tern," Inficon division manager Stephan DeLuca told C&EN. "The Hapsite uses a patented pumping system, a NEG" (nonevaporable getter); that is, a sorption pump with no moving parts. A complete system, including a ser Stephen C. Stinson vice module for recharging the battery C&EN Northeast News Bureau and pump, costs under $80,000. The he trends in optical spectroscopy at portable GC/MS unit alone is priced un Pittcon '97 this year were ever sim der $50,000. pler construction and operation, plus Viking Instruments also showed what it describes as a portable GC/MS system. a narrowing focus on highly dedicated The SpectraTrak 572 (circle 219) is functions. In more than one booth, exhibi much larger and heavier than Inficon's tors told C&EN that they had "tried to make Hapsite, but it is designed to stand up to it like an ATM.'' In other words, such instru ments are so much like automated teller ma use in the field or in factories. The system is equally as capable in chines that "anyone" can use them. the lab or in the field," said Viking's Ray And one attendee told C&EN that mond J. Matejczyk. "We find our custom when a company introduced a new highers don't need to use the system in the performance liquid chromatograph a field more than about 20% of the time. It while back, sales were modest. But when can be routinely used in the lab and the firm labeled it a catecholamine analyz packed up in five minutes.'' er, sales took off. Similarly, a system origiMatejczyk said that in the wake of the nerve gas attack in the Japanese subway and the Kyoto earthquake, SpectraTrak 572 units are being mounted on Japa nese fire trucks for emergency response. Systems start at $89,000. At the opposite extreme from the com pact mass analyzers that instalment com panies are using in portable and benchtop GC/MS and LC/MS units are the ultra-highresolution Fourier-transform MS (FTMS) systems based on superconducting mag nets. IonSpec showcased at Pittcon '97 its new HiResESI (circle 220), an FTMS sys tem with an external electrospray ioniza tion source that can be coupled to HPLC. The system, equipped with a 4.7-Tesla superconducting magnet, covers a mass/charge range from 100 to 10,000. It can fully resolve molecular weights up to 30,000, company president Richard L. Hunter says. The price for the complete electrospray system is $340,000. Beckman's DU 500 UV-Vis Bruker Daltonics introduced improve spectrophotometer (above); ments to its FTMS instruments with its Spectronic Instrument's APEX II line of products (circle 221), all new (left) and old UV-Vis spectrophotometers supplied with an electrospray ionization source. In addition to 30-, 4.7-, and 7.0Tesla magnets, a high-field 9.4-Tesla nally introduced for capillary shielded magnet option—"the ultimate in electrophoresis succeeded large protein or DNA analysis,'' according only when the maker called it to Laukien—is now available for about a DNA sequencer. $1.5 million. New automation and soft Optical spectroscopic in ware techniques are also being offered. struments identify or measure And Finnigan announced that the amounts of species in samples framework and construction of its New- by detecting emission or ab Star FTMS units have been changed so that sorption of electromagnetic they now can be upgraded in the field radiation. Chemists name the from a 3.0- to a 7.0-Tesla magnet. The new regions of the electromagnet T-Series (circle 222) starts at $500,000.^ ic spectrum arbitrarily, but in
Optical Spectroscopy
T
terms of new instrument offerings at Pitt con, they may be taken as the mid-infrared (mid-IR, 3 to 30 urn, 330 to 3,300 cm'1), near-IR (3 to 0.78 μιη, 3,300 to 12,800 cm"1), ultraviolet-visible (UV-Vis, 190 to 800 nm), and X-ray (0.01 to 10 run). Among general-purpose Fouriertransform infrared (FITR) spectrophotom eters on the exposition floor at Pittcon, Perkin-Elmer introduced the Spectrum 2000 Explorer (circle 223). The company intends this as a bare-bones, affordable, re search-quality instrument that users can add on to. The detector is a thermoelectrically cooled deuterated triglycine sulfate detector, which yields a more constant re sponse than an uncooled detector would, yet is more convenient than liquid nitro gen-cooled mercury cadmium telluride. One configuration with microscope and attenuated total reflection attachment is priced at $83,500. An unrelated new FTIR microscope from Perkin-Elmer sells for $85,000 to $95,000 for a complete system or $60,000 for the microscope only. Called AutoIMAGE (circle 224), the system features complete computer control of aperture, focus, illumi-
MARCH 31, 1997 C&EN 47
