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Column liquid chromatography
. trends in analvtical chemisty,
XII
col. I. no. 4.1981
MEETING REPORTS
Column Liquid Chromatography Vth Symposium on Column Liquid Chromatography, Palais des Papes, Avignon, France, 11-15 May 1981
Interlaken, Wilmington, Salzburg, Boston, and now, for the fifth InterColumn national Symposium on Liquid Chromatography, Avignon. The meetings of this scrics have, to date, been held biennially but from now on the organizing committee proposes to hold them annually, the locations alternating bctwcen Europe and the U.S.A. The next meeting will bc held in Philadelphia in June 1982. Can Modern Liquid Chromatography, i.c. HPLC, stand the pace and can liquid chromatographcrs continue to product high quality work at the ncccssary rate? There arc those who have cxprcsscd doubts about this. Most of the participants and prcscntcrs of papers arc from Europe (when the meetings arc held in Europe) or from the U.S.A. (when the meetings arc held thcrc) and only a relatively small proportion of participants are likely to attend all the meetings. Thcrc is no doubt that the quality of work presented at Avignon maintained the high standard set by previous meetings in the series. The continuance of the series was therefore more than justified and there arc cxccllent prospects for the annual meetings now planned. As has become the tradition, at recent symposia in both GC and LC, the official programme comprised plenary lectures, poster sessions, informal discussions and a comprehensive manufacturers exhibition. The venue for the meeting was the remarkable medieval Palais des Papes - lectures being held in the main Council Chamber. Some 38 plenary lectures were presented and about twice as many poster papers. All major topics in HPLC were covered: detection methods and problems; columns and column technology; retention mechanisms; applications to proteins, optical isomers, drugs, biochemicals ctc; preparative liquid chromatography. Four 0 16.5-9936/81/00W-owO/~~~,
7.5
informal discussions were held on detection problems, column technology, retention mechanisms and preparative liquid chromatography. These were scheduled for the unpromising time of 5 o’clock in the afternoon. It is a tribute to the participants and an indication of the intense interest which HPLC still commands, that all these discussions were fully attended and were never terminated due to lack of interest. They were all vigorous and informative. Perhaps the topic which stimulated the liveliest discussion and produced the greatest diversity of opinion was that of the value-or othcrwisc - of narrow bore packrd columns and open tubular HPLC columns.
Plenary lectures The highlights of the meeting were undoubtedly the plenary lectures. I was particularly interested in those lectures which presented novel ideas concerning the future dcvclopmcnt of HPLC both in terms of equipment and separation techniques. The paper presented by Harris (co-authored by Canter and Dovichi) discussed the use of thermal lens calorimetry as a basis for detection. When a focusscd laser beam passes through an absorbing liquid, the heat generated causes a change in refractive index within the beam, and consequently generates a liquid lens which defocusses the beam. Because of the high intensity of the laser beam the technique can bc highly sensitive and the indications arc that it can compete with current U.V. dctcctors. Detectors based on thermal lens calorimetry also hold the promise of having extremely small volumes. Schill presented a characteristically elegant paper (co-authored by Dcnkert and Hackzell) on reversed phase ion-pair chromatography of u.v. transparent compounds using a U.V. absorbing pairing agent. The principle of the method, which was supported by extensive data, is that any solute retained by the stationary phase as an ion pair will either displace the pairing agent from the stationary phase into the eluent or deplete the pairing agent from the eluent. Thus,
when a sample is first placed on the column there is a net adsorption or desorption of pairing agent which manifests itself as a ‘systems peak’ with a characteristic retention timr. As each solute emerges from the column it will produce its own peak which may be either positive or negative. The sum of the areas of the solute peaks must be equal to the area of the systems peak. The method is less sensitive than direct U.V. photometry for U.V. absorbing solutes but is ncverthelcss capable of dctccting nanomole quantities. However, the most spectacular developments described at Avignon came from those working with narrow bore open tubes. Thus, Tijsscn and Blucmer routed the many prophets of doom by demonstrating that 10’1 theoretical plates could bc ohtaincd in 2 h using a 5 m length of 14 p bore glass tube with an internally coated rrtentive wall. The groups of Ishii and Novotny also demonstrated substantial improvements. But the prize for the most remarkable and original paper must surelv go to Jorgenson, Arman and Guthr& who showed how current HPLC know-how could bc apphcd to clectrophorcsis. Usin,? a 1 m tube of 70 p bore, across which a potential of 30,000 V was applied, they demonstrated separations of amino acids with an cfflcicncy of 500,000 plates in 15 min. They then showed how the same equipment, which included a home-made in-linr fluorimetric detector, could bc employed to demonstrate elcctrophoretic chromatography. A column of 160 ~1bore was packed with 10 l_tparticles. This dcvrloped 31,000 plates in 20 min, giving a reduced plate height of 1.9. W’hile the principles of these methods have been known for many years they havr never before been demonstrated so convincingly in action. This paper must surely initiate a growth in intcrcst and research activity in separations where chromatographic and electrophoretic principles are combined. ,JOHK.H. KSOX
J. H. Knox is at the Department of Chemistry. Universi[v of Edinburgh, (Q1981Elsetier
Edinburgh, Scicntilic
U.K.
