News Theflexibilityproposal follows months of discussion between OW and the affected community, and comes as a concerted effort—within and outside the agency—is underway to change EPA's approachtoanalytical methodologies (see Anal. Chem. 1996,68,733 A-37 A). In theory, flexibility could lead to less expensive analyses and spur the sale of new types of analytical instrumentation. The OW proposal, however, falls short of what some see as the ultimate goal of introducing performance-based methods that give analysts the freedom to use any method that meets certain data quality objectives and quality controls. Comments on the proposal are due to EPA this month
PEOPLE
King wins Wiley Award Jerry King, lead scientist at the USDA's National Center for Agricultural Utilization Research, has been awarded AOAC International's Harvey W. Wiley Award for significant advances in analytical methodology. Wiley was instrumental in establishing laws protecting the purity of foods, drugs, and cosmetics. King is being honored for his work in SFE and SFC with compounds such as lipids, pesticides, volatiles, and semivolatiles. The award carries a cash prize and King will speak at a symposium in his honor at the association's annual meeting in September
Benedetti-Pichler nominations The American Microchemical Society requests nominations for the 1998 BenedettiPichler Award, which recognizes outstanding achievements in microanalytical chemistry. The award consists of a plaque and expenses to attend the Eastern Analytical Symposium in Somerset, NJ, in November, to receive the award. Eligibility is not restricted to society members, and past nominees may be renominated with updated information. Documents should include three nominating letters and should be sent to Robert G. Michel, Dept. of Chemistry, University of Connecticut, 215 Glenbrook Rd. Storrs CT 062694060 (860-486-3143;
[email protected]). The deadline is Oct 24 284 A
Michael Tswett and his method This month marks the 125th anniversary of the birth of Michael S. Tswett, who first developed chromatography in the early part of this century. Tswett, a botanist by training, was interested in the chemical composition and biological function of plant pigments. To study these materials, he needed a simple method to separate the pigments—simpler than the complicated liquid-liquid partition procedures being used. Tswett's papers clearly indicate that he performed numerous separation experiments to find suitable phase systems for his new technique based on adsorption phenomena. Nevertheless, there are only three publications in which he described the work: a 1903 lecture presented in Warsaw, Poland (Proc. Warsaw Soc. Nat. Sci.c Biol. Sect., 1903,XIVN.. 6); a 1906 paper (Ber. Deut. Bot. Gesellsch. 1906624,384); and d 1910 book on biological pigments (Khromofilly v Rastitel'nom i Zhivotnom Mire (Chromophylls in the Plant and Animal World) Karlassiakoff Warsaw 1910). The Warsaw lecture gave the first description of the new technique but without illustrations. Tswett outlined a ligroin extraction of green leaves (e.g., dead nettle or plantain) and elution of material on a bed of inulin: "First, a colorless liquid flows out from the bottom of the funnel (i.e., the glass column), then a yellow one (carotene), while a bright green ring forms at the top of the inulin column below which a welldefined yellow ring appears soon. On subsequent washing of the inulin column with pure ligroin both rings the green and the yellow one are considerably widened and move down the column" The inulin powder is a carbohydrate with a 2-um particle diameter; the column was packed dry, and the separation process took place "under slight pressure or suction". The separation performance was high enough to obtain the yellow eluate as a pure solution whose identity was proven to be xanthophyll alpha by UV-vis spectroscopy. The green ring could be further separated into two zones of deep bluegreen and yellow-green. Tswett must have been a skillful experimenter to dry-pack a 2-um powder with the necessary homogeneity for well-defined and undisturbed chromatographic bands In the 1906 paper, Tswett brought his method to a markedly higher performance. He recommended using calcium carbonate or sucrose as adsorbents for plant pigment separation. In the paper, he wrote: "Like
Analytical Chemistry News & Features, May 1, 1997
Michael Tswett
light rays in the spectrum, the different components of a pigment mixture, obeying a law, are separated on the calcium carbonate column and can thus be determined qualitatively and quantitatively. I call such a preparation a chromatogram and the corresponding method the chromatographic method." (Perhaps Tswett was playing witii words: "chromatography" means "color writing", and the Russian word "tswef' means "color".) The paper was accompanied by a drawing of a chromatogram showing the separated, although not yet eluted, bands of three xanthophylls and two chlorophylls (the carotenes were not retained by the stationary phase but eluted with the solvent front). The drawing revealed that the green plant pigment, chlorophyll, consists of two compounds. Tswett's work with plant pigments, however, was not accepted by the "authorities" of the time, Richard Willstatter and Leon Marchlewski. The latter condemned the chromatographic method as a "filtration experiment", which was too simple to yield scientifically sound results. In retrospect, recognition for the new technique was probably hampered because Tswett's separations could be reproduced only by careful and patient researchers. The traditional partition methods on the other hand were tedious but easier to perform. The 1910 book dealt mainly with plant physiology. In a short section, Tswett again described his chromatographic experiments but without presenting any new details of the technique. In fact, when his procedure is examined step by step, it is not really clear how he obtained his separations. He seems to have preferred step-gradient elution in which more than one solvent is used for the development of the chromatogram.
