NEW CHEMICALS
LECO
New Source for High-Purity Oxides
N O W 160 L / M — W A S 140 L / M W e l c h Duo-Seal N o . 1402B 1x1CHTORR
A new line of high-purity oxide pow ders is available in particle sizes of —325 mesh (44 microns or less) and in purities from 99.5 up to 99.995%. Ap plications include a variety of research and development studies on the physics and electronic applications of ceramic bodies. Ceramic Products Division, Materials Research Corp., Orangeburg, Ν. Υ. 10962 503
Ultrapure Organic Reagents
NowjlLWelch Duo-Seaf vacuum pumps have increased capacities. 33 years of vacuum p u m p design and manufacturing technology now enables Welch to sizably increase t h e capacity of all twostage Duo-Seal p u m p s . Size and appearance r e m a i n s t h e same,but p u m p i n g speeds are increased u p t o 19fc over previous models. In 1933, W e l c h pioneered t h e i n t e r n a l v a n e design of mechan ical vacuum p u m p s , long since proved to be t h e most efficient, vibration-free, quiet, long lasting, trouble-free vacuum p u m p s ever m a r k e t e d . A l t h o u g h many other manufacturers have switched to t h e internal vane design, only W e l c h produces Duo-Seal pumps, t h e p u m p s with t h e p a t e n t e d DuoSeal gas discharge design, which eliminates r e p u m p i n g gases. Now, every two-stage Duo-Seal p u m p gives t h e added bonus of increased capacity, increases of u p to Ιθ'/ο, depending on t h e model which fits your needs. If you use vacuum, check on t h e Duo-Seal line. Welch m a i n t a i n s a staff of vacuum specialists who are a t your service t o help you s e l e c t the right pump for your needs. W r i t e T h e W e l c h Scientific Company, 7300 N . Linder Ave., S k o k i e , I l l i n o i s 60076 o r call 312/677-0600.
WELCH SCIENTIFIC
Circle No. 81 on Readers' Service Card 118 A
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ANALYTICAL CHEMISTRY
Intwh*" ...THE 2-MINUTE NITROGEN DETERMINATOR!
Twelve organic reagents which have purities of 99.999% as determined by mass spectrometry and gas chroma tography are being offered for use as reference standards and for precise chemical measurements. The reagents are: acetanilido, anthracene, benzoic acid, benzophenone, biphenyl, d-camphor, dimethyl terephthalate, naphtha lene, phenanthrene, pyrene, t-stilbene, p-tcrplienyl. Packaged under argon gas in leak-proof \-ials, this line of products is available in 5-gram units. Materials Research Corp., Orangeburg, Ν. Υ. 10962 504
Model 738-100 (60-C.) Model 638-100 (50-C.)
Mass Spectrometry Kit A kit containing highly fluorinated organic compounds for use as standards in the mass range up to 1500 in mass spectrometry is available. It includes four pcrfluoroalkyl triazines as stan dards having molecular weights up to 1185 which provide simple intense spec tra in the high molecular weight region. The Mass Spec Kit also contains the four more commonly used fluoroearbon standa rds : perfluorobutylfuran-FC75, permiorobutvlamme-FC43, and both high and low boiling perfiuorokerosene. Peninsular ChemResearch, Inc., Calgon Corp., P. O. Box 14318, Gainesville, Fla. 32601 505
Thiocarbamyl-Nitro-TB Commercially available for the first time, Thiocarbamyl-Nitro-TB is used as a histochemical and cytochemical reagent for the detection or determina tion of dehydrogenase system, NAD, and for electron microscope studies. It is available as a yellow, crystalline pow der in 250 mg and 1 gram amounts. Mann Research Laboratories, 136 Lib erty St., New York, Ν. Υ. 10006 506
The LECO TN-14 Direct Read ing Nitrogen Determinator ac curately determines nitrogen in most metals . . . including silicon steels in less t h a n two minutes. Eliminating the problems as sociated with most vacuum fusions or Kjeldahl methods, this compact, lightweight unit is fast, accurate and automatic. A unique impulse furnace heats a single-use graphite crucible to approximately 2800°C in less t h a n 15 sec onds. The nitrogen released at t h e s e h i g h t e m p e r a t u r e s is analyzed by thermal conduc tivity and results a r e read di rectly from a digital display.
LECO
LABORATORY EQUIPMENT CORPORATION
1415 Hilltop Road St. Joseph, Michigan 49085, U.S.A. Circle No. 130 on Readers' Service Card
