Principles of Instrumental Analysis
7th Edition
ISBN: 9781305577213
Author: Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Question
thumb_up100%
Chapter 26, Problem 26.14QAP
Interpretation Introduction
(a)
Interpretation:
Number of plates from each plate should be calculated.
Concept introduction:
Number of theoretical plates given by following equation;
N = number of plates
tR = retention time
W = width of peak base
Interpretation Introduction
(b)
Interpretation:
Mean and standard deviation for the N should be calculated.
Concept introduction:
Mean =
Standard deviation will give how the values deviate from mean value of N.
Interpretation Introduction
(c)
Interpretation:
Plate height of the column should be determined.
Concept introduction:
N = plate count
L = length of the packing (cm)
H = height of the column
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
4.Consider the peaks for pentafluorobenzene and benzene in the gas chromatogram shown here. The elution time for unretained solute is 1.06 min. The open tubular column is 30.0 m in length and 0.530 mm in diameter, with a layer of stationary phase 3.0 μm thick on the inner wall.
a) Measruing the width, w, at the baseline on the chromatogram, find the number of plates for these two compounds
b) Use your answer to (a) to find the resolution between the two peaks
c) Using the number of plates N=sqrtN1*N2 with the values from (a) calcuate what the resolution should be and compare your answer with the measured resolution in b
In stationary chromatography, the distribution (K) is the main criterion for the division of species in the sample between the two functions of the system, which factors depend on
The results in the table below were obtained from the analyses of Mg2+ content in an orange
juice sample using a flame-AAS. Based on these results answer the following questions:
(i)
(ii)
Replicate
1
2
3
4
Mg²+(ppm)
7.08
7.21
7.12
7.09
Calculate the mean, standard deviation and coefficient of variation (or %RSD) for the
results obtained.
If the certified value of the Mg2+ content of the apple juice sample is 7.45 ppm. What
is the percentage of recovery for this analysis?
Chapter 26 Solutions
Principles of Instrumental Analysis
Ch. 26 - Prob. 26.1QAPCh. 26 - Prob. 26.2QAPCh. 26 - Prob. 26.3QAPCh. 26 - Prob. 26.4QAPCh. 26 - Prob. 26.5QAPCh. 26 - Prob. 26.6QAPCh. 26 - Prob. 26.7QAPCh. 26 - Prob. 26.8QAPCh. 26 - Prob. 26.9QAPCh. 26 - Prob. 26.10QAP
Ch. 26 - Prob. 26.11QAPCh. 26 - Prob. 26.12QAPCh. 26 - Prob. 26.13QAPCh. 26 - Prob. 26.14QAPCh. 26 - Prob. 26.15QAPCh. 26 - Prob. 26.16QAPCh. 26 - From the data in Problem 26-14, calculate for...Ch. 26 - Prob. 26.18QAPCh. 26 - Prob. 26.19QAPCh. 26 - Prob. 26.20QAPCh. 26 - Prob. 26.21QAPCh. 26 - Prob. 26.22QAPCh. 26 - Prob. 26.23QAP
Knowledge Booster
Similar questions
- (a) In High Performance Liquid Chromatography (HPLC), the separation method is by partition of the solute (analyte) between the mobile phase and the stationary phase. Explain how this leads to separation of analyte mixtures; (b) Describe the structure and materials use in a typical column used for HPLC. Thereby explain why high pressures have to be used in HPLC; (c) Discuss how the need for high pressures also imposes requirements on the injector;arrow_forwardReplicate tests showed the following lead content results of a blood sample: 0.752, 0.756, 0.752, 0.751, and 0.760 ppm Pb. Calculate the (a) the mean (b) the standard deviation (c) the variance (d) the relative standard deviation in parts per thousand, (e) the coefficient of variation, and (f) the spread.arrow_forwardThe following results were obtained for the determination of calcium in a NIST limestone sample: %CaO = 50.33, 50.22, 50.36, 50.21, and 50.44. Five gross samples were then obtained for a carload of limestone. The average %CaO values for the gross samples were found to be 49.53, 50.12, 49.60, 49.87, and 50.49. Calculate the relative standard deviation associated with the sampling steparrow_forward
