CHEMICALS
NEW
CHEMICALS
REAGENTS MATERIALS
Rare Earth Selenides A n u m b e r of rare e a r t h selenides, corresponding t o t h e 1:1 and 2 : ο com positions, is offered by Kleber L a b o r a tories, Inc. T h e company points outthat recent availability of rare e a r t h metals has stimulated interest in metal based derivatives, among the more u n usual of which are the rare e a r t h rhalcogenides. These p r o d u c t s have not yet been thoroughly characterized as to physical and electrical constants. T h u s , the company says, no claims for these can lie made. T h e only specification that can be placed on the material being offered, then, is the selenium content. The following are available: lan t h a n u m , 3 5 1 / ; ; to 3 6 1 / 2 % and 45 to 46% selenium for the 1 :1 and 2:8 com positions, respectively; neodymium, 84 L j ίο 35'/.>%• and 44 to 457c; ! gadolinium, 3 2 / 2 to 3 8 ' / ' 2 % and 42 to 48% ; dysprosium, 31 V 2 to 3 2 1 / 1 , % and 41» ._, to 4 2 V 2 % • : holmium, 3 Î y 2 to 321.• o'.'-v and 41 to 42',7 ; erbium, 81 to 82';,, and 4 0 V 2 to 4 1 V 2 % ; and v n i ' i u m , 46 to 4 7 % and 56 to 5 7 % .
priced at $375 a pound in quantities of one to four pounds and $325 a pound for five to nine pounds. A m o u n t s of less t h a n a pound are available at $1 a gram, with a packaging charge depending upon the size of the ampoules. Dow's cesium metal is silvery with a slight golden cast. It melts at 83° F., boil? at 1238° F., and has a density about twice t h a t of water. T h e metal, which is packaged in a vacuum or under argon gas, cannot exist a · an ele ment in air for more t h a n a few moments. W h e n free oxygen touches it, cesium bursts into flame and b u r n s with an intense glow. It explodes violently upon contact with water Dow sells cesium in steel and glass containers and also in a multi-ampoule " p o r c u p i n e " package. T h e latter is designed to assist researchers using the metal in small a m o u n t s . A number of g r a d u a t e d ampoules p r o t r u d e from the body of the glass package, and these can be sealed off individually without contaminating the metal. C-4
in t h e ultraviolet and infrared regions for m a x i m u m transmission. Quality and t r a n s p a r e n c y are preserved by packaging under an inert atmosphere. Copies of absorbanee curves are available from the company upon request. T h i r t y - f o u r solvents are on the M C & B list: acetone, acetonitrile, benzene, bromoform, butyl acetate, b u t y l ether, carbon disulfide, carbon tetrachloride, chloroform, cyclohexane, cyclopentane, 1,2-dichIoroethane, dichloromethane, A\A'-dimethyl formaline le. and yj-dioxane. Also listed are ether, ethyl acet a t e , ethyl formate, ethyl proprionate, glycerol, heptane, hexane, methanol, 2-methylbutane, methylcyclohexane, methyl formate, nitromethane, pentane, iso-propyl alcohol, pyridine, tetrachloroethylene, toluene, 2.2,4-trimethylpentane, and /«-xylene. C-3
High Purity Cesium Metallic cesium in a purity of over 99.9% is now available from T h e Dow Chemical Co. T h e alkali m e t a l is
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Tritiated Compounds Three new tritiated compounds are available from Schwarz BioResearch, Inc.—tritiated thymidine; tritiated adenosine 3',5'-cyclic p h o s p h a t e ; and tritiated deoxyuridine. T h e t h y m i d i n e has a specific activity of 6.25 curies per millimole, the highest ever available, claims the company. It is supplied in 5 0 % ethanol solution, and is said to be completely stable and rail iochemically p u r e as tested by isotope dilution and c h r o m a t o g r a p h y . About 20%. of t h e molecules contain tritium. The tritiated adenosine 3',5'-cyclie phosphate has a specific activity of 1.4 curies per millimole. The company -ays that this should be effective for precise study of the physiology and biochemistry of the compound, by autoradiographs in intact animals or isolated systems. T h e deoxyuridine has a specific activity of 1.6 curies per millimole. C - 2
CONTAMINATION-FREE AND QUALITY-GUARANTEED
Saxonburg
Spectroquality Solvents A complete line of reagents for spect r o p h o t o m e t r i c analyses is now offered b y M a t h e s o n Coleman & Bell. The c o m p a n y says t h a t each lot is checked
All combustion boats a n d crucibles m a n u f a c t u r e d by S a x o n b u r g are m a d e from h i g h e s t quality ceramic m a t e rials. Tests on each, lot g u a r a n t e e p u r ity. Careful inspection b y gloved personnel, a n d p a c k a g i n g in alumin u m foil or cans assures freedom from contamination. Immediate shipment possible on all s t a n d a r d sizes.
CERAMICS, INC.
Bulletin and free samples a v a i l a b l e on r e q u e s t . Letterhead, please. Circle No. 107 on Readers' Service Card
First Avenue Saxonburg, Pa.
VOL. 33, NO. 11, OCTOBER 1961
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