REPORT OF ANALYSTS gen peroxide in aqueous systems. U p to t h e present, n o one h a s reported radiation effects o n a n y of t h e electrometric techniques, with t h e possible exception of effects on glass electrodes. There is some fragmentary a n d contra dictory evidence in t h e l a t t e r case which needs clarification. T h e ultimate solution t o t h e problem of analyses in radiochemical processing plants a n d even in reactors will prob ably be t h e development of in-line analytical instrumentation, a n d this approach is being followed a t several A E C installations. However, in t h e development programs such as we en counter a t O R N L , these techniques are less applicable, because process condi tions are varied frequently a n d develop m e n t work sometimes requires more d a t a t h a n are given b y instrumentation.
NEW INSTRUMENT MEASURES REFRACTIVE INDEX DIFFERENCES TO AN ACCURACY OF
0.00002 Employs the Rayleigh Interference method of refractometry to provide extremely high sensitivity. Sam ples as small in size as 1.6 ml may be used. Instrument permits per formance of such operations as: (1) Concentration of extremely di lute solutions, (2) Dispersion of solutes, and (3) Measurement of refractive index differences for molecular weight determina tions by light scattering.
Summary T h e analytical chemist in t h e nuclear field is interested in analytical radiochemistry, t h e identification a n d meas u r e m e n t of radioactive species present, and t h e chemical analysis of highly radioactive samples. I n solving t h e wide variety of problems encountered, the analyst utilizes nearly all recognized techniques a n d develops new ones. Classical radiochemical techniques arc satisfactory in most respects, except time required. Advances in instru mentation and automation and methods which allow use of small samples are pro viding new approaches. In-line analy tical i n s t r u m e n t a t i o n is one answer t o m a n y of t h e problems. Developments in t h e nuclear energy field are resulting in materials of m u c h greater activity t h a n those formerly encountered. This in t u r n requires greater use of remote control analyses. Challenging problems t o be solved include t h e determination of t h e extent to which radiation m a y interfere with analytical determinations. There m a y be effects on b o t h reagents a n d a p p a r a t u s used.
AMINCO-JONNARD
Cat. N o . 10-251 Assembly—Includes a monoc ular microscope especially fitted for refractometry; an Aminco-Jonnard Refractometer complete with one cell, as illustrated above; and a fitted wooden carrying case $742
Literature Cited (1) Coryell, C. D., Sugarman, N., Radio chemical Studies. The Fission Prod ucts McGraw-Hill, New York, 1951. (2) Dvkes, F . W., Fletcher, R. D., Turk, E. H., Rein, J. E., Shank, R. C ,
Cat. No. 10-258 Illuminator for the microscope Cnot shown ) furnished with filter holder, but without filters. Operates on 115 volts, 60cycle a.c $63
ANAL. C H E M . 28, 1084(1956).
(3) Frederick, E . J., Nucleonics 12, 36 (1954). (4) Kelley, M. T., Fisher, D . J., and staff, Fifth H o t Laboratories and Equip ment Conference, March, 1957 (to be published in Proceedings of 1957 Nuclear Congress, Pergamon Press). (5) Reynolds, S. Α., Rec. Chem. Progr. 16, 99(1955). ((>) Shank, R. C , Rein, J. E., Huff, G. Α., Dykes, F . W., Tenth Summer Symposium, Division of Analytical Chemistry, ACS, June 1957; ANAL.
AMERICAN INSTRUMENT CO., INC. 8030
GEORGIA
A V E . , SILVER
SPRING,
MARYLAND
CHEM., in press For further Information, circle number 27 A on Readers' Service Card, page 83 A VOL. 2 9 , N O . 1 1 , NOVEMBER 1 9 5 7
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27 A
