Table I. Relative Concentrations Obtained for Some Olefinic Compound Mixtures 1 Taken
Acrylonitrile Divinylsulfone Methyl acrylate cis-4-Methyl-2-pentene
15.7 49.8 34.5
...
trans-4-Methyl-2-pentene
2
Found(1)a Found(2)a
18.0 48.1 33.9
...
...
15.7 48.3 35.9
... ...
Found(1)
Found(2)
Taken
Found(1)
61.9
... ...
61.9
63.0
27.6
28.1
... ...
...
28.7
... ...
9.4
10.5
8.9
38.7 16.4 44.9
38.5 15.8 45.8
41.6 15.6 42.8
...
...
4
Taken
Acrylonitrile Divinylsulfone Methyl acrylate cis-4-Methyl-2-pentene trans-4-Methyl-2-pentene a See text.
... ...
45.0 55.0
3
Taken
... ...
Found(2)
6
5
Found(1)
Found(2)
Taken
Found(1)
Found(2)
Taken
Found(1)
Found(2)
... ...
... ... ...
20.4 44.7 20.6
22.2 44.9 20.2
19.8 48.7 19.1
46.9 53.1
47.8 52.2
14.2
12.7
12.4
18.4 22.3 8.0 21.7 29.5
19.5 25.3 7.9 19.9 27.4
16.7 24.2 9.2 19.6 30.3
methyl-2-pentene. In this case, the signal heights measured from the chart are less accurate and contain some arbitrariness depending on the way of measurement. However, even if a slight superposition of the signals such as shown in Figure 1 is present, any conventional simple method for dividing the superposed band into single lines, e.g., even by visual dividing, is sufficient to give the signal height input data which provide the desired results within the experimental errors. It is an important feature of the present method that the slight frequency deviation of the observed spectrum from the calculated one can be offset by use of the broadening function. It is preferable, however, that the chemical shift values of the components in the mixture are corrected after one cycle calculation, because PMR signals of the olefinic compounds predominantly consist of well-resolved sharp lines, and a relatively large concentration dependence of the chemical shift is observed. The present method has
...
...
...
such a version, and this refinement improves the results to some extent. As described above, for the olefinic compounds which show a number of well-resolved sharp lines, only the position and the height of each PMR signal were used as input data to give the results comparable to those obtained when using the whole observed spectrum in a digitized form. Therefore, it is unnecessary to have any facility, e.g., a paper punch, that transforms the observed spectrum into a digitized form. LITERATURE C I T E D (1) F. Kasler. "Quantative Analysis by NMR Spectroscopy", Academic Press, New York, N.Y., 1973. (2) 0. Yamamoto and M. Yanagisawa, Anal. Cbem., 47, 697 (1975).
RECEIVEDfor review July 28, 1975. Accepted November 17, 1975.
Determination of Parts-per-Million Cesium in Simulated Nuclear Waste with the Cesium-Selective Electrode Elizabeth W. Baumann Savannah River Laboratory, E. 1. du Pont de Nemours and Company, Aiken,
A cesium-selective electrode with a liquid membrane of cesium tetraphenylboron dissolved in 4-ethylnitrobenzene gave near-Nernstlan response (slope of 52 mV per decade) M Cs+. Major interferences were from l o - ' to M Cs+, the pH range was NH4+, Ag+, and Hg2+. At 6-8. For the application, cesium was first extracted from high sodium, strongly alkaline solutions with 1 M 4-secbutyl-2( a-methylbenzyl)phenol (BAMBP) in cyclohexane. Electrode measurements were then made in 0.01 M TrisHCI buffer solution at pH 7.1. By the standard addition M can be demethod, cesium concentrations 2 5 X termined with relative standard deviation and relative bias
