NEWS
NOW detonations in less than For
minute
GEOLOGICAL CORES
GRAINS
FOODS WOOD PAPER COAL and many other materials with the
TEXTILES TOBACCO
SCHLUMBERGER Ν MR Analyzer
This Girl performs 2 5 0 moisture determinations daily a n d
Gives
This Chemist fast, a c c u r a t e d a t a for process improvement and quality control
Non-destructive moisture testing of solid product samples by the NMR (Nuclear Mag netic Resonance) method makes tremendous savings in time and money. •The large (40 cc) sample size allows high sampling accuracy. Results are reproducible to parts per thousand with accuracy of 0 . 1 % absolute. For complete information, including materialstudy reports, write to Department AC-10
RIDGEFIELD INSTRUMENTATION
DIVISION
and the recovered fractions analyzed quantitatively by ultraviolet absorp tion techniques. Work in this area has been carried out by Ε. Μ. Bens and W. R. McBride, U. S. Naval Ordnance Test Station. These mixtures are formed by oxida tion of 1,1-dialkylhydrazines. In very complex mixtures of tetraalkyltetrazenes, some isomers were partially separated. Automatic Titrator. Completely automatic titrations are now possible with a new instrument made in London, England, by Baird and Tatlock. Oper ation of the instrument was outlined by D. A. Patient. Where many similar titrations have to be carried out in continuous succession, Patient said, errors can creep in due to sample prep aration and measurement and accuracy in noting and interpreting the buret reading. The present instrument has a fully automatic control unit so that the whole series of operations in a titration can be performed independently of the operator. The instrument includes end point detection circuits, automatic sampling, photoelectric determination of titrant meniscus in the buret, and a digital printed record of the titration result. Time is also recorded to pro vide sample identification. The instru ment is in commercial production and is handled in the U. S. by Chicago Apparatus Co. Polarographic Reductions. As a result of his studies of the role of the supporting electrolyte in polarographic reductions, W. H. Reinmuth, Columbia University, has developed an explana tion for cases which cannot be explained in terms of nonspecific influence on the structure of the double layer. He considered the theory relating to the electron transfer process at elec trodes with regard to predictions in the reductions of anions. He feels that electron-transfer controlled (irre versible) reduction of anions cannot be initiated in a potential region beginning near the electrooapillary maximum and extending to more cathodic po tentials. Apparent contradictions can be explained in terms of ion-pair formation prior to reduction. Metallochromic Indicators. Effec tive use of metallographic indicators in chelometric titrations requires un derstanding of the various factors in volved, C. N. Reilley, University of North Carolina, stated. There are sev eral competing equilibria involved. Significance of these equilibria may be presented pictorially by pM-pH or Ργ-ρΗ diagrams. The sharpness of an end point may be completely and quan titatively characterized by two end point indices taken from such diagrams.
SCHLUMBERGER WELL
S U R V E Y I N G
C O R P O R A T I O N
Ridgefield,
Connecticut
Circle No. 48A-1 on Readers' Service Card, page 101 A 48 A
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ANALYTICAL CHEMISTRY
Analytical Grade
AMBERLITE Ion Exchange Resins AMBERLITE IR-120 (H)* —strongly acidic cation exchange resin deriving activity from sulfonic acid groups.
AMBERLITE IR-45 (OH)* —weakly basic anion exchange resin deriving activity from primary, secondary and tertiary amine groups.
AMBERLITE IRC-50 (H)* —weakly acidic cation exchange resin deriving activity from slightly ionized carboxylic-acid groups.
AMBERLITE IRA-400 (CI)* —strongly basic anion exchange resin deriving activity from quaternary amine groups. Supplied as the chloride salt.
AMBERLITE IRA-401 (CI) —similar to IRA-400, but is of high porosity. *Also available in chromatographic grade.
Among the many problems f o r which these resins should be considered ore: • adsorption o f organic bases · the exchange o f metallic cations · research into all types o f basic materials—par ticularly proteins (amino acids), alka loids, enzymes, dyes, vitamins and salts of weak acids · adsorption and fractionization o f weak acids · isolation and purification o f pharmaceuticals * general anion exchange reactions · water conditioning · acidic o r alkalinecatalyzed organic syntheses · removal of acids from reaction mixtures · recov ery a n d separation o f metals a n d rare earths. Laboratory quantities ( 2 5 pounds or less) o f these highly purified Amberlite Analytical G r a d e ion exchange resins are a v a i l a b l e exclusively through local offices of:
FISHER SCIENTIFIC CO. PRICES AND ADDITIONAL INFORMATION W i l l BE SENT UPON REQUEST. PURCHASES OF QUANTITIES IN EXCESS OF 25 POUNDS SHOULD BE MADE THROUGH OUR OFFICE.
Chemicals for Industry
ROHM & HAAS COMPANY THE RESINOUS PRODUCTS D I V I S I O N Washington Square, Philadelphia 5, Pa. Representatives in principal foreign countries Circle No. 48 A-2 on Readers' Service Card, page 101 A