instrumentation nation, and movement of sample on the stage by a joystick or mouse. In addition, users can circumscribe a minute area of interest with a square and acquire the IR spectrum from that surface feature only. A more highly dedicated FT near-IR system from Perkin-Elmer is the IdentiCheck (circle 225) at a cost of $28,000 to $55,000, depending on accessories. This instrument is intended for drug, plastics, or food manufacturers to verify identity and purity of liquid or solid products. Accessories include reflectance units to analyze powders and tablets directly in their containers, plusfiber-opticprobes to dip into samples. The $40,000 Infralyzer (circle 225) from Bran+Luebbe also handles inhomogeneous solids, which go into a rotating sample cup so that the machine can average over the whole mass. A covered sample cell that gently compresses powders for more reliable analysis is also available. The Infralyzer has what the company calls an "embedded computer." The user slips 3.5-inch diskettes into a drive to set the analytical method to be used. A variation on FTIR for research or the drug industry is the Chiralir (circle 226) from Bomem. This $90,000 instrument is specifically designed for vibrational circular dichroism (VCD). VCD is a plot of IR frequency (cm-1) versus the differential absorption of left- and rightcircularly polarized light (C&EN, Jan. 16, 1995, page 27). One application is determination of absolute configuration of optically active compounds. Each enantiomer has a VCD spectrum that is the opposite of the other. That is, the distribution of peaks and valleys above and below the ^-axis is equal and opposite. Chemists can calcu-
Perkin-Elmer's FTIR microscope 48
MARCH 31, 1997 C&EN
?
97 late the cApccted VCD spectrum of one enantiomer and compare that with the experimental. A second use is analysis of enantiomeric excess, especially of compounds with more than one chiral center. Yet other determinations are configurations of small-molecule compounds and biological macromolecules in solution. In addition to research and quality control in laboratory settings, IR finds use in process control on-line. For example, ASI Applied Systems exhibited the ProcessIR 4000 (circle 227) process monitor. Measuring only 30 inches wide by 38 inches high and 27 inches deep, the 250-lb, $65,000 unit mounts right next to a pipe in the process. The unit connects to a sensor installed in the pipe. IR light passes into and back out of the flow through a diamond lens. In one sensor type, a sonic generator blasts the diamond surface clean between FTIR samplings. In another type, a pneumatic valve slams shut if a leak develops in the sensor. Sensors operate from -78 to 250 °C and up to 1,500 psig. The analyzer box outside can run at plant temperatures of 0 to 50 °C. Another useful product for process control or development is the new Rov-IR (circle 228) series of FTIR and FT near-IR analyzers for liquid streams from Analect Instruments. Roughly the size of a hip-high chest of drawers, a unit rolls out to the part of the plant where it's needed. In a batch plant, during development of a new process, the analyzer may indicate when starting materials have reacted completely. With continuous processes, the analyzer may be used to troubleshoot, indicating where a permanent FTIR on-line analyzer would best serve. Analect prices the
analyzers at $80,000 to $150,000, depending on configuration and accessories. An analogous FTIR instrument for gases is the I-Series (circle 229) from MIDAC Corp. In addition to process development, users can also check compliance with regulations on emissions. Because the analyzer works in real time, plant operators can use the unit to fine-tune a process. A library of standards lets users identify and quantify compounds. MIDAC was a pioneer in bringing FTIR to use in both industry and battlefield detection of chemical warfare agents. The spectrophotometers feature a monococque construction, in which the instrument case is integral with the optical bench inside. In early years, company President Jerry Auth used to bring a unit to the site of a prospective customer, drop it on a concretefloor,and then show that the unit still worked. Sales and marketing manager Heidi Auth told C&EN at Pittcon that the I Series got another such test when one of the express delivery company's helicopters crashed with one on board. Though the box was crushed and the technical manuals inside shredded, the unit still worked. The Infracal Oil/Grease Analyzer (circle 230) from Wilks, at $4,675, is a more narrowly dedicated instrument. Capable of reading at four wavelengths, units accommodate either a cuvette (rectangular prismatic sample tube) or an IR card. The latter is a product from 3M for preparation of samples as films deposited on the card. Card readers also take reusable sapphire plates from Wilks for the hexane sample extraction method that is coming into use now that the ban on chlorofluorocarbons is forcing the phaseout of extraction with 1,1,2-trichlorotrifluoroethane.
Petkin-Elmer's IdentiCheck FT near-IR system
A second dedicated Wilks analyzer is the Infracal Thickness Gauge (circle 231). Priced at $4,925, the unit uses IR to measure thicknesses of coatings deposited on circles cut from sheet metal. For users who do not want to cut a circle out of a sheet, a bottom-reading version, which costs $5,500, reads the coating thickness after being placed on the metal surface. Although Raman spectrometry uses UV rather than IR light, it is also a form of vibrational spectrometry. A detector placed at right angles to the sample tube analyzes scattered light. Most scattered light is of the same wavelength as the excitation beam. But because of interaction with individual vibrational states within molecules, some scattered light is a discrete number of wave numbers (cm-1) away from the excitation beam. The pattern of differences in wave numbers from the excitation beam is the Raman spectrum. One problem sometimes encountered with Raman spectroscopy is fluorescence triggered by the UV beam. The Raman spectrometer introduced by Nicolet Instalment aims to avoid this problem by using a laser beam at 1,064 nm in the near-IR, a wavelength that does not excite electronic transitions. The $80,000 FT-Raman E.S.P. (which stands for enhanced synchronization protocol, circle 232) comes with a spectral library of 14,000 compounds, including polymers and copolymers. Accessories available at extra cost are a microscope and sample changer. The new Raman process analyzer from Instruments S.A. also avoids sample fluorescence. The usual laser is a green one, but can be changed to a laser at 785 nm if fluorescence is a problem. The Spectraline Process Analyzer (circle 233) needs only 110 volts and 20 amp, and no water, air, or purge gas. Whereas fluorescence is a nuisance in Raman spectrometry, fluorometry is a spectroscopic method in its own right. At Pittcon, Systems & Processes Engineering Corp. introduced the fLF frequency-domain fluorometer for timeresolved fluorescence analyses (circle 234). With this instalment, the user differentiates among fluorescences that occur at the same wavelength. Because the nature of the sources differs, the fluorescences have different lifetimes, from 100 picoseconds to 200 nanoseconds in the case of the operation of the fLF. The $30,000 unit, which measures 8 x 9 x 7 inches, was originally developed to detect biological warfare agents. Indeed, one civilian use is identifying and distin-
MIDAC Corp. 's FTIR gas analyzer (left); ASI Applied System's IR process monitor
guishing bacteria. The excitation light in the unit sets off fluorescences from flavinoid cofactors in bacterial cells. But the fluorescence lifetimes differ according to bacterial species. Measurements take less than four minutes. Beyond bacterial identification, the instalment seems suitable for teasing fluorescences out of any turbid or contaminated sample matrix. Among new UV-Vis offerings were two long-familiar names, the Spectronic 20 and the Beckman DU. Having evolved to independence by turns from Bausch & Lomb and Milton Roy, Spectronic Instruments displayed the Spectronic 20 Genesys (circle 235). Designed for simplicity at $1,475, the unit analyzes from 325 nm to 1,100 nm, with wavelength set by up and down arrow keys. There is a twoline, 20-character liquid-crystal display readout, and the user can print out results as well. The Spectronic Genesys 2PC (circle 236) at $7,200 offers more advanced Windows-based data collection, manipulation, and presentation. The unit features an eight-cell sample holder. Built-in applications include advanced scanning, standard curves, kinetics, absorbance ratio or difference, multiple wavelengths, and performance validation. The Spectronic MiNiMatch (circle 237) is a highly dedicated color measuring device. Priced at $3,500 to $3,950 depending on configuration, the instrument is a dualbeam spectrophotometer with battery-operated portability that a user can run in a
