ISOMET CORPORATION

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BRIEFS Enzymatic Determination of Polyunsaturated Fatty Acids 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. JOSEPH MacGEE, The Procter and Gamble Co., Cincinnati, Ohio Anal. Chem. 31,298 (1959) Spot Tests for Aromatic Compounds Using 2,4,7- Trinitroftuorenone A qualitative spot test for aromatic compounds is devised by spraying spots on filter paper with 2,4,7-trinitro- fluorenone. 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. 31,302 (1959) Analysis of Long-Chain Fatty Acids by Gas-Liquid Chromatography. Micromethod for Preparation of Methyl 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 gas- liquid 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 21, Ν. Υ. Anal. Chem. 3 1 , 307 (1959) Determination of Quinquevalent, Trivalent, and Organic Phosphorus in the Atmosphere and in Aqueous 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) Microdetermination of Acetone in Biological Fluids A micromethod for determining acetone is based on the diffusion of the acetone on a filter paper strip into 2,4- dinitrophenylhydrazine 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. 31, 311 (1959) NaCI KBr CsBr Csl CELL WINDOWS FOR INFRARED SPECTROMETERS All commonly used cell windows stocked for im- mediate shipment. Available either polished and optically flat or in the form of cleaved or sawed blanks. Special cell windows made to order. Let us quote on your requirements. ISOMET optical cell windows have excellent trans- mission characteristics and are precision finished. Repair Service available for damaged cell windows and prisms. Attractive prices enable you to stretch your labora- tory budget. Write for Technical Bulletin 7 57K ISOMET CORPORATION P. 0. Box 346 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 SADTLER... STANDARD 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 COMMERCIAL 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 SADTLER RESEARCH LABORATORIES SERVICES 1517 VINE STREET LOcust 4-0835 PHILA. 2, PA. Circle No. 75 on Readers' Service Card VOL. 31, NO. 2, FEBRUARY 1959 · 1 7 A

Transcript of ISOMET CORPORATION

Page 1: ISOMET CORPORATION

BRIEFS E n z y m a t i c D e t e r m i n a t i o n o f P o l y u n s a t u r a t e d Fa t ty A c i d s

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, microorgan­isms, and plant seed with good sensitivity and accuracy.

JOSEPH MacGEE, The Procter and Gamble Co., Cincinnati, Ohio

Anal. Chem. 31,298 (1959)

Spot Tests fo r A r o m a t i c C o m p o u n d s U s i n g 2 , 4 , 7 -Tr in i t ro f tuorenone

A qualitative spot test for aromatic compounds is devised by spraying spots on filter paper with 2,4,7-trinitro-fluorenone. 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. 31,302 (1959)

A n a l y s i s o f L o n g - C h a i n Fat ty A c i d s b y G a s - L i q u i d C h r o m a t o g r a p h y . M i c r o m e t h o d for P r e p a r a t i o n 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, sep­arated in pure form by sublimation, ate ready for gas-liquid chromatographic studies. The technique elimi­nates saponification with its several disadvantages.

WILHELM STOFFEL, FLORENCE CHU, and E. H. AHRENS, Jr., Rocke­feller Institute, New York 2 1 , Ν. Υ.

Anal. Chem. 3 1 , 307 (1959)

D e t e r m i n a t i o n o f Q u i n q u e v a l e n t , T r i v a l e n t , a n d O r g a n i c Phosphorus in the A t m o s p h e r e a n d in A q u e o u s Solut ions

A method for determining quinquevalent, trivalent, and organic phosphorous in mixtures is based on the oxida­tion of organic phosphorous with alkaline ammonium persulfate. Calculations are made by differences. Ap­plication is made to atmospheric and aqueous phos­phorous 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 in B io log ica l Fluids

A micromethod for determining acetone is based on the diffusion of the acetone on a filter paper strip into 2,4-dinitrophenylhydrazine solution. The color produced after the addition of sodium hydroxide is read in a photo­electric 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)

NaCI KBr CsBr Csl

CELL WINDOWS FOR INFRARED

SPECTROMETERS • All commonly used cell windows stocked for im­

mediate shipment. Available either polished and optically f lat or in the form of cleaved or sawed blanks.

• Special cell windows made to order. Let us quote on your requirements.

• ISOMET optical cell windows have excellent trans­mission characteristics and are precision finished.

• Repair Service available for damaged cell windows and prisms.

• Attractive prices enable you to stretch your labora­tory budget.

Write for Technical Bulletin 7 57K

I S O M E T CORPORATION

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... STANDARD 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

COMMERCIAL 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 SADTLER RESEARCH LABORATORIES SERVICES 1517 VINE STREET LOcust 4-0835 PHILA. 2, PA.

Circle No. 75 on Readers' Service Card

VOL. 3 1 , NO. 2, FEBRUARY 1959 · 1 7 A