New Products
Pollution/Gas Analyzer The instrument uses a unique mass spectrometer principle that affords p p m range sensitivity, gas selectivity, ruggedness, and ease of maintenance. The system can continuously monitor any number of preselected gases for quantitative measurements including carbon monoxide, sulfur dioxide, and basic hydrocarbons in room or outside atmospheric environments. An alarm unit may also be purchased with the unit to alert an operator that any particular gas level is unacceptably high. Oscilloscope presentation is optional. CVC Products, Inc. 413
SP8000 high-performance liquid chromatograph contains a powerful microprocessor that both monitors operation of the LC components and provides users with the ability to preprogram series of different chromatographic tasks. The SP8000 incorporates a unique ternary gradient system that independently controls three solvents for both isocratic and gradient work. Other advances include a single pump providing pulse-free, constant flow, and a self-contained helium degas system that is easy to use and allows uninterrupted chromatographic operation. Other features include full alphanumeric keyboard with LED display, printer /plotter, temperature-controlled column compartment, automatic sample injector, multiple-wavelength absorbance detector, and dual-channel data system. Spectra-Physics, Inc. 402
Trace I and Trace II spectrophotometer systems are based on the Model 34 UV/VIS spectrophotometer with final answer computer, printer, and special accessories for automatic calculation of clinical chemistries based on kinetic and end-point analyses of enzymes. Trace I and II simplify STAT and routine chemistries and enzyme immunoassays of analyses such as drugs of abuse and anticonvulsant drugs. Results are computed, displayed, and printed out in absorbance, rate, or concentration, as selected. The Trace I system consists of the Model 34 UV/VIS spectrophotometer with heated "sipper" (low-volume heated flow cell), the DP-3000 microprocessor/computer, and a pipetor/diluter. The DP-3000 is preprogrammed to handle 13 standard chemistries and has 25 additional user-programmable chemistries. The Trace II system is comprised of the Model 34C UV/VIS spectrophotometer, which includes a heated "sipper" and a compatible printer. It is specifically designed to perform virtually all clinical chemistry analyses and features a substrate depletion warning. Beckman Instruments, Inc. 401
Gas Chromatograph/ Mass Spectrometer HP 59993A fully integrated GC/MS incorporates all-digital electronics, a m i croprocessor-controlled GC, electron ionization source, hyperbolic quadrupole mass filter, electron multiplier detector, power supply, analyzer vacuum system, inlet vacuum system, and a GC/MS membrane interface. The data system includes an HP 21 MX E-Series microprogrammable 16-bit computer with 32K words of memory and an HP 7900A dual-disc drive with 5 megabytes of data storage. Ions are detected by the continuous dynode electron-multiplier detector. Sensitivity is rated at 10 to 1 on 1 ng of methyl stéarate, scanned at 300 a m u / s . The mass range is 1 0 - 8 0 0 amu. Optional features include a jet or membrane separator; a capillary injection system that operates in the splitless mode; Aldermaston, EPA/NIH, and contributed spectral l i braries; and a data communications interface to allow transmission between the GC/MS and the Cornell or Cyphernetics timeshare systems. Basic syst e m , excluding the CRT terminal, is priced at $70 000. Hewlett-Packard Co. 415
For more information on listed items, circle the appropriate n u m b e r s on one of our Readers' Service Cards
910 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 11, SEPTEMBER 1977
Model D-400 amino acid analyzer separates and measures amino acids in protein hydrolyzates and biological fluids by single-column, high-resolution ion-exchange chromatography. As many as 24 samples can be injected. The narrow diameter column increases the sensitivity of analysis to 0.5 nm each component and reduces the consumption of reagent and buffers. An integral ammonia filter continuously removes contaminating amines from all buffers. Linear absorbance detection of ninhydrin-positive components in the sample is displayed on a two-pen continuous writing recorder. Chromatographic procedures are time directed by a 15-channel programmer that can select six buffers and two column temperatures plus control accessories including an optional calculating integrator. Durrum Instrument Corp. 407
