the fourth international gas chromatography symposium

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ANALYTICAL CHEMISTRY The Fourth International Gas Chromatography Symposium Hamburg, Germany—A 10-Year Anniversary by Richard S. Juvet, Jr. Department of Chemistry, and Chemi- cal Engineering University of Illinois, Urbana, Ill. T EN YEARS AGO in 1952, A. T. James and A. J. P. Martin published a paper entitled, "Gas-Liquid Partition Chromatography." This paper was destined to initiate one of the most actively investigated areas of analytical chemistry and to influence the research of scientists in all fields of chemistry. The Fourth International Gas Chro- matography Symposium, marking the tenth anniversary of this important dis- covery, was held June 13-16 in the beautiful new Auditorium Maximum of Hamburg State University. This is the newest University in the German Federal Republic and is situated in the largest industrial city in Federal Germany. The symposium attracted 694 registrants, an increase in attend- ance of 24 per cent over the previous International Symposium. Of these, 326 were from Germany and the Netherlands, 154 from Great Britain, 32 from the United States, and 14 from the Soviet bloc. Four registrants came from as far away as Australia. The symposium was organized by the Analytical Chemical Division of the Gesellschaft Deutscher Chemiker and the Gas Chromatography Discussion Group under the auspices of the Hydro- carbon Research Group of the British Institute of Petroleum. Previous Eu- ropean symposia have been held in London (1956), Amsterdam (1958), and Edinburgh (1960). Welcoming addresses were presented by Dr. H. Kienitz, Chairman of the Analytical Chemistry Division of the Gesellschaft Deutscher Chemiker; Dr. W. Drexelius, representative of the Senate of the City of Hamburg; and Dr. R. Sieverts, Rector of Hamburg State University. Following these ad- dresses, opening lectures were pre- sented by early workers in the field of chromatography, R. Kuhn, A. J. P. Martin, and A. "V. Kiselev. Kuhn dis- cussed the development of a separation process; Martin, in keeping with his reputation as a prophet of future devel- opments, discussed future possibilities in microanalysis and pointed out the Dr. A. J. P. Martin, Nobel Prize winner for his discovery of partition chroma- tography, is shown speaking on fu- ture possibilities in microanalysis at the 4th International Gas Chroma- tography Symposium need to develop micro hands and other micro instrumentation to handle the micro samples with which chemists of the future may be called upon to deal ; and Kiselev reviewed some adsorption studies, most of which had been carried out in Russia. One day each was devoted to sessions on Theory, Apparatus and Technique, and Applications. Thirty minutes were allowed each paper for presentation and discussion. The 30 papers were ap- proximately evenly distributed between the German and English languages. English preprints were mailed to all registrants prior to the symposium al- lowing time for preparation of con- sidered contributions to the discussion; however, spontaneous contributions were also encouraged. An hour-long panel discussion, opened by two short introductions, was also presented each afternoon. These included sessions on qualitative and quantitative aspects of GC and preparative-scale GC. Both the regular sessions and the panel dis- cussions will appear in the "Proceed- ings," of the Hamburg Symposium to be published by the end of this year. Several informal discussions of 1 to 2 hours duration were organized to run concurrently with the regular scheduled sessions. Although these discussions will not appear in the Symposium Pro- ceedings, the free exchange of ideas given at these sessions was often par- ticularly valuable. Informal discus- sions were scheduled on trace analysis, inorganic analysis including transition metal halides, programmed tempera- ture GC, theory, flavor and essential oil analysis, the design and operation of detectors, and capillary column tech- nology. Theory The session on theory was opened by Khan who presented a nonequilibrium theory of capillary columns and de- rived an equation for HETP having identical form to the - Golay equation but including an additional term ac- counting for interfacial resistance, thus eliminating the restriction assuming dynamic equilibrium at all points within the column. Several papers on adsorption chro- matography and the measurement of heats of adsorption and adsorption iso- therms were presented. Petrova, Khrapova and Shcherbakova reported a study of physico-chemical adsorption characteristics by GC methods. The rapidity with which heats of adsorption can be measured by GC compared with the classical calorimetric method was emphasized. Huber and Keulemans compared the theoretical separating efficiency of gas solid and gas liquid chromatography in a paper- on non- linear ideal chromatography and the potentialities of linear gas solid chro- matography. Adsorption isotherms were constructed directly from chroma- tograms obtained with adsorption col- umns demonstrating the validity of the theory developed. C. G. Scott meas- ured the heats and standard entropies of adsorption for η-heptane, iso-octane, cyclohexane, and benzene on alumina modified by heating at elevated tem- peratures with up to 40 weight per cent sodium hydroxide. The alumina- sodium hydroxide mixture, when used as a column packing material, gave symmetrical peaks for hydrocarbon NEWS VOL. 34, NO. 10, SEPTEMBER 1962 · 7 7 A

