RESEARCH
Dowel! Adds to Research Facilities Chemical service c o m p a n y ' s n e w l a b is e q u i p p e d w i t h tools f o r research in r a d i o c h e m i s t r y TULSA, OKLA.—Expanding its research facilities to keep pace with the firm's growth, Dowell, Inc.—a wholly owned D o w subsidiary—has completed and put into service an addition to its chemical research laboratory here. The addition increases Dowell's laboratory space by 14,000 square feet. It provides room needed for research in organic, inorganic, physical, and analytical chemistry, in physics, bacteriology, a n d radiochemistry. Offices, conference rooms, an enlarged library, shops, storeroom, snack bar, and reception area are also included in the structure. Dowell is a chemical service company, providing a n extensive group of services and products for completion and workover operations on oil and gas wells. I t also furnishes chemical cleaning service for industrial equipment such as boilers, heat exchangers, lines, and various types of process equipment. Recent research has b e e n along the lines of developing new formation-fracfniMT-irr
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cementing compositions, methods of controlling loose sand in wells, and improved solvents for removing scale deposits from industrial equipment. Most recent product of Dowell's research labs
is Detex—the new oil well cement (C&EN, Jan. 9, page 1 7 8 ) . • Analytical Lab. Of particular interest in the n e w laboratory are the instrument analysis a n d radiochemistry laboratories. T h e former is equipped with the most up-to-date instruments and tools for both routine a n d research work dealing with analytical chemistry. These include: electron microscope, optical emission spectograph, x-ray emission spectrograph, infrared spectrophotometer, and x-ray diffraction units. The radiochemistry laboratory is equipped with stainless steel laboratory benches, stainless steel hoods for processing radioactive materials, and a specially designed floor storage compartment. T h e latter is for storage of highlyactive radiochemical products and is made of ferrophosphorus concrete. • Born in a Trailer, Dowell's first laboratory facilities in t h e midcontinent area were contained in a house trailer. This portable laboratory, p u t into service in 1934, was used mainly for the analysis of oil field samples and field development studies. It was hauled behind a car or truck to the well site. Chemical research on n e w materials and services was done at that time
in Dow's main laboratories at Midland. By 1936, Dowell h a d need for enlarged facilities to provide m o r e rapid and improved service to the company's customers and t o conduct research leading to n e w and improved products and services. The first permanent laboratory was constructed in the corner of a company warehouse in Tulsa. A year later a new laboratory was opened. This building is still used a s Dowell's mechanical research laboratory.
For more pictures of Dowell's new laboratory, turn to News Focus, page 306. T h e rapid growth of Dowell made it necessary in 1953 to build a. new and larger chemical research laboratory. It was located on t h e site of the company's operational headquarters, shops, warehouses, a n d manufacturing plants. T h e present expansion is t h e most recent in t h e series to keep p a c e with t h e company's growth. Dowell, a pioneer in the chemical service field, now operates from 165 points in the United States a n d Canada. A subsidiary, United Oil well Services, S. A., offers chemical services in northern South America. It also operates chemical manufacturing plants near Maracaibo and at Anaeo, Venezuela.