paint store. The MiNiMatch has its own built-in applications software and can also be run from a notebook computer. The DU 520 (circle 238) from Beckman Instruments is a general-purpose instrument priced at $6,000, while the DU 530 (circle 239) at $6,500 is specialized for such biological samples as nucleic acids and proteins. Each interchangeable onecell, multicell, or liquid "sipper" sample holder has a built-in microchip that tells the instrument what kind of holder it is. The Cintra 40 (circle 239) is the latest in the Cintra UV-Vis series from GBC Scientific Equipment. Priced at $14,000 to $18,000, the machine scans from 190 nm to 1,000 nm at a rate of 700 nm per minute. The dual beams have separate monochromators. The company says the Windowsbased software package has a range of most wanted specialized applications. Equitech International introduced its UV-Vis Multiplexed Spectrophotometer (circle 240) at Pittcon. The one spectrophotometer unit can monitor up to 18 fiber-optic probes over a range of 200 to 800 nm with a charge-coupled device (CCD) detector. The price for an instrument with two probes and a computer is $22,900. Company representatives suggest that the unit might serve well in a teaching laboratory, where several students could perform individual experiments hooked to the same instalment. The DR/2010 (circle 241) from Hach is a battery-operated portable UV-Vis designed for water analysis. Priced at MARCH 31, 1997 C&EN 49
instrumentation
y
97
Nicolet Instrument's FT Raman instrument (above); (at left, from top) Thermo Jarrell Ash's direct-current plasma unit; EDAX International's mapping X-ray spectrometer; Micromass' Platform ICP MS instrument
$1,595, the unit allows the user to collect up to 1,000 readings from samples in the field, then download data into a computer in the lab. A printer enables printing out results on-site. The unit analyzes 120 common water quality parameters and comes with preprogrammed methods, many of those approved by the Environmental Protection Agency. Perkin-Elmer also showed its highly specialized, $25,900 HTS 7000 Bioassay Reader (circle 242). The sample holder accommodates microtiter plates in six- or 384-well formats. Thus the instrument can quantitate large numbers of samples or read libraries for combinatorial chemistry. The instalment can be set to read top or bottom of the well luminescence, or through-well absorbance. For example, the analysis of DNA is by absorbance at 260 nm. The TRIAX-190 (circle 243) from Instruments S.A. is an imaging UV-Vis spectrophotometer. Priced at $4,600 with one 50 MARCH 31, 1997 C&EN
grating or $5,300 with three, the unit uses one of several available CCDs for applications such as imaging spectroscopy, characterization of laser diodes or lightemitting displays, and analysis of plasmas. In addition to absorption or reflectance spectroscopy on samples at or near room temperature, chemists can perform absorption or emission spectroscopy on atomized samples generated by flames, arcs, sparks, or plasmas. Flames produce atoms and ions close to ground states, so that chemists can identify and quantitate individual ones according to absorption of light during excitation to upper electronic states. And the ions that occur in plasmas are already in excited states, so that chemists can record characteristic emissions or feed the ions into a mass spectrometer. Varian Associates introduced its rugged single-beam SpectrAA 50 and double-beam SpectrAA 55 systems of atomic absorption (AA) spectrometers (circle 244). Priced at $13,000 to $15,000, each is supposed to be simple to use, highly sensitive, standalone, and low maintenance for teaching laboratories or industrial sites. Because of its simplicity, it is recommended for small colleges. It also resists corrosive, dirty environments such as those in mines, plating shops, and agricultural processing plants. In another offering, Varians SpectrAA220 FS (fast sequential) spectrometer is in-
