MS gas analyzer The MS250 gas analyzer is a compact mass spectrometer designed for use in analytical and process settings for semiconductor, biotechnology, and other applications. It contains a hightransmission 3/4-in. diameter quadrupole mass analyzer to determine components in gases and vapors and can accommodate a variety of sample inlets. The MS250 has a mass range of 1-250 Da and can monitor up to 40 components per stream in 12 s with a survey scan rate of 50 Da/s. Detection limits are 10 ppm using the standard Faraday detector and 10 ppb for noninterfering components using the Faraday detector in combination with an electron multiplier detector. The spectrometer can analyze samples from up to 64 inlets automatically in multistream applications and can be mounted directly onto a low-pressure vessel such as a semiconductor fabrication tool for process monitoring. Inlets with operating temperature ranges of ambient to 175 °C or 100 °C-300 °C are available. The Windows-based operating system provides access to current and archived data in graphic and tabular format. The software controls instrument setup, tuning, data analysis, and calibration and includes user-selectable alarms. Extrel B416
DNA sequencing The Vistra DNA Labstation 625 is an automated workstation that prepares DNA samples for single- or four-dye sequencing methods. It isolates DNA from bacterial cell cultures or phage supernatants, carries out fluorescencelabeling or radiolabeling reactions for sequencing, and prepares samples for loading onto an electrophoresis gel. The workstation consists of a series of built-in functional zones and a control system with autosampler-style pipetting, routing, and temperature control. The workstation zones include a cooling block for sample storage at 4 CC, a 96-well thermocycler for cycle sequencing or constant-temperature reactions, an automated oiloverlay station, a solid-state chilled reagent rack, and a zone for performing fast magnetic separations. Fast magnetic separation replaces centrifugation as a method for isolating DNA from polymerase chain reaction mixtures, bacterial cultures, or phage supernatants. Magnetic particles suspended in a DNA-precipitation cocktail are added to the raw sample in its tube. As the DNA precipitates, it ag-
the use of a PRP-X400 polymeric HPLC column to separate the herbicide glyphosate from water by EPA Method 547. The separation mechanism, column and mobile-phase preparation, and postcolumn derivatization procedures are described and illustrated. Hamilton • 417 Gasoline analysis The first in a series of "Real-Time Systems" application notes for process analytical methods describes the determination of aromatic compounds and various octane numbers in gasolines using the PioNIR 1024 near-IR analyzer. The application note presents a percent aromatics calibration statistics summary and a sample short-wavelength near-IR spectrum. Perkin Elmer B418
gregates and passively entraps the magnetic particles. Activating the magnetic separations rack draws the particles with the aggregated DNA into a pellet for separation from the supernatant. This method can also be used to precipitate fluorescent sequencing products before loading them onto a gel. The graphical user interface, which features command buttons, icons, and windows, displays the workstation layout and provides mouse-controlled setup and method editing. The control system includes > 30 protocols for commonly used sequencing strategies and accommodates user-specified protocols. Molecular Dynamics • 419
CATALOGS Filtration Catalog lists instrumentation and disposables for membrane filtration, microseparation and microconcentration, and preparative and production-scale LC. An applications guide presents product selection tables for membrane filtration products, compatible centrifuges for concentrator tubes, and compatible solvents for the concentrators. Amicon • 420
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Analytical Chemistry, Vol. 67, No. 1, January 1, 1995 57 A