Good-by to Benzpyrene? Ammonium compounds will reduce possible carcinogen in cigarette smoke
Dowell's instrument analysis laboratory is well equipped for both routine and research analytical work. It has an optical emission spectrograph, electron microscope, x-ray emission spectrograph, and infrared spectrophotometer 224
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ATLANTA—Seeking to reduce possible carcinogenic c o m p o u n d s in cigarette smoke, research chemists S. Z. Cardon and E . T. Alvord of Rand D e velopment have found that impregnation of cigarette papers with ammonium salts will inhibit formation of one of t h e suspects, 3,4-benzpyrene, by as much as 60% (C&EN, Nov. 1, 1954, page 4 3 8 0 ) . Cigarette p a p e r s contribute only 2 5 % of the benzpyrene produced in cigarette smoke. Ammonium salts counteract additional amounts ( 3 5 % ) of benzpyrene produced b y the tobacco itself, Cardon and Alvord told the recent meeting in Atlanta of the American Association for the Advancement of Science. From the floor, Louis Fieser of Harvard said he does not consider the identification b v Cardon a n d Alvord
Less t h a n
RESEARCH
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S. Z. Cardon (standing) and E . T. Alvord of R a n d Development use a n ultraviolet light source to get preliminary indication of separation of cigarette tars
complete. T h e evidence they present, and which has been presented in England, does not constitute proof that the substance is benzpyrene. What they have done, says Fieser, is to identify a benzpyrenelike substance. Fieser has also been studying the problem and says h e cannot find benzpyrene in smoke in quantities suflBcient to cause cancer. Cardon and Alvord first established controlled smoking conditions using a machine designed by American Tobacco's research laboratory and then developed analytical procedures for 3,4-benzpyrene. T h e "smoking machine," a commercially available smoke sampling apparatus, inhales each cigarette separately— a 60 cc. inhalation once a minute. This comes close to average conditions in actual smoking, say its users. T h e cigarette smoke was drawn through three acetone traps to condense and dissolve the smoke. Cardon and Alvord then extracted the acetone layer with cyclohexane and dried the cyclohexane extract. Benzpyrene was separated chromatographically in successive alumina and silica gel columns using benzene as the column developer. Actual identification was performed by three methods: fluorescent spectra, ultraviolet absorption spectra, and comparison of ultraviolet absorption spectra for iodinated combustion products from the column with pure 6iodo-3,4-benzpyrene. Absorption intensity studies at given wave lengths determined quantity.
The benzpyrene content averaged 2.5 micrograms p e r package of cigarettes with no significant difference found between several popular brands. • To Inhibit. After Cardon a n d Alvord identified and made qualitative and quantitative analyses of 3,4-benzpyrene in cigarette paper, they t u r n e d to compounds which might inhibit benzpyrene formation. Over a twoyear period, they investigated several hundred, ranging from inorganic to organic salts—oxidizing and r e d u c i n g agents, dehydrating agents, inorganic and organic amines, and especially ammonium salts. The majority h a d little or n o effect on benzpyrene formation. Some—particularly calcium and b a r i u m chlorides—even increased the a m o u n t of benzpyrene in tars from smoked cigarettes. C o m p o u n d s which give off a m m o n i a are most effective in reducing b e n z p y rene found in products from cigarette smoke. For example, 5% a m m o n i u m sulfamate by weight in t h e p a p e r reduced benzpyrene in tar from b u r n e d cigarette p a p e r by 9 5 % . W h e n ammonium sulfamate-treated p a p e r cigarettes were "smoked" on the machine under controlled conditions, the b e n z p y r e n e produced was r e d u c e d 609£, compared to cigarettes with t h e same tobacco and untreated paper. Since Cardon and Alvord found a greater reduction in benzpyrene from cigarettes made of treated p a p e r , they conclude that ammonium sulfamate also reduces benzpyrene coming from a cigarette's tobacco. • Treating Paper. Cardon and Al-
Ask f o r S&S " A s h - F r e e " A n a l y t i c a l Filter Papers For m a n y years S&S Ash-Free Analytical Filter Papers have been known for t h e i r extremely low ash content. They h a v e been t h e choice of chemists w h o must have t h e most precise working tools. T o our [knowledge, there is no filter paper w i t h lower ash content on the market. In fact, ash content of S&S Quantitative Papers is considerably lower t h a n all other papers w e have tested—less than 0.007%. Ask y o u r laboratory supply house for S&S A n a l y t i c a l F i l t e r P a p e r s — t h e finest, most precise filter paper you can specify. Yet S&S quality costs no more. I£ you would like to receive a free S&S Filter Paper Sampler, m a d e u p of m a n y g r a d e s , just m a i l t h e coupon "below. MAIL THIS COUPON FOR FREE SAMPLER
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Gentlemen: Please send me, f r e e , a n S&S Analytical Filter P a p e r S a m p l e r .
JAN.
16,
1956
.State.
