NEW CHEMICALS
T h r e e new Ultrex h i g h - p u r i t y o r g a n i c research m a t e r i a l s b r i n g t o 10 t h e n u m b e r of z o n e - r e f i n e d p r o d u c t s a v a i l a b l e . T h e new o n e s are: b e n z i l , p h e n a n t h r e n e , a n d t r a n s - s t i l b e n e ; al ready available are: acenaphthene, anthracene, biphenyl, d u r e n e , n a p h t h a l e n e , p y r e n e , a n d pt e r p h e n y l . T h e s e m a t e r i a l s are a s s a y e d w i t h gc a n d d i f f e r e n t i a l s c a n n i n g c a l o r i m etry, have a m i n i m u m 99.95% purity, are e v a l u a t e d for t r a c e c o n t a m i n a n t s by t w o or m o r e t i c p r o c e d u r e s a n d by m e l t i n g p o i n t , a n d are p r o v i d e d w i t h a c e r t i f i c a t e of analysis. J . T. Baker C h e m i c a l Co. 201-859-2151 431 Reference standard solutions for polychlorinated biphenyls are s u p p l i e d in s e p t u m t o p b o t t l e s . C o n c e n t r a t i o n s of 10 or 100 p p m in b e n z e n e are p r o v i d e d , w i t h d i l u t i o n a c c u r a c y of b e t t e r t h a n 0.5%. D u k e S t a n d a r d s Co. 415-328-2400 432 Gel electrophoresis kits for molecularw e i g h t e s t i m a t i o n s by use of SDS-polya c r y l a m i d e gel e l e c t r o p h o r e s i s a n d for p o l y a c r y l a m i d e gel e l e c t r o p h o r e s i s itself e a c h c o n t a i n 100 g r a m s of t h e c o m p a n y ' s electrophoresis purity grade acrylamide a n d p r o p o r t i o n a t e q u a n t i t i e s of all a d d i t i o n a l m a t e r i a l s for gel m e d i a prepara t i o n . No f u r t h e r recrystallizations or v a c u u m d i s t i l l a t i o n s are r e q u i r e d . Prices s t a r t a t $45. Bio-Rad Laboratories. 415234-4130 433 Twenty-one cholesteric liquid crystal solutions are available in n o n f l a m m a b l e s o l u t i o n . T h e s o l u t i o n s are u s e f u l in t h e m e a s u r e m e n t of surface t e m p e r a t u r e s , d e t e c t i o n of s u r f a c e v a r i a t i o n s , or in n o n d e s t r u c t i v e t e s t i n g w h e r e flaws p r o d u c e h e a t flows. Brilliant color c h a n g e s over relatively narrow t e m p e r a t u r e ranges c h a r a c t e r i z e t h e r e s p o n s e of t h e s e m a t e rials. T h e c o m p a n y lists 50 liquid crystal c o m p o u n d s w h i c h cover a w i d e range of t e m p e r a t u r e levels. M C / B M a n u f a c t u r i n g C h e m i s t s . 513-631-0445 434 QDH reagent kit for r a p i d s c r e e n i n g a n d c o n f i r m a t i o n of sickle cell a n e m i a a n d t r a i t by a 20-min Quick-Disc electrophoretic s e p a r a t i o n of h e m o g l o b i n frac t i o n s requires o n l y a finger-stick of w h o l e b l o o d . T h e r e are no false positives. Canalco, Inc. 301-881-8090 435 Seloxcette, c h r o m i c a n h y d r i d e in g r a p h ite, is a new reagent for t h e specific o x i d a t i o n of p r i m a r y a l c o h o l s to alde hydes. It c o n s i s t s of 55-60% Cr0 3 in g r a p h i t e ; it d o e s n o t oxidize s e c o n d a r y or t e r t i a r y a l c o h o l s . V e n t r o n Corp. 617922-1875 436
