For the tin-base solder alloy, Stokes’ law calculations showed that solidified particles with a maximum diameter of 12 to 14 microns should be transported to the plasma by the 2 liters/minute argon fiow. These predictions were confirmed by direct measurement of particle size distribution. The majority of particles were 12 microns or less in diameter, and the largest particles observed were in the 14- to 15-micron diameter range. Undoubtedly, larger aerosol particles were produced but were not transported to the plasma by the gas flow employed. The flow of powdered aerosol to the plasma was not determined, but was estimated to be in the 1-10 mg/minute range. With appropriate adaptations of this or other ultrasonic nebulization techniques, continuous composition monitoring of molten metal in either static or flowing systems is now in the realm of possibility. Other materials in liquid form, such as
oils, paints, and process liquors, should be equally amenable to continuous analysis by this technique. ACKNOWLEDGMENT The authors thank Bronwill Scientific for the loan of their Biosonik-I1 Ultrasonic Probe, C. C. Hill for constructing the needed glassware, R. H. Wendt for performing preliminary studies on metal nebulization, and W. B. Barnett for his assistance in operating the induction coupled plasma. VELMER A. FASSEL GEORGE W. DICKINSON Institute for Atomic Research and Department of Chemistry Iowa State University Ames, Iowa RECEIVED for review May 29, 1967. Accepted October 30, 1967.
The Effect of Static Magnetic Field on Polarography SIR: Besides theoretical analysis of the Hall effect of magnetic field on the electrolytic ions in solution ( I ) , a few measurements of this effect have been reported (2, 3). However, no experiment has been done with respect to the effect of magnetic field on polarography. Antweiler tried but failed to observe this effect (4). This effect was examined with the use of the dropping mercury electrode polarograph, where magnetic field, H , ranging from 0 to 18,000 oersteds was applied perpendicularly to the electrodes. No effect was observed in the recorded polarogram with respect to the intensity of the residual current, half-wave potential, and the diffusion current, but a sizable effect was observed in the current intensities of the maximum waves of the first and the second kinds, .,i and L,, 2nd. Namely, when H is applied, ,i is reduced. Figure 1 reproduces the results of measurements in typical cases. (1) H. L. Friedman, J . Phys. Chem., 69,2617 (1965). (2) D. Laforgue-Kantzer,Electrochim. Acta, 10,585 (1965). (3) N. I. Pekhteleva and A. G. Smilnov, M a g n h . Gidrodinam., Akad. Nauk. Larv., SSR,1965(2),89; C . A . , 64,279h (1966). (4) H. Antweiler, 2.Ekkrrockem., 44,836 (1938).
Table I. Chemical Systems Whose Polarograms Show (a) an Effect of Magnetic Field, and (b) No Effect of Magnetic Field Depolarizer Maxima (a) MnCh (I1 0) 2nd max NiCh (I1 0) 2nd max (11 0) 2nd max [CO(”3)61Ch 2nd max [Co(NH3)jCl]Clz (I1 + 0) cos04 (11 0) 2nd max 2nd max Cd(N03)~ (I1 0) FeC12 (I1 + 0) 2nd max AlC13 (111 0) 2nd max (111 0) 1st max Cr(NOd3 cuso* (I1 + 0) 1st max 1st max (NH&M070z4 (VI --c V) (1 0) 1st & 2nd TlCl (1 0) no maxima (b) HCI (111 11) no maxima [Fe(CN)J3(IV + ?) no maxima Th(SOn)z (111 0) no maxima Bi(NO& uozso4 (VI V) no maxima no maxima [CO(NH3)8]C13 (111 + 11) no maxima [Co(NH,)CI]Clz (111 + 11)
-------
0 Gauss
Ld’
---J
-1
N
7000 Gauss
AC
Pdarcgram -1.3V
1,
hd
-1.34
-’
D C Polarogram
L
Figure 1. Effect of magnetic field on polarogram Mn(I1) 0.5mM KCI 1M Table I shows the classification of chemical systems which do or do not show this magnetic field effect. This effect becomes unobservable even with the systems cited as (a) in Table I, when the concentration of the supporting electrolyte is much reduced. Surface active reagents such as polyacrylamide and gelatin suppress this effect linearly with their concentrations. Just as in the general case with no values do not show the root square magnetic field, the ,i dependence on the mercury reservoir height in magnetic field. The effect cited above will be useful for the elucidation of the mechanism of the oxidation and the reduction at the sucface layers of mercury electrode, and its application can be pursued. Further investigation is in progress. SHIZUOFUJIWARA HIROKIHARAGUCHI YOSHIOUMEZAWA Department of Chemistry Faculty of Science The University of Tokyo Hongo, Bunkyoku, Tokyo Japan RECEIVED for review August 18, 1967. Accepted September 25,1967. VOL. 40, NO. 1, JANUARY 1968
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