NEW CHEMICALS
for rapidly samples
converting
of polar
materials
into volatile trimethylsilyl for gas chromatographic
ethers analyses
SURE! Just use TRI-SIL and in 5 minutes you're ready to go!
Polymer Reference Standards Twelve polybutadienes, certified as to structure, or molecular weight distri butions, are available tor use in basic research and analytical work. Four of the standards are linear, narrow molec ular weight distribution, hydrogenated polybutadienes that an; certified as to the number average and weight average molecular weight. These reference polymers have less than one double bond per 1000 carbon atoms and less than 20 ethyl side chains per 1000 car bon atoms. Three of the polybutadienes are high in either cis, trans, or vinyl content; the unsaturation is certified by infrared spectrometry. Five linear polybuta dienes with narrow molecular weight distributions (uv. mol. wt. range of 17,000 to 423,000) can be used as molecu lar weight standards in gel permeation chromatography. Average molecular weights (number and weight) are de termined by light scattering and os motic pressure measurements. Certified analyses accompany shipments of these materials. Phillips Petroleum Co., Spe cial Products Division, Bartlesville, Okla. 501
Run SUGARS on a Gas Chrοmatοgraph?
TRI-SIL is a ready mixed, single solution of solvent, reagent and catalyst. TRI-SIL readily forms trimethylsilyl ethers of: CARBOHYDRATES, PHENOLS, ALCOHOLS, H Y D R O X Y — a n d KETO—STEROIDS and o t h e r POLAR COMPOUNDS. TRI-SIL OFFERS THESE ADVANTAGES, SIMPLICITY, BROAD APPLICA BILITY, SPEED, IMPROVED RESO LUTION, RELIABILITY, MINIMAL A N O M E R I Z A T I O N , CONVE NIENCE, LONGER COLUMN LIFE, and economy.
Silylating Reagents d a t a and references upon request.
PIERCE CHEMICAL COMPANY P.O. Box 117 Rockford, Illinois PHONE S15-96S-0747
TWX | 1 5 · 3 « | - β 0 · |
Circle No. 53 on Readers' Service Card
Value is a balance by Roller-Smith
Pure Compounds The 99% pure 1,3-diglycerides of myristate, palmitate, and oleate are available. These compounds are com pletely free of the 1,2 isomers and are homogeneous by chromatography. A photo of the thin layer chromato graphic analysis is furnished with each compound. Supelco, Inc., P. O. Box 5S1, Bcllefonte, Pa. 16823. 502
Model LG0500MG. • Range 500 mg. • Accuracy ± 1 . 0 mg. • Tared capacity 1500 mg. • Magnetically dampened • Only $ 2 9 0
Magnesia-Silica Gel Florisil (magnesia-silica gel) 60/100 PR has been specially processed to pro duce a selective adsorbent of consistent behavior for column cleanup and sepa ration of chlorinated pesticide residues prior to identification and measurement of the pesticides by gas, thin layer, or paper chromatography. This material meets the performance characteristics suggested by the Association of Official Analytical Chemists methods. Floridin Co., 375 Park Ave., New York, Ν. Υ. 10022. 503
The LG0500MG is the result of over 50 years experience in the precision balance field. And just one of 28 models made by Roller-Smith, ranging from 3 mg. to 50 grams. This complete line covers all appli cations, and includes a Universal Yarn Numbering Balance, a Ber-
man Density Balance and the unique Rosano™ Surface Tensiometer. Prices? Remarkably reason able. Remember: for precision balances, look to Roller-Smith first. ROLLER SMITH PRECISION BALANCES Federal Pacific Electric Co.. 50 Paris Street. Newark. N. J .
Circle No. 2G on Readers' Service Card
VOL 39, NO. 2, FEBRUARY 1967
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201 A