HP, which has supplied instruments to every Olympics since 1972, has taken advantage of its expertise in this field. Moreover, Cram said that athletes are still finding new, clever ways to cheat—another reason why this could remain a hot market for some time. Virtual Pittcon. What does it mean when a company reduces its Pittcon booth size by 90% from the previous year? Financial difficulties? No new products? Neither, says Varian executive vice-president Al Lauer, whose company did just that. According to Lauer, Varian took the cash savings from the booth shrinkage and invested it in their Web site (www.varian. com) to create a "virtual" Pittcon booth. "The ways we are communicating are NEWS FROM PITTCON changing," Lauer said, and Varian is heavily emphasizing the Internet. In fact, Alan Newman reportsfromAtlanta, GA Varian didn't bring all its new products to Atlanta this year, preferring to tell its Pittcon trends and story on the World Wide Web. quotes Clean slate. "Whatever you knew about Perkin Elmer three years ago— No repair calls. According to Rick forget it," said Tony White, PE's head. Chapman, president and CEO of ThermoQuest, 85% of the service calls the company The company has undergone numerous changes since White took over in 1995, receives have nothing to do with malfuncwhich has helped fuel a rapid growth in tioning instruments. "I don't know how to do experiment X" is a typical message, he the stock value. 'We generate more than says. As a result, ThermoQuestt ,lke many $25 million in cash," he said. "We have lots of money." And in case you're wonother companies, has become more involved in the scientific aspects of their cus- dering what PE is doing with all that money, Manuel Baez, the company's new tomers' problems. Chapman said that about 50% of ThermoQuest's service repre- president of analytical instruments, reported, actively looking for acquisentatives are now degreed chemists, and sitions." Also, Baez said that the company the company will work with customers on a paid basis to develop sophisticated meth- was making a major effort to grow in odologies. "It's a profitable business grow- South America. He cited Argentina Venezuela Ecuador and Mexico as key emerging rapidly." ing markets being targeted by the instruA sporting business. Think bioment manufacturer pharmaceuticals is a hot market? How about a market that is growing 50-80% a Thermo grows some more. The year? According to Hewlett-Packard offi- latest big company acquired by Thermo cials, that is what is happening in the Instrument Systems is Life Sciences, pursports testing arena; in recognition of chased this year for less than $395 milthat growth, the company has created a lion, or at a price of about 1.2 times sales. special group to service this market. Life Sciences includes trade names like According to Stuart Cram, HP's head Neslab, Spectronic, Hypersil, and Forma. of the new effort, sales are now approxi- According to Arvin Smith, head of Thermo Instrument, Life Sciences offers mately $20 million. The growth has been fueled by the establishment of test- the Thermo dynasty 32 new products out ing laboratories in nearly every country, of 35 gained in the acquisition. Smith called them application-superior rather including such cash-starved states as Vietnam and Albania. "No country wants than technology-superior products. In the short run Life Sciences will remain whole to be embarrassed at the Olympics by and operate as an independent entity undrug use," Cram said. This sentiment der the Thermo flag. In addition to Life has led to many countries testing their Sciences Thermo made eight other acquipromising athletes all the time an efsitions since the last Pittcon and has balfort that requires high-end analytical looned to become a $1 5-billion-a-year instruments such as gas and liquid business chromatographs.
Acceptance of the chromatographic method was slow because Tswett's work was not published in journals read by chemists, the experimental descriptions lacked sufficient detail, and the new technique required careful work. Also, work on the technique was disrupted by World War I (1914-18) and Tswett's untimely death in 1919. Nevertheless, it was successfully used in 1906 by G. Kranzlin (Germany), in 1912 by C. Dhere (Swiizerland), and in 1913 by L. S. Palmer rU.S.). Today, chromatography is one of analytical chemistry's most powerful tools. Veronika R. Meyer
Chicago out as Pittcon site? Conflicts over scheduling have led the Pittcon organizing committee to switch the year 2000 meeting from Chicago to New Orleans; the 2004 date slated for the Joanne Smith, Pittcon'97president windy city is also in jeopardy. According to Joanne Smith, ,his year's Pittcon president, the convention officials thought the exhibition was set for dates in March for both years, but Chicago convention officials booked Pittcon into McCormick Place's new South Hall in February. Exhibitors, said Smith, were unhappy about the earlier meeting time because of the potential for bad weather. "Given the high cost and difficulty of mounting a show in the city we have to m.ke it convenient for everyone " she said "February is too high a risk" The Pittcon committee was still planning to talk to the Chicago organizers about the 2004 date, but Smith was not optimistic about a solution. In fact, relations between Pittcon and Chicago officials are strained over charges of bad faith. Nevertheless, she said that Pittcon "hasn't given up on the city." The 2000 meeting in New Orleans is now set for March 13-16. The question of where to hold the convention has become a vexing problem for Pittcon organizers. By eliminating Chicago, the meeting will remain in the southern United States for the next few years, in either New Orleans or Orlando. Most other cities cannot offer the roughly 800,000 to 1 million square feet of convention hall space needed for the event 'We would like very much to get back to the Northeast," said Smith. The 1990 New York City meeting held Pittcon's highest attendance record until last year's Chicago exhibition. However, New York's convention center is now too small to host Pittcon. Smith also said that Pittcon would consider sites in the western United States, such as Las Vegas, which has sufficient convention room space but is booked well into the future. In the meantime, Pittcon will follow an old model of staging the meeting in one city. The convention will be fixed in New Orleans for the years 1998 and 2000 through 2002. "Having it in one ciiy makes it easier on our volunteers," says Smith.
Analytical Chemistry News & Features, May 1, 1997 285 A