New Products NMR Spectrometer Model PMX60 proton NMR spectrome ter is a high-performance (30:1 S/N on 1 % EB), permanent-magnet system and features the latest in solid state cir cuitry. It features a color-coded key board to simplify operation. Optimum parameters can be selected automati cally, or specific conditions can be se lected. A visual meter for tuning resolu tion also allows observation of lock and signal intensity. A hold button facilitates simple integration control and can be used to eliminate unwanted solvent or water peaks from the spectra. Internal lock and homo nuclear decoupling is built into the console. A compressed air device simplifies sample tube inser tion and removal as well as minimizes abrupt temperature changes within the magnet console during sample tube ex change. Jeol Analytical Instruments
410
Colored Glass Filters Seventy-eight individual 50-mm square colored glass filters are supplied with individual spectrophotometer curves. Surface parallelism and finish are held to high standards. Each filter is marked with an identifying portion of the cata log number for permanent recognition. Available in protective plastic display pages that can be incorporated into a storage binder. Melles Groit 420
SpectrEL Simuiscan 200 GC/MS offers simultaneous analysis by chemical ionization and electron impact ionization methods in one instrument. In addition to time savings and conve nience, this simultaneous scanning provides the certainty that the CI and El spectra come from the exact same sample. The two spectra can be obtained at scan rates of 2 ms/amu. The Simuiscan systems are available with either the Varian or HP Series GC's or can incorporate the GC best suited to the customer's individual needs. The standard system includes positive ion mass spectrometry, analog detection, and operates to mass 1000. Options available include the addition of negative ion mass spectrometry, pulse counting detection, and a mass range to 1200 amu. Extranuclear Laboratories, Inc. 404
For more information on listed items, circle the appropriate numbers on one of our Readers' Service Cards
Dye Lasers The DL-II series of dye lasers includes the DL12 with oscillator, the DL14 with oscillator/amplifier, and the DL14P with oscillator/amplifier with pressurescanned étalon for 0.0006-nm resolution at 460 nm. The range of the DL-II series is 2 1 7 - 9 3 0 nm when nitrogen laser pumped, and 3 2 4 - 9 3 0 n m when Nd.YAG pumped. Synchronized frequency doubling is achieved with a new desk calculator accessory that permits selection of scanning either linear in wavelength or wavenumber as well as data acquisition. Similarly, the wavelength range to be scanned and the ordinate expansion may be simply programmed to suit specific requirements. Price of the DL12 is $7950, the DL14 is $9250, and the DL14P is $9750. Molectron Corp. 411
Liquid Chromatography System
The PW 1410/20 ΑΗΡ x-ray spectrometer/desk calculator system offers users an automatic machine producing fast results at a moderate price. The spectometer incorporates a micro processor that can accept and store a large number of analytical programs. The operator simply loads the sample and selects the desired program via the calculator keyboard. Analysis is performed entirely automatically, and the calculator, an HP 9814A, converts the received in tensities into element concentrations, which it then prints out. It is ideal for both production-line quality control and laboratory research application. Philips Industries, Scientific and Analytical Equipment Dept., Lelyweg 1, Almelo, The Netherlands 405 912 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 11, SEPTEMBER 1977
This " b e n c h - t o p " system for low-pressure applications contains a Mixograd gradient former, Minipuls peristaltic pump, chromatographic spectrophotometer, column, valve, fittings, shut-off valve, and Race Track fractionator. Components can be substituted or eliminated to meet particular applications— ion exchange, gel permeation, absorption, HPLC, etc. Gilson Medical Electronics 417
New Products
