The future
How to increase precision in HPLC sample injection. Rheodyne's Tech Note 5 shows how you can maximize HPLC precision by using skillful sample injection techniques. The information is drawn from hundreds of closely controlled experiments using different types of sample injectors and different load ing methods. The 6-page summary of results is written to help both the beginner and the experienced chromatographer. The experiments yielded some surprising answers to highly practical questions. One question: How much sample must you waste to fill a sample loop "completely"? (It's more than you are likely to think.) Another question: When you are reading a syringe to judge the amount of sample being loaded, how much sample can you inject without impairing accuracy? (It's less than you may think.) Get the answers to these and other salient questions now
Send for Tech Note #5. Contact Rheodyne, Inc., PO. Box 996, Cotati, California 94928, USA. Phone (707) 664-9050.
RHEODYNE THE LC CONNECTION COMPANY
Until recently, these columns were mainly considered tools for the analy sis of complex mixtures—in other words, for samples that could not be satisfactorily separated on a packed column. The newest developments in column technology finally have start ed to convert the chemists in routine analytical laboratories to using these columns, even for relatively simple ap plications. The advantages of the thicker film, wider diameter columns in most instances are so overwhelming that it does not seem far-fetched to predict that within the next few years they will replace the packed column in most routine applications. The new developments in open-tu bular columns are, however, not re stricted to these workhorse columns. There are also many advances in col umn technology for those who are ana lyzing complex mixtures. I am think ing particularly of the small-diameter columns providing very high absolute efficiencies. We shall certainly see a more widespread application of these columns. As I discussed earlier, apart from a few reports, very little was done in the past in the field of open-tubular ad sorption columns. I believe that in the future this will also change. Many advances can also be predict ed in the GC systems in which the col umns are used. We certainly will have smaller, fully automated and dedicat ed instruments for open-tubular col umn use only, including the use of ro botics for sample preparation. We will also see increasing use of open-tubular columns in hyphenated techniques such as GC/MS and GC/FTIR. Prediction of the future is always difficult. However, I feel it is safe to say that we are finally at the thresh old of the universal acceptance of open-tubular columns in every field. With this, 29 years after their inven tion, we are finally starting to fulfill the pioneers' dreams. I have tried to survey almost 30 years of open-tubular column develop ment. It represented a nostalgic jour ney for me, surveying the activities of a generation. For many of us, these ac tivities became our whole life. It was exciting, and it was interesting. But even more important, it was fun! Based on the Chromatography Award Address, presented at the 189th National Meeting of the American Chemical Society, Miami Beach, Fla., April 28-May 3,1985
References (1) Golay, M.J.E. "Progress Report of Gas Chromatographic Experimental Work for September and October 1956"; Per kin-Elmer Corp., Norwalk, Conn., Nov. 15,1956. Reprinted on p. 3 of Ettre, L.S. "Open-Tubular Columns in Gas Chromatography"; Plenum Press: New York, N.Y., 1965.
CIRCLE 182 ON READER SERVICE CARD 1436 A · ANALYTICAL CHEMISTRY, VOL. 57, NO. 13, NOVEMBER 1985
(2) See also Ettre, L.S. In "Applications of Glass Capillary Gas Chromatogra phy"; Jennings, W.G., Ed.; Marcel Dekker: New York, N.Y., 1981; pp. 1-47. (3) Golay, M. J.E. In "Gas Chromatogra phy (1957 Lansing Symp.)"; Coates, V.J.; Noebels, H.J.; Fagerson, I.S., Eds.; Aca demic Press: New York, N.Y., 1958; pp. 1-13. (4) Golay, M.J.E. In "Gas Chromatogra phy 1958 (Amsterdam Symp.)"; Desty, D.H., Ed.; Butterworths: London, 1958; pp. 36-55. (5) Lovelock, J.E. Nature (London) 1958, 182,1663-64. (6) Zlatkis, Α.; Lovelock, J.E. Anal. Chem. 1959,51,620-21. (7) Lipsky, S.R.; Landowne, R.A.; Love lock, J.E. Anal. Chem. 1959,31,852-56. (8) McWilliam, I.G.; Dewar, R.A. Nature (London) 1958,181,760. (9) Desty, D.H. Abh. Dtsch. Akad. Wiss. Berlin, KL Chem. Biol. 1959,9,176-84. (10) Desty, D.H.; Goldup, Α.; Swanton, W.T. In "Gas Chromatography (1961 Lansing Symp.)"; Brenner, N.; Callen, J.E.; Weiss, M.D., Eds.; Academic Press: New York, N.Y., 1962; pp. 105-38. (11) Condon, R.D. "Design Considerations of a Gas Chromatography System Em ploying High Efficiency Golay Col umns," presented at the 10th Pittsburgh Conf. Anal. Chem, Applied Spectrosco py, Pittsburgh, Pa., March 1959; Anal. Chem. 1959,31,1717-22. (12) Cieplinski, E.W.; Averill, W. "Gas Chromatographic Analysis of Essential Oils Using Golay Columns and a Flame Ionization Detector," presented at the Annual Meeting of the Inst, of Food Technologists, Miami Beach, Fla., June 11,1962. GC Applications No. GC-AP002; Perkin-Elmer Corp.: Norwalk, Conn., 1962. (13) Ettre, L.S.; Averill, W.; Kabot, F.J. "Gas Chromatographic Analysis of Fatty Acids," GC Applications No. GC-AP001; Perkin-Elmer Corp.: Norwalk, Conn., 1962. (14) Desty, D.H.; Haresnape, J.N.; Whyman, B.H.F. Anal. Chem. 1960,32, 302-4. (15) Kreyenbuhl, A. Bull. Soc. Chim. France 1960,2125-27. (16) "Discussion on Capillary Columns." In "Gas Chromatography (1961 Lansing Symp.)"; Brenner, N.; Callen, J.E.; Weiss, M.D., Eds.; Academic Press: New York, N.Y.,1962; p. 560. (17) Averill, W. In "Gas Chromatography (1961 Lansing Symp.)"; Brenner, N.; Callen, J.E.; Weiss, M.D., Eds.; Academ ic Press: New York, N.Y., 1962; pp. 1-6. (18) Novotny, M.; Zlatkis, A, Chromatogr. Rev. 1971,14,1-44. (19) Alexander, G. Chromatographia 1980, 13,651-60. (20) Jennings, W. "Gas Chromatography with Glass Capillary Columns"; Academ ic Press: New York, Ν.Υ., 1st ed. 1978, 2nd ed. 1980. (21) Dandeneau, R.D.; Zerenner, E.H. J. High ResoL Chromatogr. /Chromatogr. Commun. 1979,2, 351-56. (22) Jennings, W. "Comparisons of Fused Silica and Other Glass Columns in Gas Chromatography"; Huthig Verlag: Hei delberg, 1981. (23) Teranishi, R.; Mon, T.R. Anal. Chem. 1964,36,1491-92. (24) Kugler, E.; Kovâts, E. Helv. Chim. Acta 1963,46,1480-1513, (25) Kovâts, E. Helv. Chim. Acta 1963,46, 2705-31. (26) Jentzsch, D.; Hôvermann, W. "Die Anwendung von Makro-Golay Sâulen in der Gaschromatographie," No. 19-GC; Bodenseewerk Perkin-Elmer & Co.: Ueberlingen, 1962. (27) Jentzsch, D.; Hôvermann, W. In "Gas