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Page 1: The Fourth International Gas Chromatography Symposium

ANALYTICAL C H E M I S T R Y

The Fourth International Gas Chromatography Symposium Hamburg, G e r m a n y — A 10-Year Anniversary

by Richard S. Juvet, Jr. Department of Chemistry, and Chemi­cal Engineering University of Illinois, Urbana, Ill.

TEN YEARS AGO in 1952, A. T. James and A. J . P . Mar t in published a

paper entitled, "Gas-Liquid Part i t ion Chromatography." This paper was destined to initiate one of the most actively investigated areas of analytical chemistry and to influence the research of scientists in all fields of chemistry. The Four th International Gas Chro­matography Symposium, marking the tenth anniversary of this impor tant dis­covery, was held June 13-16 in the beautiful new Auditorium Maximum of Hamburg State University. This is the newest University in t h e German Federal Republic and is situated in the largest industrial city in Federal Germany. The symposium at t racted 694 registrants, an increase in a t tend­ance of 24 per cent over the previous International Symposium. Of these, 326 were from Germany and the Netherlands, 154 from Great Britain, 32 from the United States, and 14 from the Soviet bloc. F o u r registrants came from as far away as Australia.

T h e symposium was organized by the Analytical Chemical Division of the Gesellschaft Deutscher Chemiker and the Gas Chromatography Discussion Group under the auspices of the Hydro­carbon Research Group of the British Ins t i tu te of Petroleum. Previous Eu­ropean symposia have been held in London (1956), Amsterdam (1958), and Edinburgh (1960).

Welcoming addresses were presented by Dr . H. Kienitz, Chairman of the Analytical Chemistry Division of the Gesellschaft Deutscher Chemiker; Dr . W. Drexelius, representative of the Senate of the City of H a m b u r g ; and Dr . R . Sieverts, Rector of Hamburg State University. Following these ad­dresses, opening lectures were pre­sented b y early workers in the field of chromatography, R. Kuhn , A. J . P . Mar t in , and A. "V. Kiselev. K u h n dis­cussed the development of a separation process; Mar t in , in keeping wi th his reputat ion as a prophet of future devel­opments, discussed future possibilities in microanalysis and pointed out the

Dr. A. J. P. Martin, Nobel Prize winner for his discovery of partit ion chroma­tography, is shown speak ing on fu­tu re possibil i t ies in microanalysis a t t he 4 th International Gas Chroma­tography Symposium

need to develop micro hands and other micro instrumentation to handle the micro samples with which chemists of the future may be called upon to deal ; and Kiselev reviewed some adsorption studies, most of which had been carried out in Russia.

One day each was devoted to sessions on Theory, Appara tus and Technique, and Applications. Th i r ty minutes were allowed each paper for presentation and discussion. The 30 papers were ap ­proximately evenly distributed between the German and English languages. English prepr ints were mailed to all registrants prior to the symposium al­lowing t ime for preparat ion of con­sidered contributions to the discussion; however, spontaneous contributions were also encouraged. An hour-long panel discussion, opened by two short introductions, was also presented each afternoon. These included sessions on qualitative and quant i ta t ive aspects of GC and preparative-scale GC. Both the regular sessions and t h e panel dis­cussions will appear in the "Proceed­ings," of the H a m b u r g Symposium to be published by the end of this year.

Several informal discussions of 1 to 2 hours duration were organized to run concurrently with the regular scheduled sessions. Although these discussions will not appear in the Symposium Pro ­ceedings, the free exchange of ideas given at these sessions was often par­ticularly valuable. Informal discus­sions were scheduled on trace analysis, inorganic analysis including transit ion metal halides, programmed tempera­ture GC, theory, flavor and essential oil analysis, the design and operation of detectors, and capillary column tech­nology.

Theory The session on theory was opened by

K h a n who presented a nonequilibrium theory of capillary columns and de­rived an equation for H E T P having identical form to the - Golay equation b u t including an additional te rm ac­counting for interfacial resistance, thus eliminating the restriction assuming dynamic equilibrium at all points within the column.