Algorithms for Chemical Computations ACS Symposium Series No. 4 6 Ralph E. Christoffersen, Editor The University of Kansas A symposium sponsored by the Division of Computers in Chemistry of the American Chemical Society. This multidisciplinary collection of state-of-the-art papers assesses significant developments in algorithms for several important areas of chemistry and pinpoints places where currently available algorithms are inadequate. Leading experts not only evaluate the |tremendous opportunities for progress in chemical research that algorithms provide but also analyze the substantial difficulties that algorithms may present. Topics covered include those of particular interest to scientists doing 'significant amounts of computing in Ithe fields of quantum chemistry. Iscattering, computer handling of " :hemical information, and solid state heory. CONTENTS Graph Algorithms in Chemical Computation · Algorithm Design in Computational Quantum Chemistry · Rational Selection of Algorithms for| Molecular Scattering Calculations · Molecular Dynamics and Transition State Theory · Newer1 Computing Techniques for Molecular Structure Studies by X-ray Crystallography · Algorithms in the Computer Handling of Chemical Information
Model SF-330 spectrofluorometer, designed for operational simplicity and user convenience, is intended for food processing, drug manufacturing, biological, and chemical laboratory applications that require a moderately priced sensitive instrument for analysis of trace concentrations of organic and inorganic chemicals. Features include two photomultiplier detectors, a 150-W xenon lamp source, two concave grating monochromators, selectable spectral bandwidth combinations, scan speeds of 25 or 50 nm/min, and digital readout. $5795. Varian Instrument Div. 406
Dual-Wavelength Detector System D-137 is designed to be added to the Durrum-Gibson stopped-flow mixing chamber. It employs split-beam dual-detection optics to measure fast reactions at t w o wavelengths simultaneously. The t w o signals are then processed by solid state electronics to provide the ratio and difference of the t w o signals. By selecting appropriate wavelengths, small absorbance changes of fast reactions can be measured in turbid solutions where single-wavelength measurements are hampered by effects of scattered light. Durrum Instrument Corp. 418
151 p a g e s ( 1 9 7 7 ) C l o t h b o u n d $ 1 2 . 7 5 L C 7 7 - 5 0 3 0 ISBN 0 - 8 4 1 2 - 0 3 7 1 - 7 SIS/American· Chemical Society 1155 16th St., N.W./Wash., DC. 20036 Please send copies of SS 46 Algorithms for Chemical Computations at $12.75 per copy D Check enclosed for $ . • Bill me. Postpaid in U.S. and Canada, plus 40 cents elsewhere. Name Address City
Slate
Zip
Carbon Analyzers These carbon analyzers use a new c o u lometric carbon dioxide titrator t o provide high accuracy in a wide variety of carbon analyses including mineral carbon, total carbon, and organic carbon in water, oils, and solids. Carbon levels from sub ppm t o 1 0 0 % can be determined. The coulometer can also be used for other high-accuracy CO2 measuring applications. Coulometrics Inc. 419
914 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 11, SEPTEMBER 1977
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An interface to combine liquid chromatograph and mass spectrometer systems permits mass spectral analysis of those chemicals difficult to identify with a GC/MS. Among its features, the interface allows free choice of electron impact or chemical ionization and does not interfere with GC/MS or solid probe operation. It provides high sensitivity LC detection, high sample yield, and high chromatographic integrity. It is particularly useful in mass spectral analysis of mycotoxins, polycylic aromatic compounds, pesticides, steroids, triglycerides, coumarins, and many drug metabolites, and will have wide applications in pharmaceutical and biomedical research, and in petroleum, energy, pollution, and pesticide studies. The interface can be added to any Finnigan mass spectrometer with a differential pumping system. It can be installed on a new mass spectrometer or retrofitted to an existing system. Finnigan Corp. 403
New Products
The most intelligent microbalance
The new AD-2Z Autobalance with both Autoranging and Autozero It can set zero, balance the beam, select the best range, shift the decimal, display the weight on a large digital readout, print it (with an optional printer) and much more . . . all automatically and within seconds. That's what all microbalances should do, but only the AD-2Z does. 5 gram capacity, 0.1 microgram sensitivity. Recording and vacuum models available. Call your local Perkin-Elmer sales office, or write Instrument Division, Perkin-Elmer Corporation, Main Av enue, Norwalk, CT 06856.
