Notes and Corrections for Skoog, Holler, and Nieman, "Instrumental Analysis, 5th edition.

These corrections apply to the First Printing by Saunders College Publishing. Some errors have been corrected in later printings. Email comments and corrections to dpoe@d.umn.edu.

Notes and Corrections to Text

Chapter	Page	Statement in Text	Correction
5	108	Equations 5-10 and 5-11, which deal with signal-to-noise ratio, are questioned.	See lecture notes on Signals and Noise, S/N and Multiple Measurements
6	126	At bottom of left column nvac = 1.00027 nair	The notation may be misleading since it is inconsistent with the preceding usage. Rewrite as (nx)vac = 1.00027 (nx)air where (nx)vac, (nx)air are the indices of refraction of substance x relative to a vacuum, and air, respectively. An average value for the index of refraction of air relative to a vacuum is 1.00027.
9	211	In reference to Figure 9-7, "The sample peak on the far right indicates a lead concentration of about 0.1 ug/mL of juice."	"The sample peak on the far right indicates a lead concentration of about 0.05 ug/mL of juice."
27	702	Section 27A-1 contains some fundamental errors. To avoid confusion, I advise you not to read this section. See the alternative listed at right.	Edited version section 27A-1 Retention Volumes
27	705	Third paragraph in 27-B3 Column Configurations... "Roughly, a temperature equal to or slightly above the average boiling point of sample results in a reasonable elution time."	In general, the column temperature should be somewhere between the dew point (where the vapor pressure is equal to the equilibrium vapor pressure) and the boiling point of a sample component. The column temperature should be significantly below the boiling point of the sample components, by perhaps 20 C or so, to obtain adequate retention and resolution. If the column temperature is at or above the boiling point of the sample, little or no retention will occur.

Answers to Problems

Question	Answer
5-8	For part b, n = 4. (SHN give n = 28)
9-16	0.056 ppm Pb, or about 0.06 ppm.
9-22	For part e, standard deviation is 0.19 ppm (SHN give 0.22). To get the 95% confidence interval, use t = 3.18 for N-2 = 3 degrees of freedom. Result is conc. of Cr = 28.0 +/- 0.61 ppm Cr.
15-6	Some printings have errors. The correct values are b) I = 22.43c + 0.031 c) sm = 0.45, sb = 0.23 d) 0.541 e) (sc)r = 2.6% f) (sc)r = 1.7%
15-8	Not enough information provided to completed parts e and f
15-9	Some printings have an error. Correct answer is 2.83 x 10^-5 M
20-6	The question should specify Example 20-4 on page 515, not Example 20-2 on page 503.
26-25	Some printings of the text have incorrect answers. Data given in problem are Peak Areas: 27.6, 32.4, 47.1, 40.6, 27.3; Detector Response: 0.70, 0.72, 0.75, 0.73, 0.78. The component percentages are: 16.6, 18.9, 26.4, 23.4, 14.7.
27-21	Average flow rate: 15.4 mL/min Corrected retention volumes air: 4.61 mL methyl acetate: 30.4 mL methyl propionate: 63.9 mL methyl butyrate: 121.9 mL Specific retention volumes methyl acetate: 13.4 mL/g methyl propionate: 30.9 mL/g methyl butyrate: 61.0 mL/ Distribution constants (ordered as above) 18.8 43.2 85.4 For methyl n-hexanoate Corrected retention volume: 550.8 mL 35.8 min Answers given for 27-22 are correct.