CHEMICALS
From grasses six-ch as these gathered in many areas, SRI prepares its standardized fluoride sa_mples of vegetation. Getting representative samples is a major hurdle, requires consultation, between scientists with different backgrounds, such as senior ecologist /\ndre-*w A. Nichol (left), a n d associate chemist Joseph L. Byrne
Fluoride Foilers SRI offers first s t a n d a r d i z e d fluoride samples,· thev're especially for analysts in air pollution w o r k I F you h a v e e-ver delved very deeply into fluoride ainalysis—especially in. the parts-per-zmillioin range—then perhaps you can shudcLer sympathetically with analytical· cheimists f a c e d with the problem. Even for the experienced fluoride analyst there's many a chance for a slip between sample and notebook entry: • Fluorides occur almost literally everywhere, leading to easy contamination. •The basic analytical scheme itself is complex, re-quires almost two days from start to finish. • Samples from different sources may require s-peciaIL treatment that only experience can teach. •Interfering elements are usually present which can lead one astray. All of which has led Stanford Research I n s t i t u t e to offer a n e w service this mori-th-a series of some 35 standardized Suorid-e samples based on common minerals and animal and plant tissues. Occurrence of fluorides in trace amounts was mot a topic of much* discussion mintil tthe early 193(Ts when a remarkalble la^ck of caries i n children in a few commaunities sparked investiga1506
C&EN M A R C H
2 6,
1956
tions that within a few years pointed to fluorides in drinking water. Once the solution was found, interest in trace fluorides quietly waned until 1944 when it revived, this time in connection, with air pollution. Although the veterinarian who noted the first few sick cows didn't have the answer, it was not long in coming—fluoride emissions from industrial plants. • Fluoride Analyses Extensive. Since that time, industry, government, and universities have had numerous programs under w a y on effects and control of fluoride air pollution. And, hand in hand with these has been a continuing need for reliable analyses at the very low concentrations encountered. Today, it is standard procedure for any plant facing a potential fluoride effluent problem to maintain constant checks on vegetation and animals in its vicinity, not only to monitor its effluent control system's operation b u t also to have a continuing factual record available if complaints are received. SRI itself has been involved in one phase or another of air pollution research almost since its founding. Among other projects, it has h a d two field laboratories in operation on fluoride problems since 1949. These, to-
gether with tlae main lab at Menlo Park, Jtiave run. some 80,000 fluoride determinations. S o m e idea of what this m e a n s m a y b e gained from t h e fact that the going price for such fluoride analyses at independent laboratories is in t h e $:25 range—each. With fluoride analyses in the partsper-rnillion r a n g e so easily being incorrect, SRI and its clients have frequently resorted to running replicate analyses individually as cross checks, obviously au expensive procedure. I t was to meet this problem that SRI p r e p a r e d t h e group of standard samples. T h e y are derived from a b r o a d range of minerals, vegetation, and animal tissue commonly found i n industrial fluoride problems—soils, ores, slags, dusts, fertilizers, feeds, hays, p i n e needles, and tree barks, for instance. By slipping i n a standard sample from time to time, an analytical chemist can keep close watch on his techniques m u c h easier than running replicate analyses in cooperation with other labs. S III gathers material for its standardized samples from numerous locations in western, intermountain, a n d southwestern sections of the country. Such a w i d e variety of source materials is n e e d e d since analytical techniques used for individual materials vary in certain details according t o n a t u r e of the material. Source material is t h e n processed b y SRI, and each final sample is packaged in small polyethylene b a g s .
E a c h batch is standardized with analyses b y t w o lab sections. Analytical scheme is basically "the "WQlard and Winter method for fluorides, with modifications inserted at key points as required b y nature of the material. Briefly, the sample is covered with a basic lime solution, evaporated to dryness, a n d ashed. T h e ash is fused with caustic, dissolved in water, and distilled a t 135° C. over perchloric acid. Alizarin red. is added to an aliquot of the distillate, p H adjusted to the acidic side (4.2) and t h e n buffered to 3.2. This solution is then titrated with standardized thorium nitrate. Thorium reacts first with fluoride present, removing it quantitatively from solution. When all fluoride has reacted, thorium
C. E. Kaufman (left), Product Development Manager, Calgon, Inc., discusses the properties of the Pluronics with Ralph Thompson, Research Manager.
