Gohy h a suggested the use of the performance indcx (4) to mcasure the performance of a column run at o p t.imum flow. A theoretical limit oi 0.1 poise has been calculatrd for the ideal rolumn. An analysis of Cr to C . cyclopa.m.ffinsand aronmtics, run on a lis-foot poly(propylenr glycol) eapilhry, s h o w a sqmmtioii of I I I - and p x>-liw io lrss thnn 25 niiiiutrs (Figure 11). This separation is almost iniposaiblc on a packed column, run under the most ideal conditions within this time limit. The o-xylene peak has a performance index of 0.87, lrss t1ia.n a factor of tm from the t.heoretica1 limit. I n bhe past, resolution and theoretical plutrs hare been the mom usual \rays of calculating efficiencies. The resolution of the o-xylene peak ip 110 as nirasured by: R = - t-, - 1. Al>
where t, and t, are the elution times of thv o-x!-lene and air peaks, r w p e c t i d y , ttnrl Afz is the band xidth measured a t lialf-height. The measnrement of the uumhrr of theoretical plates as de.srrihed hy Keulcmans (7) is over 100,0. A11 rzpcrimental results aere ohtainrd using a Perkin-Elmer JIodel 154-C Vapor Fractometer with Golajcolumn-ionization detector attachment (Figure 12). The Golay columns and the new ionization detectors place a nen- and most unique sjxtem in the bands of the analytical chenust. Analysis by gas chromatography. may begin in fields untouched hy present instrumentation. Thr Golay column s n t r m does not
Figure 12. Golay columnionization detector attachment installed in a PerkinElmer Model 154-C Vapor Fractometer
make present packed eolunm systems and thermal conductivity detectors obsolete; rather the ti7-o coniplenlent each other and proride a pn\\.erful analytical ton1 for the analysis of chemical compounds by gas chromatography. LITERATURE CITED
(1) Desty, D. H., Goldup, A., Swmton, W. T., :\bfure 183, 10i (1959). (2) Golay, 11. J. E., ASAL. CHEU. 29, 928 (1957). (3) Golar ;;+ \I. J. E., in “Gas Chromatography, J. Coates, ed., p. 1, Aeademic Reria, %em- Y?rk, 1958. (4) Golay, M. J. E., m “Gas Chromatoeraphy,” D. H. Desty, ed., p. 36, .4cademic Press, h N York, 1958. (5) Golay, li. .I. E., Salitrr 180, 435 (195i).
.
(ti) Golay, 11. J. E., Symposium on Gas
Chromatography, Amsterdam, Holland, ,n=Q LilUO.
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