Publishin~Cmnpany
XII
col. I. no. 4.1981
MEETING REPORTS
Column Liquid Chromatography Vth Symposium on Column Liquid Chromatography, Palais des Papes, Avignon, France, 11-15 May 1981
Interlaken, Wilmington, Salzburg, Boston, and now, for the fifth InterColumn national Symposium on Liquid Chromatography, Avignon. The meetings of this scrics have, to date, been held biennially but from now on the organizing committee proposes to hold them annually, the locations alternating bctwcen Europe and the U.S.A. The next meeting will bc held in Philadelphia in June 1982. Can Modern Liquid Chromatography, i.c. HPLC, stand the pace and can liquid chromatographcrs continue to product high quality work at the ncccssary rate? There arc those who have cxprcsscd doubts about this. Most of the participants and prcscntcrs of papers arc from Europe (when the meetings arc held in Europe) or from the U.S.A. (when the meetings arc held thcrc) and only a relatively small proportion of participants are likely to attend all the meetings. Thcrc is no doubt that the quality of work presented at Avignon maintained the high standard set by previous meetings in the series. The continuance of the series was therefore more than justified and there arc cxccllent prospects for the annual meetings now planned. As has become the tradition, at recent symposia in both GC and LC, the official programme comprised plenary lectures, poster sessions, informal discussions and a comprehensive manufacturers exhibition. The venue for the meeting was the remarkable medieval Palais des Papes - lectures being held in the main Council Chamber. Some 38 plenary lectures were presented and about twice as many poster papers. All major topics in HPLC were covered: detection methods and problems; columns and column technology; retention mechanisms; applications to proteins, optical isomers, drugs, biochemicals ctc; preparative liquid chromatography. Four 0 16.5-9936/81/00W-owO/~~~,
7.5
informal discussions were held on detection problems, column technology, retention mechanisms and preparative liquid chromatography. These were scheduled for the unpromising time of 5 o’clock in the afternoon. It is a tribute to the participants and an indication of the intense interest which HPLC still commands, that all these discussions were fully attended and were never terminated due to lack of interest. They were all vigorous and informative. Perhaps the topic which stimulated the liveliest discussion and produced the greatest diversity of opinion was that of the value-or othcrwisc - of narrow bore packrd columns and open tubular HPLC columns.
Plenary lectures The highlights of the meeting were undoubtedly the plenary lectures. I was particularly interested in those lectures which presented novel ideas concerning the future dcvclopmcnt of HPLC both in terms of equipment and separation techniques. The paper presented by Harris (co-authored by Canter and Dovichi) discussed the use of thermal lens calorimetry as a basis for detection. When a focusscd laser beam passes through an absorbing liquid, the heat generated causes a change in refractive index within the beam, and consequently generates a liquid lens which defocusses the beam. Because of the high intensity of the laser beam the technique can bc highly sensitive and the indications arc that it can compete with current U.V. dctcctors. Detectors based on thermal lens calorimetry also hold the promise of having extremely small volumes. Schill presented a characteristically elegant paper (co-authored by Dcnkert and Hackzell) on reversed phase ion-pair chromatography of u.v. transparent compounds using a U.V. absorbing pairing agent. The principle of the method, which was supported by extensive data, is that any solute retained by the stationary phase as an ion pair will either displace the pairing agent from the stationary phase into the eluent or deplete the pairing agent from the eluent. Thus,
when a sample is first placed on the column there is a net adsorption or desorption of pairing agent which manifests itself as a ‘systems peak’ with a characteristic retention timr. As each solute emerges from the column it will produce its own peak which may be either positive or negative. The sum of the areas of the solute peaks must be equal to the area of the systems peak. The method is less sensitive than direct U.V. photometry for U.V. absorbing solutes but is ncverthelcss capable of dctccting nanomole quantities. However, the most spectacular developments described at Avignon came from those working with narrow bore open tubes. Thus, Tijsscn and Blucmer routed the many prophets of doom by demonstrating that 10’1 theoretical plates could bc ohtaincd in 2 h using a 5 m length of 14 p bore glass tube with an internally coated rrtentive wall. The groups of Ishii and Novotny also demonstrated substantial improvements. But the prize for the most remarkable and original paper must surelv go to Jorgenson, Arman and Guthr& who showed how current HPLC know-how could bc apphcd to clectrophorcsis. Usin,? a 1 m tube of 70 p bore, across which a potential of 30,000 V was applied, they demonstrated separations of amino acids with an cfflcicncy of 500,000 plates in 15 min. They then showed how the same equipment, which included a home-made in-linr fluorimetric detector, could bc employed to demonstrate elcctrophoretic chromatography. A column of 160 ~1bore was packed with 10 l_tparticles. This dcvrloped 31,000 plates in 20 min, giving a reduced plate height of 1.9. W’hile the principles of these methods have been known for many years they havr never before been demonstrated so convincingly in action. This paper must surely initiate a growth in intcrcst and research activity in separations where chromatographic and electrophoretic principles are combined. ,JOHK.H. KSOX
J. H. Knox is at the Department of Chemistry. Universi[v of Edinburgh, (Q1981Elsetier
Edinburgh, Scicntilic
U.K.
Publishin~Cmnpany