Table V.
the rare earths) which may feasibly be determined with the use of a n iron hollow cathode. The iron hollow cathode as a source of this type can be used very effectively as a n intermediate sensitivity system on, at the least, the elements studied in this paper.
Interference of Absorption by Iron
Increase or decrease in absorption on 100 p.p.m., % Concn. Fe Cuaaai cum 10 0 0 50 +3.9 0 100 +4.5 0 500 +6.4 -1.5 denotes an increase in absorption. denotes a decrease in absorption.
Ni 0 -3.4 -7.6 -10.2
+-
Be Cu Ga Ge In Pb hlg Mn Hg Mo Ni Re Sr
F
Wavelength, A. Feline 3961.53 3961.14 2311.47 2311.29 2311.22 2312.03 5535.55 5535.41 3247.54 3247.28 2874.24 2874.17 2651.57 2651.71 3039.36 3039.32 2614.18 2614.49 2852.13 2852.13 2794.82 2794.70 2536.82 2536.52 2864.11 3863.74 3524.54 3524.24 3459.92 3460.47 4607.65 4607.33 3034.12 3034.54 3184.90 3185.40
Mg 0 0 +16.6 +58.3
LITERATURE CITED
Table VI. Elements Which M a y Feasibly Be Determined Using an Fe Hollow Cathode
Element A1 Sb
Mn 0 0 0 0
The half band widths do not change appreciably with concentration. Therefore, a n y absorbing point may be used with no adverse effects in the calibration curves. Deviation from Beer's law occurs as would be expected at high concentrations. Interference from Iron. T h e interference from iron is given in Table V. T h e interferences were checked on a 100 P.P.m. absorbing metal sample and t h e d a t a are in percentage decrease or increase from t h a t concentration. Essentially no significant effect is seen except in t h e case of Mg. From the above data, the elements that overlap a n iron line should show absorption. Unfortunately, the sensitivities of the elements cannot be estimated from the intensity of the iron lines, since the band widths and amount of overlap are very important factors. Table V I gives the elements (excluding
Intensity (2) Fe Line 25 35 20 15 50 200 300 60 20 40 150 50 10 60 60 80 50 70 200
Correction:
(1) Belchev, B., Beleva, St., Dancheva, R., Rubodobiv. Met. 7, 18 (1964). (2) Elwell, W. T., Gidley, J. A. F., "Atomic Absorption Spectrophotometrv." Macmillan. New York. 1962. (3) Fassel, V. A,, Llossotti, 1'. 'G., Grossman, W. E. L., Kiniseley, R. D., Spectrochim. Acta, in press. (4) Frank, C. W., Schrenk, W. G., Meloan, C. E., ANAL. CHEM. 38. in press. (5) "Handbook of Chemistry and Chemistrv Physics," 39th Ed., p. 2541, Chemical Rubber Co., Cleveland, 1958. (6) Ivanov, N. P., Kozyreva, N. A,, Zh. Analit. Khim., 19, 1266 (1964). (7) Sebens, C., Vollmer, Vollmer, J., Slavin, W., Perkin-Elmer Atomic Absorwtion ivewsNewsletter 3, 165 (1964). (8) Slavin, W., Sprague, S., Manning, D. W., Perkin-Elmer Atomic Absorption Newsletter 18, 2 (1964). RECEIVED for review December 13, 1965. Accepted February 7, 1966. Fifth National Meeting of the Society for Applied Spectroscopy, Chicago, Ill., June 1966. In partial fulfillment for the Ph.D. degree in chemistry for C. W. F. The authors thank the Kansas State University Bureau of General Research and the Sponsored Research Overhead Fund for financial support.
Mass Spectra of Isocyanates
I n this article by John M. R u t h and Roger J. Philippe [ASAL. CHEW.38, 720 (1966)l on page 722, second part of Table I, the numerical column headings are, in general, incorrectly aligned with the columns. The proper alignment should be as indicated below.
Table
(I)@ (2)"
(3)"
82 83 84 84.5 85 86 87 -. 88 89 90 91 92 95 96 97 98 99
(5)s
17
1
17 1
15 1
Time-of-Flight Mass Spectra (continued)
(6)O 2 11
Relative intensity, yo (7)5 (9)' 1 2 3 3 9 0.4 9 4 23 2 0.3
10 2 0.5
(IO)= 23 6 1
(ll)a
0.4
0.4 1 1
6
74 10 0.3
0.2 1
1 1
4
(12)'
0.8 1 2 2 9 8 21 2
0.9 1 1 1 3 4 20 2
0.8 0.4 0.1 3 5 91 62 12
0.3 2 0.3 0.1 2 3 42 19 5
3 11 b
101 102 103 104 105 106
ANALYTICAL CHEMISTRY
(13P
(14)a
0.3
0.7
100
1008
(4)"
I.
(15)"
15 0.7 1 1 1 3 4 22 3
0.3 0.3 0.1 2 4 35 23 6
7 13 11 5 3 0.7
0.3 2 2 2 1 1
0.4