tended to combine the productivity of an inductively coupled plasma-optical emission spectrometer (ICP-OES) with the low cost of an AA instrument (circle 245). Priced at $24,000 to $30,000, the machine determines 10 elements in sequence in each of 20 samples in less than 50 minutes, compared with more than 130 minutes by conventional AA. Varian has achieved such fast sequential operation by replacing a rotating turret of lamps with fixed multifilament lamps, whose output is selected by a fast, motor-driven mirror. All lamps are lit constantly, pulsed at their right operating currents. And the software package sorts out elements according to the best order for a fast sequence. The company says users can speed things up further by installing Varian's SPS-5 autosampler to prepare standards, dilute samples, add reagents, and perform standard additions. Simplicity of construction and operation also characterize Perkin-Elmer's AAnalyst 100 (circle 246) and AAnalyst 300 (circle 247). The 300 model, priced at $25,000 with computer, is controlled from the computer and does automatic sequential analyses. The 100 model, priced at $14,000 to $17,000, is controlled from a keyboard and is intended for users who do not need sequential multielement determinations. In each model, the six-lamp motorized turret opens from the front for easier user access. The burner assembly is so light that it can be changed with one hand. The user swings the graphite fur-
nace module into place on a hinge rath er than heaving it into place by hand. And the sample compartment is a com modious 11 inches wide and 10 inches deep for easy access. Leeman Labs introduced the Analyte 30 (circle 248) at Pittcon. The $69,500 unit is similar to the company's model 16, but with 30 lamps rather than 16. Like the model 16, the new spectrometer uses atomic sputtering to generate atoms for AA analysis, which the company claims is more accurate, versatile, and productive than methods based on arc/spark, X-ray fluorescence, or combustion methods. The AI 1100/2100 unit from Aurora In struments claims the best of both worlds as a flame or graphite furnace atomizer for AA spectrometry, while a radiofrequency plasma source can be used for emission spectrometry (circle 249). Priced at about $40,000, the AI 1100/2100 has a graphite furnace with a heating rate of 3,800 Κ per second. The JY 2000 family of inductively cou pled plasma generators from Instruments S.A. has been reduced to a small benchtop size and priced at only $75,000 to $82,000 (circle 250). The company says the 40.68-MHz solid-state generator is very stable, with a warm-up time of only 10 minutes. This generator reverses the polarity of the field around the plasma, causing argon ions to collide with argon atoms at high energies, ionizing the at oms and maintaining the superhot plas ma of argon ions and electrons. Thermo Jarrell Ash has reintroduced the direct-current plasma for its IRIS DCP Advantage (circle 251). The instrument industry had gravitated away from direct current, but company representatives say the DCP offers a low-cost alternative to ICP with productivity that is higher than AA. They also say the DCP is better suit ed to such difficult samples as sludges, slurries, oils, and high amounts of dis solved solids. What makes this level of performance possible is the company's CCD detector. An alternative to emission spectroscop ic examination of the sample in a plasma is analyzing the ions in a mass spectrometer. Micromass won the gold award in an informal poll of editors and reporters at Pittcon '97 for its new Platform ICP (circle 252) instrument. Priced at $220,000, the Platform ICP uses a combination of small amounts of helium injected into the argon plus what is called a hexapole ion lens to eliminate argon interferences. In the argon plasma, argon atoms or ions can combine with other atoms or ions to form aggre
gates that look in the mass spectrum like ions of heavier elements. For example, a cluster of argon-40 and carbon-12 can ap pear in the same place as chromium-52. And if two argon-40 species combine, the aggregate can look like selenium-80. The helium-hexapole combination serves to break up such clusters before they reach the mass analyzer. Micromass' /so-PlasmaTrace (circle 253) is dedicated to determinations of isotope ratios for such geological dating methods as rubidium-strontium and ura nium-thorium-lead. The Micromass ap proach to isotope ratios is an array of de tectors for combined high resolution and precision. Prices for the system start at around $600,000. Another