- One method for the quantitative determination of the concentration of constituents in a sample analyzed by gas chromatography is area normalization. Here, complete elution of all the sample constituents is necessary. The area of each peak is then measured and corrected for differences in detector response to the different eluates. This correction involves dividing the area by an empirically determined correction factor. The concentration of the analyte is found from the ratio of its corrected area to the total corrected area of all peaks. For a chromatogram containing three peaks, the relative areas were found to be 16.4, 45.2 and 30.2, in order of increasing retention time. Calculate the percentage of each compound if the relative detector responses were 0.60, 0.78 and 0.88, respectively.arrow_forwardResearchers used gas chromatography to determine the % v/v methyl salicylate in rubbing alcohol [Van Atta, R. E.; Van Atta, R. L. J. Chem. Educ. 1980, 57, 230-231]. A set of standard additions was prepared by transferring 20.00 mL of rubbing alcohol to separate 25 - mL volumetric flasks and pipeting 0.00 mL, 0.20 mL, and 0.50 mL of methyl salicylate to the flasks. All three flasks were diluted to volume using isopropanol. Analysis of the three samples gave peak heights for methyl salicylate of 57.00 mm, 88.5 mm, and 132.5 mm, respectively. Determine the % v/v methyl salicylate in the rubbing alcohol.arrow_forwardThe following results were obtained for the determination of calcium in a NIST limestone sample: % CaO = 50.32, 50.22, 50.40, 50.21, and 50.44. Five gross samples were then obtained for a carload of limestone. The average percent CaO values for the gross samples were found to be 49.47, 50.10, 49.58, 49.76, and 50.49. Calculate the relative standard deviation associated with the sampling step. Relative standard deviation =arrow_forward
- 3. Seven analyses for the phosphorus content of a fertilizer resulted in 16.2, 17.5, 15.4, 15.9, 16.8, 16.3, and 17.1%. Find (a) the standard deviation, s, , and (b) the 95% confidence interval for the true value, H. 4. The following five values were obtained for the wt % of an organic acid in a sample: 30.3, 31.1, 32.6, 36.7, 28.9. Determine if the value of 36.7 may be rejected at the 90% (two-tailed) confidence level. 5. The concentration of a NaOH solution is determined in a single experiment by titrating a weighed sample of pure, dried KHP (MW = 204.229) with the NaOH. The data are: Weight of KHP = (11.6723 + 0.0001) - (10.8364 ±0.0001) g Volume NaOH = (32.68 + 0.02) - (1.24 + 0.02) mL Where the standard deviations are o, values. (a) What is the molarity of the NaOH? (b) Based on the propagation-of-error formula, what is the standard deviation of the molarity,oM ?arrow_forwardAnalysis of several plant-food preparations for potassium ion yielded the following data: Sample Percent K+ 1 3.90, 3.96, 4.16, 3.96 2 4.48, 4.65, 4.68, 4.42 Find the mean ; standard deviation variance and RSD for each sample.arrow_forwardA standard sample contains 15.0 mM of analyte and 25.0 mM of internal standard. The analysis of the standard sample gives peak areas for the analyte and internal standard of 1.782 and 3.539, respectively, in a chromatography analysis. Then sufficient internal standard is added to a sample to make its concentration 10.0 mM. The analysis of this new sample yields peak areas for the analyte and internal standard of 0.894 and 2.981, respectively. Name the calibration method and report the analyte's concentration in the new sample. (e)arrow_forward
- Pls. show the full solutionarrow_forwardA volume of 250 ml of a 0.05 M solution of a reagent of formula weight (relative molecular mass) 40 was made up, the weighing being done by difference. The standard deviation of each weighing was 0.0001 g. 1 (a) What were the standard deviation and relative standard deviation of the weight of reagent used?arrow_forwardThe pH of water samples taken from Iligan Bay was determined. Calculate the pooled estimate of the standard deviation for the analysis, based from the following columns of data: Site No. of Samples measured pH Mean pH Sum of Squares of Deviation from the Mean 1 4 8.02, 8.09, 7.95, 7.98 8.01 0.0110 2 3 7.50, 7.65, 7.49 7.55 0.0161 3 3 8.25, 8.29, 8.20 8.25 0.0041arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning