The CDS 330 GC Sample Concentrator The value is in the versatility. Economical yet powerful automated concentrator brings you these capabilities: • Purge & Trap of Liquids & Slurries • Thermal Desorption of Solids and Air Sampling Cartridges • Controlled Atmosphere Thermal Processing • Ambient or Cryogenic Trapping • On Column Cryogenic Focusing • Glass Lining Available Write or call for free literature.
CDS
Chemical Data Systems AE/CDS Autoclave Inc. «7000 Limestone Rd., Oxford, PA 19363·Phone (215) 932-3636 CIRCLE 30 ON READER SERVICE CARD
Not just a Particle Sizer AUTOSIZER IIc-SYSTEM 4700c-ZETASIZER He-all offer the best in submicron particle characterization. But that's not all. Because they share the same advanced correlator and computer, simply by adding one of the other optical units you can have fast, reliable and easy to use submicron particle sizing, a full research light scattering facility which includes absolute MW measurements via Zimm plot analysis or electrophoretic determination of zeta potential. All at minimum cost. Nowhere else can you get such a powerful combination for studying, particle dynamics, polymer properties and interfacial phenomena in colloidal systems. Malvern designs more into its products so you get more out of them.
Malvern Instruments Inc., 200 Turnpike Road, Southborough, MA 01772. Tel: (617)480 0200 Telex: 311397
MALVERN
CIRCLE 95 ON READER SERVICE CARD 772 A · ANALYTICAL CHEMISTRY, VOL. 59, NO. 11, JUNE 1, 1987
FOCUS area and flash vaporize, and then into an electron beam where ions are generated by EI [electron ionization]." The patent for the MAGIC interface is held by Georgia Tech, and H P is the owner of an exclusive license for its development. According to Browner, "Hewlett-Packard is exploring its commercial potential." The difference between the MAGIC interface and Extrel's ThermaBeam appears to lie primarily in the way the aerosol is generated. However, Extrel's recent patent filing on ThermaBeam is a reflection of the company's contention that the interface is sufficiently different from the MAGIC interface to warrant patent protection. "I think the real interesting part will be in seeing how the instrument companies fight it out with patents," comments Jack Henion, "because H P is also interested in the MAGIC type of interface. So it may be a case of companies stepping on each other's toes. Extrel claims that the ThermaBeam interface is really not MAGIC, and technically it isn't, but there appears to be a very subtle difference in the way the interfaces work. Unfortunately, these patent problems can delay progress for the customer." "But the important thing," Henion continues, "is that two companies, HP and Extrel, are sticking their necks out and doing something that I feel very strongly about, and that is the need to obtain EI information from LC/MS. All direct liquid introduction-type LC/ MS interfaces, including thermospray, provide Cl-type information, with little or no structural information. Everyone who's accustomed to doing MS likes to have EI data to interpret spectra, to carry out mass spectral library searches, and to really characterize compounds rather than just look for molecular weights. That is important, and it's been overlooked, I think, as we've all searched for some ideal way to do LC/MS. But I think it's significant that two manufacturers are putting R&D money, time, and people onto a project to try to do LC/MS and get EI. I'm glad to see it and I welcome it. I'm not sure that either of them have the right answer, but I think that you make progress by trying something rather than just sitting around criticizing what others are doing, and I commend them both for doing that." "The real exciting potential for the MAGIC type of interface is that it is very adaptable to bench-top mass spectrometers," adds Browner. "It's quite conceivable that we will be able to develop a MAGIC interface that will interface very readily with bench-top instruments such as MSDs. And that is