FAST QUANTITATIVE Fatty Acid Esterification These exciting new reagents offer signi ficant advantages over other methods for the preparation of alkyl esters and other derivatives for gas phase analysis. SPEED — Most reactions are c o m p l e t e as s o o n as s o l u t i o n is a c h i e v e d . C O N V E N I E N C E — One step procedure; ready-to-use reagents in Hypo-vials. CHOICE OF DERIVATIVE Methyl, Ethyl, Propyl, η-Butyl or t-Butyl; t-Butyl esters are f o r m e d as easily as methyl esters. Q U A N T I T A T I O N — Quantitative yields are obtained — even w h e n reagent and sample are injected without prior mixing. These significant new reagents may be ordered as listed in the next c o l u m n . A
technical bulletin is available on request; just ask for "Alkyl-8 Bulletin." O r d e r as follows: 4 9 3 5 0 METHYL-8™, D M F DIM E T H Y L A C E T A L 2 m e q / m i . in Pyridine $16. 25ml 4 9 3 3 0 ETHYL-8™, D M F D I E T H Y L A C E T A L 2 meq / m l . in Pyridine $16 10ml 4 9 3 6 0 PROPYL-8™, D M F D I P R O P Y L A C E T A L 2 meq /ml in Pyridine S16/10ml 4 9 3 1 0 n-BUTYL-8™, D M F - D I - n - B U T Y L ACETAL 2 m e q . / m l . in Pyridine S16/10ml 4 9 3 2 0 t-BUTYL-8™, DM F-DI-t-BUTYLACETAL 2 meq ml in Pyridine $16 10ml
PIERCE CHEMICAL COMPANY P.O. Box 117 Rockford, Illinois 61105 U.S.A. PHONE 8I5/96B-0T47
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Molecular weight ι
Nakos and Mortenson 1 .) B i o - R a d offers highly purified and tested r e a g e n t s for S D S - a c r y l a m i d e gel e l e c t r o p h o resis: acrylamide. ^ Bis, S D S . T E M E D , R a p i d and a c c u r a t e a m m o n i u m p o l y p e p t i d e mo pe rs u I f a t e , χ \ lecular weight 2- mercaptoestimationscan ethanol and -' 4 T·^ be a c h i e v e d C o o m a s s ie J Σ. ^V α with tho S D S brilliant blue acrylamide '3 \ R-250. Purgel e l e c l r o chase t h e m 5-3 \ phoresis singly or in | Azo Fd Q^ 5 technique. the SDS ο \ Tho key is a Acrylamide I -2 \ potent pro Kit. which tein dénaturcontains ant and solurepresentaElectrophoretic Mobility bilizing agent, tive quantities 1 1 1 ! 1 1 SDS (sodium of e a c h rea.1 .2 .3 .4 .5 .6 .7 d o d e c y l sulfate) gent. Like to Molecular weight estimation of the polypeptide It binds to p r o k n o w more about chain of Azoferrodoxin from 4 standard curves. Marker proteins were: 1. catateins to c a n c e l difBio-Rad's prodlase, 2. fumarase, 3. aldolase, 4.glyferences in intrinsic ceraldehyde phosphate dehyA ucts for gel elecc h a r g e a n d converts ^ t r o p h o r e s i s ? Write for drogenase, 5. alpha-chy^^m their s h a p e to rod-like m0 r S 9 Price List X with six ML·^ 6 ^y igîo bin. *' ^ j â l particles w h o s e lengths pages devoted to reagents, vary u n i q u e l y w i t h their p r o materials and apparatus for this tein m o l e c u l a r weight. (See e x a m p l e rapidly g r o w i n g t e c h n i q u e ,
Molecular weight estimations using Bio-Rad's SDS Acrylamide Gel IP 7 Electrophoresis W 6 ,
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Nakut, G.