Several papers on adsorption chro­matography and the measurement of heats of adsorption and adsorption iso­therms were presented. Petrova, Khrapova and Shcherbakova reported a s tudy of physico-chemical adsorption characteristics b y G C methods. T h e rapidity with which heats of adsorption can be measured b y G C compared wi th the classical calorimetric method was emphasized. Huber and Keulemans compared the theoretical separating efficiency of gas solid and gas liquid chromatography in a paper- on non­linear ideal chromatography and the potentialities of linear gas solid chro­matography. Adsorption isotherms were constructed directly from chroma-tograms obtained with adsorption col­umns demonstrating the validity of the theory developed. C. G. Scott meas­ured the heats and s tandard entropies of adsorption for η-heptane, iso-octane, cyclohexane, and benzene on alumina modified b y heating a t elevated tem­peratures with u p to 40 weight per cent sodium hydroxide. The alumina-sodium hydroxide mixture, when used as a column packing material , gave symmetrical peaks for hydrocarbon

NEWS

VOL. 34, NO. 10, SEPTEMBER 1962 · 7 7 A

Page 2: The Fourth International Gas Chromatography Symposium

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solutes. Partition and adsorption of these hydrocarbon solutes on a benzo-phenone-Celite column above and be­low the melting point of the benzo-phenone was also studied. Vast differ­ences were observed not only in reten­tion volume, but also in elution order over small temperature changes near the melting point of the stationary phase.

Desty, Swanton, and coworkers re­ported that variations of solute reten­tion with choice of carrier gas and column pressure are accounted for by changes in gas phase imperfections. Retention of a hydrocarbon solute on a particular stationary phase maintaining a constant column temperature and average column pressure decreases with carrier gas in the order helium, hy­drogen, nitrogen, argon, oxygen, car­bon monoxide, and carbon dioxide.

The application of capillary columns for the accurate measurement of spe­cific retention volumes and certain other fundamental thermodynamic quantities was compared by Adlard, Khan, and Whitham with similar meas­urements carried out on packed col­umns. It was found that a repro­ducibility of about ± 1 % was ob­tained for retention volumes, similar to results found for packed columns. It was pointed out that in certain respects capillary colums are more convenient for retention volume measurements.

Freeguard and Stock discussed the advantages and disadvantages of a static method for measurement of ac­tivity coefficient data at infinite dilution and made measurements with a Mc-Bain-type balance for comparison with gas chromatographic data. Studies of the partition isotherm and the effect of mixtures of liquid phases on the ab­sorption of solute vapors were also reported.

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Page 3: The Fourth International Gas Chromatography Symposium

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Rotzsche prepared a series of cyano-alkyl substituted silicone oils and showed that the polarity, and hence the selectivity of these oils, could be changed by varying the number of ni-trile groups in the molecule.

Apparatus and Technique

An integrator making use of an analog digital converter coupled to the detector and the errors found for this arrangement were described by Kelker, Rohleder, and Weber.

Golay, Ettre, and Norem presented a theoretical treatment for a pro­grammed temperature gas chromato­graphic system operated at constant inlet and outlet pressures as well as a nomographic solution for certain prob­lems involved. Subambient pro­grammed temperature techniques were discussed by Baumann, Klaver, and Johnson. An instrument useful from - 7 5 ° to +400° C. was described. Of the several liquid phases studied for application over wide temperature ranges, the nonpolar phase, silicone oil SF 96 (50) and polar phase, nitrile silicone fluid XF-1112 [both General Electric Co., Willoughby, Ohio], were found most useful at reduced tempera­tures of —40° C. or below and yet were also useful at temperatures of 200° C. or above. Procedures for ap­plying pressure drop corrections in PTGC were evaluated and the calcula­tion of retention temperature from iso­thermal data was illustrated.

The performance of small diameter (1.5 mm.) columns packed with 3-6% hexanedione on 75- to 85-mesh firebrick and operated at high inlet pressures (up to 200 lb./sq. in.) was described by Amos and Hurrell. The columns pre­pared had efficiencies of the order of 1000 plates per meter. Sample size for a C3-C5 hydrocarbon blend was restricted to less than 0.5 μΐ. to prevent overloading the column.

