sample holder, and emission pickup and analysis system. In the excitation system, a xenon lamp provides the light and a monochromator disperses it. The monochromator is motor driven, thus sweeps through its range— 200 to 800 ni/x.—to direct monochromatic light through a slit to the sample. The sample tube is fused quartz, holds 0.5 ml. of material, and is cooled with liquid nitrogen, nitrous oxide, or other refrigerant. The emitted light is dispersed by another monochromator and impinges on a photomultiplier tube which changes it to an electrical signal and amplifies it. From this point, it can be used to drive an oscilloscope or an x-y plotter, depending on the type of study. There are three types of curve the instrument can provide, Aminco says:
EQUIPMENT
PROTOTYPE IN ACTION. American Instrument has put several phosphorimeters into research labs to check out the design. This one is at National Heart Institute
Phosphorimetry Goes Commercial Aminco begins producing instrument to analyze by exciting sample with UV, analyzing emitted light Phosphorescence leaves the mineralogical museum this week, enter's the lists as a commercially available method of analysis. American Instrument, Silver Spring, Md., has begun manufacturing a phosphorimetric analyzer, calls it the Aminco-Keirs Spectrophosphorimeter. The unit works by irradiating a sample with ultraviolet light to excite it, analyzing the emitted light. Phosphorimetry as an analytical technique has been pioneered for many years by Dr. R. J. Keirs of Florida State University. Aminco (which has been making analyzers using fluorescence for many years) has 66
C&EN
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12,
1960
been working with Dr. Keirs, has incorporated many of his ideas into its instrument design. The Spectrophosphorimeter can identify and analyze quantitatively for hundreds of organics ranging from acetophenone to xylene. Included: molecules with multiple bonds which can be made into rigid transparent solutions and are excited by UV. The instrument can also be used for mineral phosphors, which phosphoresce because of the impurities they contain. But, Aminco feels, biggest use will be with organics. How It Works. The Aminco instrument consists of an excitation system,
• Phosphorescence spectra—intensity of phosphorescent emission as a function of emission wave length at a constant excitation wave length. These spectra can be displayed either on the oscilloscope or the plotter. • Excitation spectra—intensity of phosphorescent emission as a function of excitation wavelength. In this case, wavelength of the emitted light is constant. And the data can be displayed either on the oscilloscope or on the plotter. • Decay curves—intensity of phosphorescent emission at a constant wave length as a function of time, after the exciting radiation of a constant wave length has been removed. For fast decay curves (one second or less), the oscilloscope must be used for data display, since the plotter can't keep up. Convert to SPF. The Aminco-Keirs Spectrophosphorimeter will cost about $5600, according to the company. And for only a few hundred more dollars, it can be converted into a dual instrument—handling both phosphorescence and fluorescence. Aminco converts the unit from phosphorescence to fluorescence by removing the cooling flask assembly and sample tube and substituting a fluorescence cell holder compartment. The units will be useful for many types of laboratories, Aminco says. Among them: biomedical research, organic research, perhaps mineralogical research. They can analyze ethylene derivatives, hydrocarbons, amines, nitro compounds, aldehydes and ketones, benzene derivatives, and porphyrins, among others, the company points out. E1 t
Get Sodium Bicarbonate in the grain size you need
every time... FROM CHURCH & DWIGHT
Sodium Bicarbonate U.S.P. Powdered No. 1—For general purpose use in chemical processing, dyestuffs, adhesives, starches, textiles and industrial applications.
Sod ium Bicarbonate U.S.P. Fine Powdered No. 3DF for use specifically in dry powder fire extinguisher mixes, also in rubber and plastics blowing, lubricant for sheet vinyl.
TYPICAL SCREEN ANALYSIS CUMULATIVE PERCENT RETAINED BY
TYPICAL SCREEN ANALYSIS CUMULATIVE PERCENT RETAINED BY
42 Mesh 100 Mesh 170 Mesh
Trace 5% 20.0%
200 Mesh 325 Mesh 400 Mesh
35.0% 70.0% 80.0%
170 Mesh. 200 Mesh.
. Trace .2.0%
325 Mesh 400 Mesh
25.0% 45.0%
Sodium Bicarbonate U.S.P. Granular No. 5 for use in effervescent salts, other pharmaceuticals and special types of cleansers-
Sodium Bicarbonate U.S.P. Treated Free-Flowing for use in fire extinguishers and sponge rubber.
TYPICAL SCREEN ANALYSIS CUMULATIVE PERCENT RETAINED BY
TYPICAL SCR HEN ANALYSIS CUMULATIVE PERCENT RETAINED BY
42 Mesh 65 Mesh 80 Mesh
Trace 27.0% m.5%
100 Mesh. 170 Mesh.
..92.5% ..99.0%
42 Mesh 100 Mesh 170 Mesh.
Trace 5% 20.0%
200 Mesh 325 Mesh 400 Mesh
35.0% 70.0% 80.0%
Are you getting sodium bicarbonate of the specific grain size for optimum results in your process or for m a x i m u m shelf life and performance of your products? You can eliminate doubts by specifying Church & D w i g h t . This simple step will assure you of obtaining t h e widest selection of grain sizes available because Church & D w i g h t is the country's largest supplier of Sodium Bicarbonate U.S.P. You'll also receive for the asking u n m a t c h e d technical service based on more t h a n 100 years of experience with sodium bicarbonate. Unusual grain size requirements are given special a t t e n t i o n . T r y us and see. CHURCH & DWIGHT CO., INC., 70 PINE STREET, NEW YORK 5, N,Y. C&EN
67
NEW
POLARIZING MICROSCOPE by AO The A O Polarstar's building-block concept of design gives you an unequalled choice in the selection of your polarizing microscope and equipment. Various combinations of bodies, stages, analyzers, nosepieces, substage equipment and bases can be selected to provide the exact model you want. Whatever the model, you're assured of top optical and mechanical performance, matchless convenience and versatility... plus these outstanding Polarstar advantages . . . C O A T E D O P T I C S . . . Strain-free Objectives, W i d e F i e l d E y e pieces and a l l essential air-glass surfaces a r e c o a t e d . . . A m e r i c o t e . . . for superior performance.