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anil Morlerson. L.. Biochemistry
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BIO-RAD Laboratories 32nd & Griffin Ave., Richmond, CA 94804, Phone (415) 234-4130 Also in: Rockville Centre. Ν. Υ.; St. Albans, England; Milano; Munich CIRCLE 23 O N READER SERVICE CARD
ANALYTICAL CHEMISTRY, VOL. 44, NO. 12, OCTOBER 1972
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Required reading for better Chromatographic separations... SEQUENTIAL ANALYSIS •vlWnPCHROMAT«*AmY
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AN INTRODUCTION TO
HIGH-SPEED LIQUID CHROMATOGRAPHY
WHAT LIQUID CHROMATOGRAPHY CAN DO FOR YOU
MONITOR AND CONTROL OF CHROMATOGRAPHIC COLUMNS USING THE R-400 SERIES REFRACTOMETER
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Consider Waters' library of liquid chromatography information your resource for solving separations problems. We've got factual, concise, and help ful monographs on a wide variety of topics. They are yours for the asking. Send for our complete Applications Index today. (If your separations problem is more pressing, give us a call and we'll do our best to help you)
WATERS ASSOCIATES 61 Fountain Street Framingham, Massachusetts THE LIQUID CHROMATOGRAPHY PEOPLE CIRCLE 2 1 8 O N READER SERVICE CARD
New Chemicals Ausria-125 for hepatitis detection is a newly licensed diagnostic test. In the Ausria test of a blood sample, which ig,a radioimmunoassay process, a radioactive tracer will link with hepatitis-associated antigen if it is present. A radioactivity counter then identifies and measures the level of antigen present. Abbott. 312688-3930 437
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Alkyl-8 family of reagents is convenient for the formation of methyl, ethyl, propyl, π-butyl, and t-butyl esters of fatty acids for gc analysis. The dimethylformamide dialkyl acetal reagents are stable at room temperature and packaged, ready-touse, in Hypo-vials. Pierce Chemical Co. 815-968-0747 438 Chemical identification kit, briefcase size, contains 1000 organic chemicals. Quantities of 1 ml or 1 gram are arranged by functional groups. Kit can serve as source of reference materials. $495; any one of five 200-unit sections is $99.50. Chem Service, Inc., West Chester, Pa. 439 Silar-5CP is a new high-temperature and high-polarity gas-chromatography phase. It will withstand temperatures up to 250°C for prolonged periods and can be exposed to 270°C for brief periods. Prom ising applications of this material are in the separation of mixtures of saturated, unsaturated, and polyunsaturated fatty acid methyl esters in the range,C20 and above. $35/10 grams. Applied Science Laboratories. 814-238-2406 440 Gas calibration standards, Mini-Cal, are certified to contain ± 2 % of the stated concentration of the gas. Each aerosoltype container holds 4 liters and is sup plied with two applicator tubes, one with a needle tip and one capable of accept ing a gas syringe needle. Nineteen gases are supplied in concentrations of 1000 ppm in helium. $12 each. Applied Sciience Laboratories. 814-238-2406 441 DNA-grade hydroxylapatite for the sep aration of nucleic acid components, called Bio-Gel HTP, is specially processed and then sized into an extremely narrow particle-size range. The material also shows a higher selectivity for doublestranded DNA over single-stranded DNA. It is a stable dry powder and costs $28/ 100 grams and $125/500 grams. Bio-Rad Laboratories. 415-234-4130 442 Mercury standard in gelatin simulates mercury-containing biological samples for interlab comparisons in mercury deter mination and for checking instrument, operator, and processing variabilities. The material is supplied as mercury stan dard in gelatin, 0.03 ppm, No. 11624, and mercury standard in gelatin, 0.1 ppm, No. 11626. Eastman Kodak Co. 716-724-4642 443
Potassium C h l o r i d e is a superior IR replacement w i n d o w . W h y ? Because it p r o v i d e s : • Better Transmission • Longer Life • Lower Solubility • Ease in Polishing • L o w e r Index and t h e price is the same as salt ( N a C I ) . W e also sell NaCI as w e l l as A L L replacement w i n d o w s for every IR s p e c t r o p h o t o m e t e r available. W r i t e us for more i n f o r m a t i o n — or call 2 1 6 / 2 4 8 / 7 4 0 0 .
HARSHAW
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The Harshaw Chemical Company Division of Kewanee Oil Company Crystal & Electronic Products Dept. 6 8 0 1 Cochran Road, S o l o n . Ohio 4 4 1 3 9 CIRCLE 9 4 O N READER SERVICE CARD
ANALYTICAL CHEMISTRY, VOL. 44, NO. 12, OCTOBER 1972
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