"Pluronics offer a combination of properties not available in any other single surfactant" -Ralph N9 Thompson, " W e m a n u f a c t u r e p r o d u c t s for treating water from source to disposal," relates Calgon's Research Manager Ralph N". Thompson. "In our various research activities, we have been, and are now, thoroughly evaluating the Pluronics — W y a n d o t t e ' s u n i q u e series of surface-active agents. "We have established t h a t the Pluronics have a relationship . . . one grade t o another. Consequently, b y evaluating the different grades, we've found t h a t combinations of properties can be obtained with Pluronics which are not obtainable in any other single surfactant by itself. "To date, two of the properties
of the Pluronics have been sufficiently unique to enable us to develop one completely new product, as well as to revitalize and improve one of our present important products." Perhaps your products can be improved using a Pluronic* We at Wyandotte have recently compiled a n e w " P l u r o n i c G r i d , " whereon the property trends of the Pluronics are plotted. By studying these trends, the formulator may select those Pluronic grades with the best balance of properties for his application . . . eliminating random testing, saving valuable research time. This organized approach does not, how-
Research
Manager,
Calgon,
Inc.
ever, eliminate the need for evaluation of the Pluronics in your own laboratories. Write today for samples and your free 'Pluronic Grid." Wyandotte Chemicals Corporation, Wyandotte, Michigan. Offices in principal cities. *REG. U . S . PAT. OFF
Wyandotte CHEMICALS MICHIGAN ALKALI DIVISION HEADQUARTERS
FOR
ALKALIES
Soda Ash · Caustic Soda · Bicarbonate of Soda · Chlorine Muriatic Acid · Calcium Carbonate · Calcium Chloride Glycols · Chlorinated Solvents · Synthetic Detergents Other Organic and Inorganic Chemicals
MARCH
2 6,
1956
C&EN
1507
Another new development using
B. F. Goodrich Chemical
raw materials
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Hycar blankets manufactured by Ha-*zrtz-Aia$onr Inc., VPatertown, Mass. Distributed by JVew England Newspaper Supply Co., Worcester, JWass.
Hycan makes good impression in high-speed printing thousands of n e w s p a p e r s WITH per hour corning off the press, alignment and pressure o n the print ing plate must b e right during the run. That requirement puts Hycar nitrile rubber in the news. Blankets made of rïycar fit around the impression cylinder tbat presses the rolling paper d o w n o n the printing surface. T h e Hycar blanket has to give under the pressure o f the curved printing plate, yet snap back to its original thickness and h o l d it througli millions of impressions. Its thickness can't vary more than a thousandth of an inch.
It takes a special rubber t o take the destructive action of synthetic inks and o i l s used i n today's printing. T h e chemical resistance o f Hycar rubbers is well k n o w n and along with its physical properties i t is the answer to the pressman's problem.
in resistance to oxidation and aging. To find out m o r e about tbese rubbers, please write DeptJEC-2, B.F.Goodrich Chemical Company, Rose Building, Cleveland 1 5, O h i o . Cable address: G o o d c h e m c o . I n Canada: KLitchener, Ontario.
One of the Hycar rubbers can be the answer to your materials requirement. For instance, Hycar polyacrylic rubbers will stand dry heat or oil immersion up t o 35 0° F. Hycar nitrile rubbers are highly resistant t o aqueous solutions including synthetic detergents. Hycar compounds are far superior to general purpose rubbers
B. F . Goodrich C h e m i c a l C o m p a n y
GEON polyvinyl materials « HYCAR American rubber a n d latex · 1508
C&EN
MARCH
2 6, 1 9 5 6
A Division o f The B. F. Goodrich Company
Hycar
GOOD-RITE chemicals and plasfïcizers ·
H A R M O N colors
CHEMICALS forms a pink lake with alizarin, indicat ing the end point. These standards have b e e n used by SRI and a few of its clients for about a year, and n o w they are being m a d e available to industry generally. Sam ples are available with fluoride con centrations of from 5 to 1500 p.p.m., which spans concentrations normally encountered. Once the user reports hack with his results, SRI tells him the accepted value and also whether h e is within the acceptable range, b a s e d on statistical analysis of variations that occur normally. Depending o n magni t u d e a n d direction of a n y error, SRI feels in some instances it may be able to trell users where they h a v e slipped up. Single or multiple samples can be ordered, either on a continuing basis or as a specific problem arises. Cost for the service is $13 per sample.
