New Products
GOW- MAC the T.C. 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 corrosion, 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
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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
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918 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 11, SEPTEMBER 1977
Spectrum Analyzer Model FFT 512/S-20 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 spectrum/ 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 powder, 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