PERKIN ELMER CIRCLE 168 ON READER SERVICE CARD
For Liquid Chromatography
VALCOS MULTI LOOP AUTO SAMPLER . . . the automatic sample injection system that lets you Minimize Sample Waste, Maximize System Efficiency
All for under $3,000. • Ideal for low waste applications where very little sample is available • Small uniform bore minimizes error due to sample carry-over • Improves repeatability of recorded area and retention times • Up to 150° continuous operation in high temperature GPC (optional) • No pressurized gas required for sample loading into injection valve • No bottles to fill, break, or lose
• All Hastalloy C and nickel flow path avail able for reactive samples (optional) • BCD samples number identification for use with computers or integrators • Pulse and continuous contact closures available • Up to 4 injections per sample • Simplicity of operation instruments co
VALCO
Ρ Ο Box 19032 HouslOti I» 77024 713-6S8-9345 TWX:etO-881-5500 Telex 79-0033
CIRCLE 223 ON READER SERVICE CARD 916 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 1 1 , SEPTEMBER
1977
UV-VIS Spectrophotometer Model 576 scattered transmission spectrophotometer is designed specifi cally to handle turbid, scattering sam ples. Automatic digital background cor rection compensates for initial differ ences between cells. The background corrector automatically plots out the flattened spectrum, and necessary cor rections are stored in digital memory. A modified sample can then be run, and the difference spectrum superimposed. Repetitive scanning capability is also a standard feature. Data can be either su perimposed or presented sequentially on the instrument's Format recorder. The instrument sample compartment can accommodate all of the sampling accessories developed for the 57 Se ries. Perkin-Elmer Corp. 412
Preparative Gel Electrophoresis The vertical column system accepts sample loads up to 5 times greater than those accepted by existing systems and can easily handle up to 20 times that amount when fitted with a larger option al inner column. Recovery rate typically exceeds 8 0 % , and the design minimiz es eluate dilution. No pumps or cooling systems are needed. The cylindrical de sign eliminates leakage and consequent sample loss and makes the cell easy to use and clean. Camag Inc. 416
Differential Corrected Spectra Unit The differential corrected spectra unit, a digital microprocessor system de signed for use with the Model MPF-44A fluorescence spectrophotometer, can store in memory all of the correction factors needed to correct excitation of emission spectra. This is an electronic feature equivalent to the optical func tion of a double-beam spectrophotome ter. Applications include detection of small differences in samples for c o m pound identification in quality control, elimination of fluorescing solvents or blanks, screening unknowns, elimina tion of Raman bands, and storage of original spectra of unstable samples. Another mode of operation of the unit provides a combined excitation emis sion scan of a sample of interest. Per kin-Elmer Corp. 421
For more information on listed items, circle the appropriate n u m b e r s on one of our Readers' Service Cards
New Products
GOW-MAC the XC. Detector Specialists can keep your GC in business. The best way to save money is preventive care of your T.C. detector. A cell using hot wire filaments operates at elevated temperatures, the wires, too, are hot due to the current passed through them, therefore subject to oxidation. Many things can oxidize the detector elements: samples, leaks, inadequate purge. When filaments are oxidized their resistance will change and the bridge is out of balance. Certain filaments resist oxidation more than others under different conditions. Other things which unbalance bridge circuits are ccrrosion, vibration, column bleed, carbon deposits, etc. GOW-MAC can help by the availability of numerous filament materials and years of experience in solving such problems. Thermistors are also available in various resistance ranges. GOW-MAC can supply detector elements for most of the gas chromatographs in production as well as those that are no longer manufactured.