• Two
silicone
which fabricators
rubber
- The onjy .. ·. truly c o m p a t i b l e , resinous, non-volatile and non-migrating
• Cotton d e f o l i a n t for dust application, Shed-A-Leaf D 5 has b e e n developed by C h i p m a n Chemical. Compound is a white d u s t a n d is applied by either airplane or ground dusters. C o m p a n y says it is nonpoisonous and does n o t corrode e q u i p m e n t . N e w product will b e offered i n cotton states east of a n d including Texas. C 6
• Bakélite h a s introduced a n e w series of epoxy resins developed for corrosionresistant surface coatings. F o u r products are currently available, a n d comp a n y says t h e s e resins can b e formul a t e d into high-quality air-drying or baking finishes for steel, aluminum, • A d m i x t u r e for cementitious mixes zinc, tin plate, a n d wood. T w o of t h e provides up to 4 0 % higher ultimate products a r e designed to react with strength in less time a n d a possible amines, polyamides, a n d urea-formal15 96 savings in cement says its devel-* dehyde resins; one is in solution for easy oper, L. Sonneborn Sons' building prod handling, t h e other is a solid resin products division. N e w material, Sonotard, uct. T h e t w o others, primarily d e is designed t o slow u p setting of con signed to esterify with vegetable oil crete a n d mortar mixes allowing more acids, u n d e r g o epoxy reactions. C 7 effective control of rnixing, placing, and finishing. A t same time, company • Rust p r e v e n t i v e spray for use o n claims it produces higher compressive tools, molds, dies, instruments is being strength, reduced permeability, more p r o d u c e d b y Eastern Aerosol Products. homogeneous concrete, minimum Compound is k n o w n as Rust C h e k a n d shrinkage, a n d superior, denser finishes. is said t o provide coverage in t h e form of a clear, dry, waxy film. C o m p a n y V. I says except in t h e case of use on preci• All-purpose a l u m i n u m p a i n t that sion instruments w h e r e critical tolerproduces a simulated h a m m e r e d finish ances are to be held, the film n e e d n o t is offered b y Speco. Paint utilizes a be removed when the protected tool, specially formulated, doubly-pigmented or m a c h i n e r y is readied for use. C 8 aluminum base and is known as Halum. Coating is said to b e highly resistant ί» Temp il Corp. is offering a new T e m p i l to fumes, oils, grease, mild industrial Pellet for 100° F . Company says ship acids, and other common corrosive m e n t of t h e n e w low temperature pellets will be limited t o off-surnmer C2 agents. months; if stored during hot w e a t h e r • Contact c e m e n t , called Prestix Con t h e y will need mild refrigeration. C 9 tact Cement by Adhesive Products, • T w o silicone rubber compounds, malces possible contact decorating us ing any fabric, plastic, o r leather, says offered b y t h e Connecticut H a r d R u b company. I t is a liquid which, brushed ber Co., are said to possess tensile a n d on to wood o r metal and allowed to dry tear strengths a n d elongation properties 30 minutes or longer, will b o n d in m o r e than d o u b l e those of conventional stantly to materials such as plastic, silicone rubber. T h e compounds are fabric, leather, p a p e r . C 3 known as Cohrlastic H T 655 a n d H T 666. C o m p a n y says compounds owe ί T h e r m o s e t t i n g plastic, developed by t h e i r strength a n d abrasion resistance T h e Homalite Corp., does n o t support to use of an ester coated fine silica combustion. Company says t h a t al filler ( D u Pont's V a i r o n ) . CIO though it c h a r s w h e n direct flame is applied, it does not continue to b u r n Further useful information on when flame is removed. Called Homa keyed Chemical items men lite 101, n e w plastic is clear a n d almost tioned is r e a d i l y a v a i l a b l e . . . colorless. C4 *>•
RES©FLEX
one-step thick section curing are offered in commercial quantities b y Union Car b i d e and Carbon. T h e y come in either neutral or r e d color a n d are designated as K-1025 a n d K-1028 Silicone R u b b e r C o m p o u n d s . B o t h are said to h a v e v e r y low compression set. C 5
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1 Cambridge Industries Co.
Β Q|
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I
101 Potter Street
m
Cambridge 42, Mass. Please send me a laboratory sample of Resoflex R-296 and technical
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literature.
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Company
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Address
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1
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g City MARCH
State 2 6,
1956
C&EN
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