CONVENIENT CAMERA A C C E S S O R Y . . . Low-cost 3 5 m m camera for use with trinocular or photographic m o n o c u l a r b o d y . S h o o t w h a t y o u see through coupled visual a n d p h o t o g r a p h i c system. Take black and white or full color 35mm photos . . . q u i c k l y . . . easily.
B E R T R A N D LENS . . . Slide-in type . . . b u i l t - i n , focusable . . . for convenient conoscopic observations.
REVERSIBLE B O D I E S . . . I N T E R C H A N G E A B L E . . . Choose from monocular, binocular a n d trinocular bodies . . . a l l inclined for comfort. P O L A R O I D A N A L Y Z E R . . . Choice of rotatable or fixed, swing-in.
C H O I C E O F STAGES ...Plain g r a d u a t e d rotating stage or g r a d u a t e d rotating MicroG l i d e stage for quick convenient specimen positioning.
FOCUSABLE STAGE . . . Y o u focus the stage a n d the specimen to the objective with low, conveniently positioned coarse and fine adjustments. P O L A R O I D POLARIZER . Specially selected fixed Polaroid Polarizer in A b b e condenser permits optimum use of full numerical a p e r t u r e of condenser.Swing-in auxiliary condenser fully illuminates the field of view for orthoscopic work with low-power objectives.
C H O I C E OF BASES...Choose from Built-in Base I l l u m i n a t o r for convenient Kohler type illumination or horseshoe base with mirror.
American Optical W Company *•
*
INSTRUMINT DIVISION, KUFCAIO 19, NIW YORK
Dept. J194 j Write today for 10 page Polarstar Brochure • No. SB 2300! Name. AddressCity
_Zone_
_State_
IN CANADA write—American Optical Company Canada Ltd., Box 40, Terminal A, Toronto, Ontario
68
C&EN
SEPT.
12,
Hard on the heels of Monsanto's introduction of Santofome (C&EN, Aug. 8, page 35), Dyna-Foam Corp., Ellenville, N.Y., has come out with a similar product—expanded extruded polystyrene. Its price: from $3.60 per 1000 sq. ft., a range which allows it to compete with paper for many uses. Dyna-Foam expects its product to find uses in disposable furnishings, food packaging, display and cushioning materials. The company figures that plastics of this nature will create a S500 million a year market; already plastics of various types have replaced 365,000 tons of paper per year. E2
NEW EQUIPMENT Multiwal! bags with a separate, intermediate ply of polyethylene film arc now commercially available from Chase Bag, New York, N.Y. Advantage: Since the polyethylene is not next to the product, it is protected from abrasion and mechanical injury and is thus a more effective moisture barrier, Chase claims. E3 INSTRUMENTS . . .
QUICK-CHANGE NOSEP I E C E . . . C o n v e n i e n t quickchange centerable or triple revolving nosepiece.
SPENCER
Dyna-Foam Offers Expanded Polystyrene As Paper Substitute
1960
New Electrolytic Hygrometer cell, from Beckman Instruments, F u l l e r ton, Calif., is designed to measure moisture contents from 1 to 10 p.p.m. in streams containing more than 50% Ho. The new cell has a shorter electrolytic element than the standard cell. This reduces the error caused by catalytic recombination of oxygen electrolytically generated from the moisture in the stream, the company says. For H 2 contents below 50%, however, the standard cell is suitable, Beckman adds. E4 Inclined-vertical manometers are available from F. W. Dwyer Mfg., Michigan City, Ind. The units are /made in various ranges up to 23 in. of water, are accurate to within 1%, according to the company. E5 Flow switch for bulk materials handling systems responds to lack of material at a critical point. Marketed by Syntron, Homer City, Pa., the device can be used to set off an alarm or to
»
Ε
substitutes the PENICK button for the PANIC button!
O n e of t h e most misguided ideas is t h e concept that "custom manufacturing" is a last resort of production executives in times of hopeless crisis.
given to the ultimate payoff — economical volume production of a uniform, quality product. Late-stage process modifications lose precious time. If the product is a phar maceutical and the process used for clinical materials is part of the NDA, changes are difficult to make.
In fact, "custom manfacturing" so often con notes "emergency", we've coined a new name for our special service. We call it Con fidential Development and Production.
If you anticipate the need for production assistance, call upon Penick as early as pos sible. Your inquiry will be handled at the highest level, in strict confidence, and you'll value the contribution we can make.
Whether in your own plant or in ours, suc cessful processing depends upon early plan ning. From the start, due regard must be
D P
onfidential
C
evelopment
PEEK Product
Development
and
roduction . . . is a unique service encompassing complete laboratory, pilot plant and manufacturing facilities. By cooperative planning early in process development, it assures the most advantageous, eco nomical up-scaling. Particular success has been achieved with antibiotics and other fermentation products, aromatics, botanical derivatives and fine synthetic chemicals.
Department
S . B. P E N I C K & C O M P A N Y 100 CHURCH ST., NEW YORK 8 . 735 W . DIVISION ST., CHICAGO 10
ISïBE i i W
