CORRECTIONS Tube Cracker for Opening Glass-Sealed Ampoules under Vacuum
In this article by D. J. Des Marais and J. M. Hayes, Anal. Chem., 48, 1651 (1976) the catalog numbers for two commercially-available vacuum fittings listed in the caption of Figure 1are incorrect. The correct catalog number for Fitting ( B ) is SS-6-UT-6;the correct number for Fitting (G) is SS6-UT-6-4.
An improved Fabricatlon Technique for Alkali Flame Ionization Detector Salt Tips
In this article by B. M. Johnson, B. D. Kaiman, and R. W. Lambrecht, Anal. Chem., 48,1271 (1976), a calculation error was made. The last sentence of the text should read “. . . and demonstrate an N:C selectivity of 1:1470 for this pair of compounds.” In addition, Dr. R. Greenhalgh (Chemistry and Biology Research Institute, Ottawa, Ontario, Canada) has pointed out that the N:C selectivity based on moles of N:moles of C is 1: 3780. This figure may be a more useful index of selectivity for other investigators.
= ( k T / h )eAS’*IR e-AH‘*IRT
(12)
Also Equation 15 has shown, incorrectly, the rate constant for loss of atomic vapor as k d . The correct rate constant is k ~ . The corrected equation is given below:
It has been stated, incorrectly in the 6th line below Equation 16 on p 1795, that “a slope of -(Ea AH0)2.3R”will be obtained. The correct slope is -(Ea AH0)/2.3R. In the 4th line above the Experimental section on p 1796, the temperature-dependent parameters ( kA, k d , a,, and T ) have been listed. This list should read ( k A , k ~a,,, and T). The coordinate for Sn(,) (74 kcal mol-l, 1560 K) plotted in Figure 9 has not been labeled. Figure 9, labeled also for Sn(,), is shown below.
+
+
1501
/
Studies on the Mechanism of Atom Formation in Graphite Furnace Atomic Absorption Spectrometry
In this article by R. E. Sturgeon, C. L. Chakrabarti, and C. H. Langford, Anal. Chem., 48,1792 (1976), a typographical error in Equation 12 has shown a negative exponent for the entropy of activation, instead of a positive exponent. The corrected equation is given below:
192
ANALYTICAL CHEMISTRY, VOL. 49, NO. 1, JANUARY 1977
0
500
1000 1100 APPEARANCE TEMPERATURE, K
em0
23001
