THE CHEMICAL WORLD THIS WEEK
SCIENCE
N e w iodine C o m p o u n d Ss infernal Antiseptic iodine-containing complex which gives give indications of being a coordina tion compound with polyvinylpyrrolidone has been found to exhibit the normal b a c tericidal, viruscidal, and fungicidal proper ties of elemental iodine but retains only a nominal toxicity toward h u m a n beings. T h e material has no caustic action on either skin or mucous m e m b r a n e a n d can b e taken internally in substantial quanti ties. Once introduced into the blood stream the iodine apparently is slowly liberated to act against bacteria, virus, a n d fungi. T h e clinical data on the ac tivity of the new compound is still incom plete b u t two years of clinical testing h a v e failed to reveal any side effects or sensiti zation from the administration of PVP-I. The iodine complex was discovered in 1949 by Herman A. Shelanski, a toxicologist at Philadelphia General Hospital w h o set out to confirm a G e r m a n report that polyvinylpyrrolidone concentrates tem porarily in t h e liver. In these investigations h e dissolved iodine in t h e P V P and found t h a t t h e result was something more t h a n a simple solution. Although the liquid could b e titrated for free iodine, it would not give t h e familiar starch test. More important it did not d a m a g e tissue as iodine does in even small concentrations. F u r t h e r tests revealed that t h e solutions r e t a i n e d the full activity of iodine against bacteria. Dr. Shelanski never d i d find out w h e t h e r PVT concentrates in t h e liver. He did find out, however, t h a t t h e PVP-iodine complex would form a continuous film which is impervious t o infection, which suggested a possible substitution for sur gical gloves. He found that PVP-I could b e easily washed off with water; a great advantage in hospitals and other places w h e r e iodine might b e used extensively as an antiseptic. And he found that it could b e applied in high concentrations to eliminate skin and throat infections safely. Of greatest potential significance was his discovery that the solutions could be ad ministered orally, in reasonably large doses w i t h o u t any ill effects, to a c t against sys temic infections, such as grippe a n d colds. General Aniline and Film Corp., which is the only American producer of P V P , originally sponsored Shelanski's work or t h e blood plasma substitute and has con t i n u e d to support t h e investigations of P V P - I . Gafco's central research depart m e n t has studied the complex and has found that there is a stoichiometric rela tionship b e t w e e n the iodine and the PVP molecules. T h e y have also d e t e r m i n e d that t h e r e is no detectable vapor pressure of
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iodine over the P V P "solution." F r o m these and other data they have p o s t u l a t e d that the complex may have the form:
(· Ε-I -I • < Ίί,>— X II iC II
c
I (\=_ (') •C.'II
PVP-I Further studies have indicated t h a t iodine forms similar complexes with o t h e r mole cules, some of the m o s t promising b e i n g the polyethylene oxides which h a v e d e t e r g e n t properties. A weak, nontoxic iodine complex with such a detergent material might produce an exceptional antisepticsoap. General Aniline officials said th«at t h e y intend to pursue the d e v e l o p m e n t of P V P I along with the P V P blood plasma s u b stitute until complete clinical examination indicates the exact extent of their value to medical practice. F u l l clinical reports on the work done this far will a p p e a r in t h e medical journals within the next few months.
Reversed-Phase C h r o m a t o g r a p h y A water-immiscible organic solvent has b e e n successfully u s e d as the stationary
p h a s e in partition c h r o m a t o g r a p h y , in ex p e r i m e n t s performed by t w o University of N o t t i n g h a m scientists, M. W. Partridge a n d J. Chilton. Eight milliliters of chloro form w e r e t h o r o u g h l y shaken with 8 0 g r a m s of 100-mesh borosilicate^ powder. T h e " w e t t e d " glass was a d d e d t o 100 ml. of w a t e r previously s a t u r a t e d w i t h chloro form. T h e mixture was then mechanically s t i r r e d until all t h e globules of chloro form w e r e disintegrated. Finally, t h e slurry was poured into a c h r o m a t o g r a p h i c c o l u m n a n d again thoroughly shaken. W i t h chloroform serving as the sta t i o n a r y p h a s e and w a t e r saturated with chloroform as the mobile p h a s e , it w a s possible t o m a k e almost q u a n t i t a t i v e r e coveries of t h e c o m p o n e n t s of mixtures c o n t a i n i n g 9 to 12 milligrams of onitroaniline a n d 9 to 12 milligrams of p-nitroaniline. Separations were also pos sible in t h e case of mixtures composed of 9 to 20 milligrams of o-nitrophenol a n d 12 t o 50 milligrams of p-nitrophenol. A m i x t u r e of 14 milligrams of hyoscine a n d 9 milligrams of hyoscyamine was only par tially s e p a r a t e d u n d e r similar conditions. H o w e v e r , w h e n t h e mobile aqueous phase w a s adjusted to approximately p H 9 b y t h e addition of sodium hydroxide and t h e solution was once again saturated with chloroform, p u r e hyoscine was recovered. T h e rexx)rt states t h a t these columns s h o w e d n o e v i d e n c e of b r e a k d o w n even 7 2 hours after preparation. In o n e experi m e n t , a c o l u m n e m p l o y e d in t h e separa tion of o- a n d p-nitroanilines was used a g a i n , w i t h o u t further t r e a t m e n t , for t h e s e p a r a t i o n of o- a n d p-nitrophenols. U n d e r t h e title, " R e v e r s e d - P h a s e Parti tion C h r o m a t o g r a p h y , " a brief description of this e x p e r i m e n t a l work is contained in t h e British journal, Nature, 167, 79 ( J a n . 13, 1 9 5 1 ) .
ΙΗΙΜϊΙββ
Cadmium Sulfide Crystal Use Opens N e w Fields, Says GE n p H E use of a cadmium sulfide crystal as -*• the mainspring of a h i g h s p e e d a u t o matic x-ray inspection device, a d e v e l o p ment of General Electric X-Ray Corp-, will o p e n a new field of crystal-electric e n g i neering, t h e company predicts. T h e c a d minum sulfide crystal w h e n excited w i t h x-radiation, releases t o r r e n t s of electrons t h a t can be used t o o p e r a t e various t y p e s of mechanisms. One a n area-for-area basis t h e crystals are over 1 million times m o r e sensitive to x-rays t h a n are ionization chambers commonly used to m e a s u r e xradiation, and they a r e over 1,000 times more sensitive t h a n photoelectric cells such as those used i n "electric-eyes/* Terming t h e development "a revolution-
CHEMICAL
C a d m i u m sulfide crys tals magnified 2 5 times ary discovery—one of t h e most challenging in t h e industrial x-ray field in t h e past 2 0 y e a r s , " G E believes t h e crystals m a y solve all sorts of inspection p r o b l e m s , and will a l l o w u n p r e c e d e n t e d s p e e d s . Crystals can b e grown in size from a fraction of a
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ENGINEERING
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