Coiling-induced secondary flow in capillary supercritical fluid

Enhanced radial mass transfer caused by secondary flow In coiled channels Is demonstrated for capillary supercritical fluid chromatography. The unique...
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Anal. Chem. 1980, 58. 2699-2704

2699

this small PAHs region were observed with the use of this column. Therefore, to improve resolution in the analysis for small PAHs, one should use longer and higher efficiency columns with more severe separation conditions such as temperatures over 60 'C and pressures of 80 kg/cm2, although that approach had not been attempted in this study. In conclusion, 11 priority pollutants, PAHs and henzo[e]pyrene, were identified in the extract sample as shown in Table I by SFC coupled with a UV multichannel detector.

ACKNOWLEDGMENT The authors wish to thank Y. Hirata and H. Ohta of Toyohashi University of Technology for their assistance in the sample preparation. Registry No. Fluoranthene, 206-44-0:pyrene, 129-00-0: benz[a]anthracene, 56-553;chrysene, 218-01-9:fluorene, 86-73-7; henzo[b]fluoranthene,205-99-2;benzo[k]fluoranthene,207-089; henzo[e]pyrene, 192-97-2;benzo[a]pyrene, 50-32-8;indenobenzo~hi]perylene.191-24-2;phen[1,2,3-cd]pyrene, 193-39-5; anthrene, 85-01-8;anthracene, 120-12-7;naphthalene, 91-20-3; dibenz(a,h]anthracene,53-70-3.

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LITERATURE CITED I,*

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Flgun 4. Measured chromatograms of PAHs with superdticsl CO, as the mobile phase. (A) Measured chromatograms of tlm extract: mobile phase. COS;presswe. 100 kglcm'; temperahre. 40 OC: peak assignments, 1 and 2. are the same as in Figure i A . (6) Three-dC mensionai chromatogram.

elute a t a similar retention time. And the spectrum a t 1.56 min can be assigned as phenanthrene, because the agreement between the filed and measured UV spectra was found. However, identification of other peaks is very difticult because of the complexity of the chromatogram and nonreliahility of the obtained UV spectra. I t is assumed that only peak 17 might be caused from anthracene, hecause the correlation number of 0.80 was obtained in the UV spectra matching process. To know the complexity of the chromatogram in this region more clearly, a contour plot was called from the data filed in the microeomputer. About 15 components can be found in this region. The separation condition of higher column temperature and lower column pressure was then examined, hut no remarkable improvements in resolution in

(1) Jones. D. G. Anal. Chem. 1985, 57. 1207A-1214A. (2) DBOSY.R. E.; Reynolds. W. D.; Nunn. W. G.: 'mu% C. A.; M o k . G. F. J . Chmmatogr. 1910. 728. 347-368. (3) Drouen. A. C. J. H.; Bliiiet. H. A. H.;DeOalan, L. Anal. m m . 1985,