The application of a catalytic com­bustion cell as a sensitive detector was suggested in a paper prepared by Schay, Székely, and Traply. These authors point out that the sensitivity of a katharometer cell should be increased several orders of magnitude by running the cell at such a temperature that com­bustion takes place and advantage may be taken of the heat of combustion rather than simply the conductivity of the gas mixture. The cell was a 10-cm. glass capillary of 0.18 ml. volume con­taining an axial mounted platinum wire, 50 μ in diameter. When the wire was treated so that a catalytic coating was produced, a temperature of 200° in the presence of air as carrier gas was suf-

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ficient for the combustion of even the slowest burning compounds. The sen­sitivity of detection was 12.5 mv. ju.gr1

seer1 for amyl alcohol and was propor­tional to the heat of combustion of the solute.

The combination of a conventional mass spectrometer with a gas chroma-tograph was shown to be useful for the identification of 37 components in a gasoline cut by Henneberg and Schom-burg. The application of characteristic masses for class identification, such as mass 91 for alkylbenzenes, was re­viewed.

Jentzsch and Hôvermann, in a study of relatively large diameter (0.5 mm. i.d., 100 m. long), coated capillary col­umns, showed that samples as large as 50 jul. could be injected, allowing the use of thermal conductivity detectors and eliminating the need for sample splitters. Two methods for reducing tailing in capillary columns were sug­gested: (1) coating the capillary with an inert, temperature-stable "interme­diate phase" such as silicone rubber SE-52 [General Electric Co.] prior to application of the stationary phase and (2) the addition of a corrosion inhibitor such as "Alkaterge T," as originally proposed by Averill at the 1961 Michi­gan State Symposium.

The hydrogen isotopes and nuclear spin isomers, ortho- and parahydrogen, ortho- and paradeuterium and hydro­gen deuteride were completely sepa­rated by Mohnke and Saffert by ad­sorption chromatography using capil­lary columns operated at 77.6° K. A 20 μ thick adsorptive layer on the inner wall of a glass capillary 80 m. in length

was prepared by etching the sealed capillary with a 17% aqueous ammonia solution at 170° for 70 hours. Neon was used as carrier gas.

Schulz presented a quantitative dis­cussion of the continuous countercur-rent separation of a number of binary mixtures. A feed mixture of isobutene (b.p., —6.9°) and n-butene-1 (b.p., —6.26°) was separated, with both com­ponents being reclaimed in greater than 99% purity, by continuous feed­ing of the mixture into the center of the column while allowing a sorption material of silver nitrate in benzyl cyanide on Sterchamol to move in a countercurrent direction to the carrier gas flow.

Kaiser and Kienitz pointed out that gas chromatographic equipment could pay for itself within a period of 10 days to 1 month when used under the right conditions in process control systems. The application of a process control unit to distillation problems was re­viewed.

Applications

T. R. Phillips and D. Neylan pre­sented a statistical study of factors af­fecting column performance in the separation of halogen and interhalogen compounds on Kel-F oils. One obser­vation, not in accordance with estab­lished theory, was that a liquid phase loading of 20% Kel-F oil on Kel-F Grade 300 molding powder gave better column performance with 50-70 mesh particles than with finer size particles while a high loading of 80% gave better

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Page 5: The Fourth International Gas Chromatography Symposium

NEWS

performance on finer particles of 70-to 80-mesh. The authors explained this result by pointing out that the support was chemically similar to the liquid phase in these experiments and cannot be regarded as inert.

A method for the determination of separation factors from unresolved two-component peaks was developed by Sideman and Giladi. A study of nitro­gen isotope enrichment was used as an application of this method. A separa­tion factor of 1.0011 for a 28/29 nitro­gen isotope mass ratio obtained experi­mentally was in good agreement with the value 1.0007 calculated from vapor pressure measurements.

A detailed description of a GC ap­paratus useful for the qualitative and quantitative analysis of microgram amounts of flavor volatiles from edible fats was given by Swoboda. Individ­ual peaks were identified with the aid of Kovats' retention index method and the determination of the carbon skele­ton by catalytic reduction of the com­ponent to its corresponding hydrocar­bon followed by GC identification of the product formed.

Schomburg reviewed the chemistry of boron alkyls and hydrides and demonstrated the value of GC for de­termining equilibrium concentrations of products formed in the transalkylation of boron alkyls, boracyclanes, and bis-borolanes.

Grant and Vaughan prepared tri-methyl silyl ethers of phenols with hexamethyldisilazane for the separa­tion of complex phenolic mixtures. Glass capillary columns coated with silicone oil MS 550 [Midland Silicones Ltd.] gave well defined symmetrical bands for silylated phenols, cresols, and xylenols boiling in the range 190-300° C.