high-performance ICP-MS system that debuted in Atlanta is the PlasmaQuad 3 from V.G. Elemental (circle 254). This $170,500 system measures at parts-per-trillion levels, which is impor tant for semiconductors and such highpurity liquids as sulfuric acid used to fab ricate semiconductor devices. Spectro Analytical Instruments claims picogram per liter detectability for the new Spectromass 2000 (circle 255). One feature that ensures such performance is a combination of a rotary pump, a mem brane pump, and two so-called turbomolecular drag pumps. This combination of pumps means that oil lubricating the ro tary pump never gets near the ion optics or quadrupole analyzer. The robustness of the $170,000 to $180,000 system means that it can be run under ordinary laboratory conditions on a daily basis without elaborate disassemblies. In addition to molecular fluorescence from organic samples and atomic fluores cence from inorganic ones, atoms can be made to show X-ray fluorescence (XRF). The X-rays knock electrons out of lowlying K- or L-shells, and the resulting cas cade of electrons to fill the vacancies re sults in characteristic XRF. In the decades of evolution of XRF de tection, the industry has gravitated away from less precise wavelength-dispersive detection (WDXRF)—in which XRF was characterized by wavelength—to energydispersive (EDXRF) detection. Improve ments and lower costs for computer pow er made the switch possible. But now some new instruments have reappeared with wavelength-dispersive detection, based on the capability to analyze for ele ments of very low atomic number. Oxford Instruments has taken a multidispersive approach in the MDX1000 (circle 256). Users can choose either
WDXRF or EDXRF. The instrument is available in a "stripped down" version for $65,000, and the price climbs to $200,000 as more is added on. The wide dynamic range means that users can de termine amounts from parts per million up to levels where the analyte is a con siderable percentage of the sample. Philips Electronic Instruments has chosen an array of four different EDXRF detector types, which, as company spokesmen put it, "brings increased sen sitivity for elements from beryllium to uranium and beyond." The new PW2404 (circle 257) displayed at Pittcon, priced at $225,000, features a one-hour installa tion. Philips arranges in advance for there to be a socket in the wall at the site, and installation is a virtual plug-it-in. A 4-kW generator inside ensures a 33 to 50% reduction in detection time for dif ferent elements in sequence. A 4-kW generator is also at the heart of the RIX 3100 (circle 258) that Rigaku/USA introduced at a price of $180,000. Optical elements called the divergence slit and re ceiving slit can be arranged in three con figurations: standard resolution, high reso lution, and ultralight elements, which be gin at beryllium. Among components of software packages included, one called an order analysis library allows approximate quantitative analysis based on a high-preci sion automatic qualitative analysis, which the library performs without need for stan dard samples. In more highly specialized XRF offer ings, ASOMA Instruments introduced a stream analyzer for monitoring of liquids, slurries, or solutions. The ASOMA Model 500-LLC (circle 259) is priced at $65,000 with single-stream capability, with $6,500 for each additional stream. Up to six ele ments can be detected at a time in each stream, in concentrations from parts per million to 100%, with a typical analysis tak ing 10 to 100 seconds. Two X-ray microscope/mapping sys tems debuted at Pittcon. One was the Thermo Omicron Examinor from Kevex, priced at $165,000 (circle 260). The oth er was the Eagle μ-Probe from EDAX In ternational, priced at $125,000 (circle 261). The Kevex instrument uses propri etary X-ray optics to move about on a sample surface and pinpoint areas 50 μηι in diameter for XRF analysis. EDAX rep resentatives say they can isolate spots less than 100 pm in diameter by moving the microscope stage. Both systems are likely alternatives to costly electron mi croscopes for users who don't need so phisticated mapping capability.^ MARCH 31, 1997 C&EN 51
