New
Products
SEM The DSM 982 Gemini scanning elec tron microscope is designed to pro vide high resolution at low beam en ergies for surface imaging and analysis in materials science and bio logical applications. The microscope has guaranteed resolution as low as 1 nm at 30 keV electron beam energy and 4 nm at 1 keV. To achieve high resolution at low beam energy, the electron optical column design includes a beam booster system and an objective lens that combines electrostatic and elec tromagnetic lenses. The design mini mizes the required electron beam diameter and stabilizes high beam currents. The microscope uses a Schottky field emission gun source and a secondary electron detector. The DSM 982 Gemini contains a large sample chamber with a motor ized stage that accommodates sam-
INSTRUMENTATION Low-temperature FT-IR An upgrade for the Model 2000-A MultiMode FT-IR system extends the operating temperature range for transmission, spec ular reflectance, and large-angle reflec tance IR spectroscopy down to -170 °C. The system now operates at temperatures ranging from -170 °C to 900 °C and at pressures from high vacuum to 2000 psi for all spectroscopic modes. Applications for the system include studies of surface coatings, polymers, and solid-gas reac
tions. Aabspec • 401 Laser diffraction LS200 Series automated laser diffraction particle size analyzer has a dynamic size distribution range of 0.04 pm-2 mm. The analyzer measures the entire range in a single run without the need for changing optics or instrument settings, and data can be acquired from up to 116 size channels. Options include a dry powder module, a 434 A
pies up to 150 mm in diameter and can be tilted up to 50°. Typical analyt ical working distances of < 10 mm with a detection angle of 35° are pos sible. The microscope, which is con trolled by a multiprocessor computer system with an interactive user inter face for instrument setup and image processing, contains 4 MB of inte grated image storage with a maxi mum resolution of 2048 χ 2048
pixels. Zeiss • 402
hazardous fluids module for low-flashpoint solvents, and a microvolume module that accommodates samples of 1-50 mg and uses diluent volumes of 12 mL. Coulter
• 403
contains a 6-L batch extractor vessel that can be configured for either up- or down-flow separations. The system also includes two separation vessels. One separates gas from larger and less soluble molecules in the solute; the other separates lighter molecules and decontaminates the gas. Options for the PDU include a magnetic drive mixer module for continuous extrac tion of liquids, a countercurrent col umn for processes such as the deacidification of fatty oils, and a solvent modifier addition system for process methods development. Pressure
Products • 405 ESR and EPR spectrometry Portable ESR/EPR spectrometer Model 8400 incorporates a compact electromag net and performs autotuning of field pa rameters. The spectrometer, designed for field applications such as dosimetry and process control, can also be used for the detection of free-radical intermediates in semiconductors and radiation damage studies in living tissues and organic mate rials. A dedicated software package pro vides data manipulation and mathematical modeling functions and outputs results to a digital plotter. Micro-Now • 406
Thermal analysis
The HP 7686 PrepStation automatically dispenses, dilutes, heats, and evaporates samples prior to HPLC, GC, or MS analy sis. The optional SPE module performs extractions and filtrations, and both the basic and SPE systems include a barcode reader and Windows-based operating soft ware. The system can be integrated with the 1050 series of HPLC autosamplers or the 5890 Series II gas chromatograph, or used as a stand-alone system. Hewlett
The PL-STA simultaneous thermal ana lyzer performs thermogravimetric and quantitative heat flux differential scanning calorimetry on a single sample. The ana lyzer operates in the temperature range of -125-1640 °C. The combination of tech niques can be used for the interpretation of complex reactions or applications in which a secondary reaction takes place. The PL-STA has a low swept volume for enhanced sensitivity in evolved gas analy sis and can be used for hyphenated tech niques with MS and FT-IR spectrometry.
Packard • 404
Polymer Laboratories • 407
Sample preparation
Process-scale SFE
Protein crystallization
Process development unit (PDU) for SFE is designed to operate at pres sures of 450-700 bar and temperatures of 50-110 °C with a maximum flow rate of 1.5 kg/min at 700 bar. The PDU
The Robotic Protein Crystallization Sys tem II prepares protein crystals by the hanging-drop and sitting-drop techniques. A liquid-level sensor determines the sur face level of the protein solution, and up to
Analytical Chemistry, Vol. 66, No. 7, April 1, 1994