The analysis of millimicroliter quan­tities of the permanent gases hydrogen, oxygen, nitrogen, argon, methane, car­bon monoxide, carbon dioxide, krypton, xenon, and neon was described by Berry. An ionization detector with high purity helium used as carrier gas was employed [metastable (23S) he­lium atoms, 19.8 eV energy]. The limit of detection ranged from 5 X 10~8

to 5 Χ 10-7 cc. of the permanent gases. A method for adequately purifying the helium carrier gas and the variation of detector signal with flow rate, gas pres­sure, and detector temperature were discussed in detail.

Trace analysis of hydrocarbons (up to Ce) was performed by Huyten, Rijnders and van Beersum on alumina columns containing ca. 2% water. Ap­paratus was described which is useful for direct quantitative analysis in con­centrations down to ca. 0.003 p.p.m.

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Page 6: The Fourth International Gas Chromatography Symposium

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CALENDAR OF EVENTS Aug. 29 to Sept. 5

Fifth International Congress for Electron Microscopy, Philadel­phia, Pa. Host: Electron Microscope Society of America. Con­tact: Fifth International Congress for Electron Microscopy, 7701 Burholme Ave., Philadelphia 11, Pa. Page 50 A, Nov.

Sept. 5 to 7

Symposium on Measurement of Thermal Radiation of Solids. Biltmore Hotel, Dayton, Ohio. Sponsors: U. S. Air Force, National Bureau of Standards, National Aeronautics and Space Administration. Contact: C. R. Andrews, University of Dayton, Dayton 9, Ohio. Page 53 A, June.

Sept. 9 to 14

American Chemical Society, 142nd National Meeting, Atlantic City. N . J . Page 39 A, Aug.

Sept. 10 to 15

International Symposium on Molecular Structure and Spectros­copy, Tokyo, Japan. Sponsor: International Union of Pure and Applied Chemistry and Science Council of Japan. Contact : Secretary, International Symposium on Molecular Structure and Spectroscopy, Science Council of Japan, Ueno Park, Tokyo, Japan. Page 105 A, Feb.

Sept. 16 to 20

Second Annual Conference on Pharmaceutical Analysis, Kings Gateway, Land O'Lakes, Wis. Contact: R. S. Strommen, Uni­versity of Wisconsin, Madison 6, Wis.

Sept. 16 to 22

Eighth Latin American Congress of Chemistry, Buenos Aires. Contact: Secretaria, Octavo Congreso Latino-Americano de Quimica, Casilla Correo 2153, Buenos Aires, Argentina. Page 105 A, Feb.

Sept. 17 to 19

Sept. 26 to 28

Ninth Ottawa Symposium on Applied Spectroscopy, Ottawa, Canada. Sponsor: Canadian Association for Applied Spectros­copy. Contact: Ben Farrar, J . T. Donald & Co., Ltd., 1181 Guy St., Montreal 25, Quebec. Page 63 A, March.

Practice of Gas Chromatography. Michigan State University. Sponsors: ASTM Committee E-19 and Michigan State Univer­sity. Contact: Nathaniel Brenner, The Perkin-Elmer Corp., Norwalk, Conn. Page 46 A, April.

Drawert reviewed several applica­tions of chemical reactors positioned just ahead of the chromatographic column. The analysis of the lower fatty acids in the stomach of Colo-binae monkeys was carried out· by esterification with methanol/boron tri-fluoride reagent. The esterified frac­tion was then injected directly into a calcium hydride reactor for removal of water and acids without need for prior isolation of the esters. C14-labeled al­cohols in aqueous solution were ana­lyzed by dehydration to C14-olefins in an appropriate chemical reactor and de­tection of the olefins at the column out­let with proportional counting equip­ment.

The partial thermal decomposition and cracking patterns of some 23 hy­drocarbons up to C10 were studied by Keulemans and Perry. For controlled decomposition the sample was exposed for 20 sec. to temperatures of approxi­mately 500° C , and quantitative meas­urements of the decomposition prod­ucts were made. Stability to thermal decomposition decreases in the order: double bonds, single bonds adjacent to

double bonds, single bonds. The re­producibility of cracking pattern and the influence of cracking temperature and sample size were briefly discussed.

The symposium was adjourned fol­lowing closing addresses by W. W. Brandt and C. S. G. Phillips. Although some were heard to say that much of the work presented at this symposium represented important improvements of existing technology rather than major new developments or breakthroughs, still interest remains high as judged by continually increasing attendance. Gas chromatography will undoubtedly maintain a leading position in the in­terest of analytical chemists for many years to come.

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