BRIEFS Enzymatic Acids
Determination o f Polyunsaturated
Fatty
JOSEPH MacGEE, The Procter and Gamble Co., Cincinnati, Ohio
S p o t Tests f o r A r o m a t i c Trinitroftuorenone
Compounds
Using
2,4,7-
A qualitative spot test for aromatic compounds is devised by spraying spots on filter paper with 2,4,7-trinitrofluorenone. Color and fluorescence vary with the type of aromatic compound reacting. Certain complexes are extractable in iso-octane and ethyl alcohol. H. T. GORDON and M. J. HURAUX, University of California, Berkeley, Calif. Anal. Chem. 3 1 , 3 0 2 (1959)
CsBr
Csl
CELL WINDOWS FOR INFRARED SPECTROMETERS
A rapid enzymatic method is developed for determining polyunsaturated fatty acids using lipoxidase. The enzyme produces the conjugated diene hydroperoxide which is measured at 234 πΐμ. Direct measurements are made in fats, oils, fatty acids, blood plasma, microorgan isms, and plant seed with good sensitivity and accuracy.
Anal. Chem. 3 1 , 2 9 8 (1959)
KBr
NaCI
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Write for Technical Bulletin 7 57K
ISOMET CORPORATION A n a l y s i s o f Long-Chain Fatty Acids b y Gas-Liquid Chromatography. Micromethod for Preparation o f M e t h y l Esters A technique is devised for the quantitative formation of methyl esters of long-chain fatty acids. The esters, sep arated in pure form by sublimation, ate ready for gasliquid chromatographic studies. The technique elimi nates saponification with its several disadvantages. WILHELM STOFFEL, FLORENCE CHU, and E. H. AHRENS, Jr., Rocke feller Institute, New York 2 1 , Ν. Υ. Anal. Chem. 3 1 , 307 (1959)
Determination of Quinquevalent, Trivalent, a n d Organic Phosphorus in the A t m o s p h e r e a n d i n A q u e o u s Solutions A method for determining quinquevalent, trivalent, and organic phosphorous in mixtures is based on the oxida tion of organic phosphorous with alkaline ammonium persulfate. Calculations are made by differences. Ap plication is made to atmospheric and aqueous phos phorous content. ROY MAY, Tennessee Valley Authority, Wilson Dam, Ala. Anal. Chem. 3 1 , 308 (1959)
M i c r o d e t e r m i n a t i o n o f A c e t o n e i n Biological Fluids A micromethod for determining acetone is based on the diffusion of the acetone on a filter paper strip into 2,4dinitrophenylhydrazine solution. The color produced after the addition of sodium hydroxide is read in a photo electric colorimeter. Interference due to acetaldehyde can be calculated. Method is applicable to biological materials. M. U. TSAO, G. H. LOWREY, and E. J. GRAHAM, University of Michigan Medical School, Ann Arbor, Mich. Anal. Chem. 3 1 , 311 (1959)
P. 0 . Box 3 4 6 Palisades Park, N . J . —SPECIALISTS IN CRYSTAL GROW/NG AND FABRICATION— Circle No. 57 on Readers' Service Card
Locate and Interpret
SPECTROGRAMS FASTER-EASIER WITH
S ADTLER... S T A N D A R D SPECTRA—MIDGET EDITION • A really serviceable collection of 13,750 usableorganiccompounds • Indexed by ASTM-IBM cards—5 Indices—Specfinder • Identification not complete until compared with known spectra 5 SADTLER INDICES • Alphabetical—Chemical Classes—Empirical Formula • Numerical—Uses, Alphabetical SPECFINDER • Reduces time for locating, examining and verifying Spectra to 2 or 3 minutes • Reduces need and expense of mechanical sorter • Answers inadequacies of shaker and machine sorter systems C O M M E R C I A L SPECTRA • Twenty five groups of usable materials like Surface Active Agents, Rosins, Plasticizers, Polyols, Soaps, Fatty Oils, Drying Oils, Waxes, Polymers and Pigments and Dyes. SA0T /I
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1517 VINE STREET LOcust 4-0835 PHILA. 2, PA. Circle No. 75 on Readers' Service Card VOL. 3 1 , NO. 2, FEBRUARY 1959 ·
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