the observation zone of 15 to 25 mm above the load coil of a toroidally shaped, inductively coupled argon plasma are presented and related to the analytical performance of these plasmas. A comparison of radial temperatures measured with support gas (Ar I) lines and with a typical analyte thermometric species (Pe I) at 15 mm above the load coil is given. Radial (Fe I) excitation temperatures obtained at three observation heights are compared for aerosol carrier flows of 1.0 and 1.3 liters/min. The addition of a large amount of an easily ionized element (6900 µg of Na per ml) did not significantly change Fe I excitation temperature distributions at the respective aerosol carrier flows and observation heights. A comparison of radial electron density distributions measured with Saha-Eggert ionization and with Stark broadening methods is given for an observation height of 15 mm above the load coil. The differences between electron density values obtained by these methods is discussed. The effect of addition of 6900 µg of Na per ml on Saha-Eggert electron density distributions at three observation heights is also discussed.