A capillary supercritical fluid chromatograph (SFC) was coupled to a surface-wave-sustained microwave-induced plasma (MIP) sustained with a surfatron. The chromato-

Novel carbon clusters isolated in the solid phase have been characterized by electron ionization (EI) mass spectrometry. The crystalline material contains the Cso and C70 molecules in a ratio of 37:l. Both of these molecules form singly charged ions that appear at mlz 720 and 840, respectively, and doubly charged ions that appear at mlz 360 and 420, respectively. Only the Cm molecule produces the triply charged species, at rnlz 240. Cso undergoes fragmentation by losing successive multiples of C2 through CI6. The C,o molecule only loses the fragments Ci and C4. Collisionally activated decomposition of these molecules in the first field-free region did not reveal any more extensive fragmentation than was observed under EI conditions.The existence of an exceptionally stable carbon cluster containing 60 carbon atoms was first reported in 1985 by Smalley and coworkers' thereby marking the beginning of the study of a new form of carbon. In order to account for the unique stability of the C, molecule, a spherical, highly symmetrical, truncated icosahedral structure was proposed. The C, structure was assigned 60 vertices and 32 faces, 12 of which are pentagons and 20 of which are hexagons, thus following the model of a geodesic dome; this similarity led to the name 'buckminsterfullerene', in honor of the architect who first designed this structure, and hence, related members of this new class of carbon compounds are called 'fullerenes'.'Theoretical studies on structure of C, and the fullerenes in general have made predictions of the 'magic numbers' for these cluster^^.^ and discussed their poten-'tial involvement in soot f~rmation.',~ Interestingly, all of the experimental work on these clusters has been done in situ in the mass spectrometer after pulsed-laser vaporization of graphite and subsequent formation of supersonic carbon-cluster beams7 It seems reasonable that many interesting experiments could be performed, including analysis by classical electron ionization (El) mass spectrometry, if purified CW and the other fullerenes were avaiIable in the solid form.The recent publication of a synthetic method for the preparation and isolation of C, in purified form makes available quantities of material needed for a determination of the physical and chemical properties of 'buckminsterfullerene'.* The infrared and ultraviolet absorption spectra of the synthetic C , molecule provide evidence for the presence of a spherical, aromatic structure for the C , cluster.' This sample has also been examined for the first time using EI mass spectrometry and the results of this analysis are presented herein. EXPERIMENTALA model 90 double-focusing mass spectrometer (Finnigan MAT, Bremen, Germany) with a BE configuration was used in all of the experiments. The sample, prepared as described elsewhere,* was introduced into the Author to whom correspondence should be addressed. mass spectrometer using the direct-insertion probe with a heating rate of 2"C/s from ambient temperature to 300°C. The El mass spectrometry conditons were as follow...

A microwave-induced plasma (MIP) sustained In helium Is evaluated as an element-selective detector for capillary supercritical fluid chromatography (SFC). The plasma source, a surface-mlcrowave-lnduced plasma (surfatron), Is described. Optimal plasma conditions Including viewing position, helium flow rate, and applied microwave power are discussed for sulfur emission In the near-infrared spectral region. In addition, the effects of two common mobile phases (C02 and N20) on plasma stability, sensitivity, and spectral background from 200 to 1100 nm are assessed. Although the plasma was evaluated principally for use with SFC, much of the discussion Is relevant to Its application as a gas chromatographic detector.Capillary gas chromatography (GC) and capillary liquid chromatography (LC) possess inherent liabilities that make them unsuitable for many types of separations. The former is ultimately restricted by the limited volatility and thermal lability of many organic compounds. The latter is restricted

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51-Deoxy-5t-methylthioguanos~ne (MTG) has been identified in human urine by combined gas chromatography/ mass spectrometry. Preliminary identification of MTG in the urine of a lung cancer patient was based upon mass spectral comparisons of the trimethylsilylated (TMS) urinary component to both MTA-(TMS) and guanosine-(TMS) 5. Structural confirmation was obtained by comparing the mass spectral and chromatographic characteristics of authentic MTG to those of the urinary component.