Four ways to solve the problem and save time and money: 1. Purchase detector elements in pairs. If you have several T.C. instruments and want to re-filament your own detector this is fast and the least expensive approach. You can have elements in stock or, we can ship from stock. Even our representatives have emergency stock for customers in trouble. 2. Purchase a quad, (four matched elements). This is for those who have one or two units and want to refilament the cell themselves. With a quad, anyone can re-filament his own detector. All four elements are
GOW
matched so you don't have to pick two matched pairs to make a wellbalanced bridge. 3. The easiest, not the quickest or least expensive, is to take the cell block out of the detector oven and send it to us. We will clean, refilament, check for leaks, drift and noise for $110.00*. This takes at least 48 hours, so allow one week for us to receive and return. 4 . You can also purchase a spare detector and keep it on the shelf. Most detectors can be supplied by GOW-MAC for about $150.00. Take your pick, by ordering directly from GOW-MAC you can save either money, time, or both.
We're prepared to send time and money saving information: 1. Filament Bulletin listing 8 different materials available for detector elements including thermistors. 2. Cell Bulletin which lists 12 T.C. detectors from process to micro, 4 types of Gas Density Detectors. 3. Our Filament Replacement Chart. This lists all major GC manufacturers, instrument models and the GOW-MAC replacement elements. 4 . General Service Bulletin—tells how to re-filament a cell, discusses maintenance and trouble shooting as well as recommended operating conditions for T.C. cells. 5. Price List—this will save you money. We'll even throw in the booklet, "Selecting a GC Column" written for GOW-MAC by Dr. H. McNair. DON'T WAIT! *W or WX filaments for most detectors.
GOW-MAC INSTRUMENT CO. 100 Kings Road, Madison, N.J 07940 Telephone: 201/377-3450 Telex: 136331 Shannon Free Airport, Co. Clare, Ireland CIRCLE 80 ON READER SERVICE CARD
MAC
918 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 11, SEPTEMBER 1977
Spectrum Analyzer Model FFT 5 1 2 / S - 2 0 spectrum analyzer incorporates an all-digital range translator that enables the analyzer to magnify the resolution in any selected region of a spectrum by factors of 8, 16, 32, 64, or 128. If the magnified portion is of much lower amplitude than parts of the original spectrum, additional gain of X 2 , X 4 , and X 8 is provided. With this feature, resolution to within 2 Hz is provided in the 0 - 1 0 0 kHz range, and within 0.4 mHz in the 0 - 2 0 Hz range. Additional features include vertical scale calibration in arbitrary engineering units over wide ranges, and display on c o m mand of the ratio: active s p e c t r u m / stored spectrum. Rockland Systems Corp. 414
Chemicals Ethyl Fluorescein Kromex fluorescein, ethyl ester, is a fluorescent agent potentially useful in biomedical and biochemical research studies where fluorescein has proved valuable. This high-purity compound has a quantum yield of greater than 0.95 and is believed to have greater membrane permeability. It is characterized by a broad-based actual lot analysis, and a certificate of the analysis is supplied. Available in 2-g size. J. T. Baker Chemical Co. 424
Immobilized Proteolytic Enzymes Sorbazyme-Q series of immobilized e n zymes consists of a variety of proteolytic enzymes attached to an inert matrix of cellulose with retention of catalytic properties and improved stability. They are supplied as a white, dry p o w der, can be recovered at the end of a reaction and reused many times, and can be packed in columns and used in a continuous flow reactor. Quantimetrix Medical Industries 425
Ultrapure Elements Antimony, arsenic, bismuth, cadmium, copper, gold, indium, lead, selenium, silver, sulfur, tellurium, thallium, and zinc are offered at 9 9 . 9 9 9 + % purity. Quantities available range from hundreds of grams to kilograms and are available in various bulk forms including shot, rods, and fragments. Each shipment includes information on impurities, toxicity, and handling. Reactor Experiments, Inc. 426