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RESEARCH
vord use three methods for treating cigarette papers: • For relatively water soluble compounds, paper is drawn through water solutions of t h e test compound and dried by heat lamps in a continuous process moving at approximately four feet per minute. • For organic compounds, drawn through a solution of acetone. • For insoluble inorganic compounds (such as aluminum oxide) a two bath dip—pickup and precipitation. Inhibitor concentrations ranging from 5 to 10% of paper weight were sought. Controlling paper speed and solution concentration give desired weights. When the first ammonium compound showed promise, researchers Cardon and Alvord concentrated on the ammonium salts. Extending their work, they found a relationship between effectiveness a n d quantity of ammonia given off. Thus for equal weights, dibasic salts are more effective than monobasic. Oxidizing ammonium salts —ammonium persulfate—also are effective, but to a lesser degree than ammonium sulfamate. Paper containing ammonium sulfate lost some of its effectiveness when burned more than a month after treatment. Cardon and Alvord surmise that some ammonia is lost through displacement by calcium from calcium carbonate in t h e paper. Looking further into aging problems, they find monobasic ammonium salts are more stable than dibasic salts. Although monobasic, ammonium sulfamate produces two active ammonia groups. The combination of stability and more ammonia gives ammonium sulfamate greatest effectiveness of all compounds Cardon a n d Alvord tested.
Quantum Advances Physical chemists shoot for prediction of structure a n d properties with energy computations JLx A RESURGENCE similar to that ex-
perienced by nuclear physics of the 1930's—leading to atomic fissionq u a n t u m chemistry is getting a great deal of worldwide attention. Researchers, n o w able to clear u p some inconsistencies t h a t puzzled chemists for years, are looking forward to t h e day when they can shorten the time from test t u b e to tank car. They're even hoping to take test tubes out of action 226
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Quantum chemistry will answer problems in crystal properties and structure, Laurens Jansen (left), University of Maryland, a n d Per-Olov Lowdin of Sweden's Uppsala University told the International Conference on Quantum Mechanics in some cases. Some of these points were suggested at the International Conference on Quantum Mechanics held recently at the University of Texas, Austin. T h e conference was sponsored by t h e National Science Foundation and industrial firms Convair Dow Humble, Magnolia, Monsanto, and Shell. Quantum chemistry's two objectives— to get a basic understanding of matter and to determine if a particular compound may have properties not found easily by experimental methods—are rapidly moving nearer their goals. Vastly improved computation techniques have been found and high speed electronic computers make possible calculations which could not heretofore be attempted. Quantum chemistry, a branch of quantum mechanics, involves calculating the energy level of a molecular structure and relating it to chemical and physical properties. A molecule's entire electron and atomic nuclei system must be considered—a most complex calculation. Based on a known compound's properties, structure, a n d energy calculated via quantum chemistry techniques, it is possible t o predict by more calculations, properties of compounds not yet synthesized. • Future Applications. Per-Olov Lowdin, Uppsala University, Sweden, emphasizes that preliminary work on simple molecules merely indicates future applications. H e says it may b e possible t o predict which molecule will give desired properties. This application will work in crystals.
Lowdin says crystals suitable for transistors have been predicted through quantum chemistry techniques. Early work along this line l e d to basic information in transistor development. For more than 130 years no one could an c \v /a r \ v h " /->*-•»'cfoic* epou: oinc= ticity. Researchers h a d assumed there were n o exceptions to the laws for bond energies, bond moments, and the like, but Lowdin showed there were exceptions which could b e predicted by the theory of nonadditive bond cohesion. Preliminary experimental work verifies calculated results for sodium and other alkali halide crystals. Laurens Jansen, University of Maryland, also working on crystal elasticity problems, has calculated energy of interaction for hydrogen and helium. Experiments show heavy rare gases (such as xenon) have very stable crystal forms at low temperatures and little phase change at even lower temperatures, a further verification of other calculations. Thus, as reliability of predictions improves, experimental work may be reduced to a minimum of making a few confirmations. • Carcinogenic Chemicals. Another possible application for quantum chemistry is prediction of carcinogenic activity. Bernard Pullman of Faculte des Sciences de Paris says 10 years' work now points to a chemical interaction between carcinogenic molecules and living cells. A metabolic process known as perhydroxylation occurs with carcinogenic aromatic hydrocarbons. This metabolic perhydroxylation forms the basis for a theory as to why certain aro-
