SPECIAL REPORT
Analytical Chemistry Summer Symposium for 1966 Reported by Roy A. Keller, Program Chairman Department of Chemistry, University of Arizona, Tucson, Arizona
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CONTRAST BETWEEN t h e m a -
-*- terial presented a t the 19th Annual Summer Symposium on A n a lytical Chemistry titled " S e p a r a tion Techniques" held a t the University of Alberta, Edmonton, Alberta, C a n a d a , J u n e 1966, and t h a t presented under the same title sixteen years ago a t Ohio S t a t e U n i versity (1) will likely d r a w t h e charge t h a t a misnomer h a s been applied t o one or the other. Of the thirteen papers read in 1950, only LeRosen dealt with chromatography per se, Craig discussed p a r t i tion chromatography a n d countercurrent distribution, and Tompkins and Schubert treated ion exchange. I n his keynote paper, M . G. Mellon devoted eighteen lines t o w h a t might then have been called chrom a t o g r a p h y . T h e remainder of the papers concerned analytical distillation, precipitation, electrolytic deposition, a n d extraction. T h e feeble cries of gas chromatography (GC) were to wait two years for the resounding postnatal slap of J a m e s and M a r t i n . Techniques which later were "recognized" as thin layer chromatography ( T L C ) were then b u t bizarre modifications of column techniques. I n 1966 twenty-four of t h e twenty-eight papers dealt with chromatography or techniques associated with i t and of these, thirteen concerned G C while four were on T L C . T h e not wholly unjust accusation of prejudice on t h e p a r t of t h e program chairman can partially be refuted by the rebuttal t h a t Chemical and Engineering News recently reported chromatography second to spectros-
copy in the number of investigators engaged. I t is also interesting t h a t three participants a t the 1950 symposium also read papers a t E d m o n ton and all are now employing this technique. T w o changes of concept a r e a p parent on comparing the meetings. I n 1950 Mellon defined separation as ". . . the process employed t o remove t h e desired constituent from the range of action of t h e interférer." This concept implies a preexisting knowledge of the composition of the sample and a value judgment of w h a t is desirable and w h a t is a n interférer. Separation techniques today, especially chromatographic, a i m t o impartially separate all components equally well, discard few or none, a n d do this with little prior knowledge beyond the class of compounds present, e.g., steroids, hydrocarbons, etc, or a knowledge of their number. T h e second concept is t h a t n o chemical change of t h e components occurs during separation. T h e second symposium is also characterized b y the minute sample size a n d e m phasis on organic compounds, p a r ticularly t h e complex molecules of biological origin. E . C. H o r n i n g described t h e a u t o mated G C analysis of t h e major h u m a n u r i n a r y steroids. T h e urine sample is first fractionated b y colu m n or thin layer chromatography, the steroids are converted t o t h e MO—TMSi derivative, and chromatographed in the gas phase on SE-30 both isothermally and with tempera t u r e programming. Steroid identification was b y m a s s spectrome-
try, deemed a necessity and n o t a frill. T h e impatience of m a n y biochemists t h a t G C steroid separations have not been directly applied to biological samples was met with displays of chromatograms of 24-hr urine samples of individuals t a k i n g steroidal a n d non-steroidal drugs, cases of overproduction or underutilization of dehydroisoandrosterone (which is often associated with adrenal tumors or testicular insufficiency) a n d microgram urinary samples of t h e new born, full term a n d p r e m a t u r e (which showed the voiding of the mother's steroids a n d change in t h e infant steroid p a t t e r n which accompanied tissue changes). Quantitative analysis b y temperature programmed techniques with flame ionization was satisfactory for reference compounds b u t was not entirely suitable with urine specimens. C. Gehrke summarized quantitatively the i m p o r t a n t factors in the G C of some 18 amino acids—i.e., the conversion t o a volatile derivative, concentration, time a n d temperature stability, volatility, reactivity with the support, and retention and molar response factors. Coupled and heterogeneous mixed bed colu m n s were used. H i s results were a convincing promise of reliable quantitative G C of amino acids, each in nanogram quantities. R e sults for bovine serum albumin and k a p p a casein hydrolysates were equivalent t o those of t h e SteinMoore procedures, as were the determinations of lysine in h a y a n d corn. M . R . Sahasrabudhe displayed a complex gas chromatogram
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