The 2003 Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy (Pittcon; March 9–14, Orlando, FL) was technically vigorous this year, including many technical sessions relating to the use of lasers in both established and novel scientific areas. Talks were given on developments involving pyrolysis, laser ablation, laser scattering, laser-induced fluorescence, and other instrumental techniques. Specific applications, ranging from the identification of ammunition and coffee beans to novel techniques in cell bioanalysis and trace analysis, were discussed.
Twelve hundred exhibitors presented their wares. Perhaps foreseeing the lower attendance this year, many firms chose to be represented by smaller booths than last year. Nevertheless, even in this off year, many companies announced major new products at Pittcon.
PerkinElmer Instruments (Wellesley, MA) and MDS Sciex (Concord, Ontario, Canada) jointly developed a matrix-assisted laser-desorption-ionization time-of-flight (MALDI-TOF) mass spectrometer (see figure). In MALDI-TOF, pulsed lasers vaporize a sample contained within an absorbing matrix under vacuum conditions. The resultant sample ions are then introduced into the mass spectrometer, which distinguishes the mass of the ions by the time it takes to traverse the flight tube. Measuring the ion masses allows the researcher to reconstruct the identity of the molecules present in the sample. The newly developed system is intended to appeal to the burgeoning proteomics market (see p. 80). It features a novel orthogonal time-of-flight system and makes use of a high-repetition-rate 337-nm-emitting nitrogen laser.
Renishaw (Wotton-under-Edge, England), a major supplier of Raman spectroscopy instrumentation, unveiled two new Raman systems at Pittcon. Raman scattering of monochromatic light results in a small shift in the light frequency that can be used to identify the composition of a sample. Renishaw's structural and chemical-analyzer (SCA) attachment for scanning-electron microscopy (SEM) is a novel method for enhancing electron-microscope images, providing information on the molecular composition of the sample. Renishaw provides several laser options from the visible to the near-infrared, all with micron-scale spot resolution in order to match with the high-quality SEM image. Renishaw also released a new Raman microscope platform with greater capabilities than earlier Raman microscopes. Multiple laser baseplates allow users to switch rapidly between laser sources. As with the SCA, many different lasers are available, from deep ultraviolet to near-infrared.
Like Renishaw, Horiba Instruments (Irvine, CA) has an involvement in Raman spectroscopy through its Jobin Yvon Raman division. Horiba introduced a portable Raman imaging system touted as the world's first portable imaging system with Raman capability. The system uses an on-axis spectrograph connected to an optical-fiber bundle as its probe. The fibers can either be bundled tightly together to provide Raman imaging of surfaces, or split into individual fibers to monitor, for example, multiple pharmaceutical process streams. Horiba Instruments also added a new laser-scattering particle-size distribution analyzer to its line of particle-characterization products. The analyzer can quantify particles in a variety of sample types in the range from 0.02 to 2000 µm. Its 87 detectors improve the resolution and precision of the experimental results over previous offerings. The dual light source consists of a He-Ne laser and a white-light tungsten lamp.
Thermo Haake (Karlsruhe, Germany) introduced a capillary-breakdown extensional rheometer, which uses a laser micrometer to measure the width of a column of viscous fluid as it flows from one circular plate to another. The thinning and breakup of the capillary filament offers information that bears on the extrusion, coating, and fiber-spinning properties of the material.
Michael Tice is a senior consultant at Strategic Directions International (Los Angeles, CA).