*26-14 The following data are for a liquid chromatographic column Length of packing Flow rate 24.7 cm 0.313 mL/min Vt Vs 1.37 mL 0.164 mL A chromatogram of a mixture of species A, B, C, and D provided the following data: Retention Width of Peak Time, min Base (W), min Nonretained 3.1 6.2 0.49 13.3 1.07 15.7 1.32 D 21.6 1.72 Calculate (a) the number of plates from each peak. (b) the mean and the standard deviation for N. (c) the plate height for the column. * 26-15 From the data in Problem 26-14, calculate for A, B, C, and D (a) the retention factor. (b) the distribution constant. * 26-16 From the data in Problem 26-14, calculate for species B and C (a) the resolution. (b) the selectivity factor a. (c) the length of column necessary to separate the two species with a resolution of 2.5. (d) the time required to separate the two species on the column in part (c).

26-14 The following data are for a liquid chromatographic column Length of packing Flow rate 24.7 cm 0.313 mL/min Vt Vs 1.37 mL 0.164 mL A chromatogram of a mixture of species A, B, C, and D provided the following data: Retention Width of Peak Time, min Base (W), min Nonretained 3.1 6.2 0.49 13.3 1.07 15.7 1.32 D 21.6 1.72 Calculate (a) the number of plates from each peak. (b) the mean and the standard deviation for N. (c) the plate height for the column. 26-15 From the data in Problem 26-14, calculate for A, B, C, and D (a) the retention factor. (b) the distribution constant. * 26-16 From the data in Problem 26-14, calculate for species B and C (a) the resolution. (b) the selectivity factor a. (c) the length of column necessary to separate the two species with a resolution of 2.5. (d) the time required to separate the two species on the column in part (c).

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter15: Electrophoresis And Other Separation Methods

Section: Chapter Questions

Problem 5P

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The following data are for a liquid chromatographic column: column length 24.7 cm volume of the mobile phase, Vm 1.37 mL volume of the stationery phase, Vs 0.164 mL A chromatogram of a mixture of species A, B, C and D provided the following data: Calculate the plate height in milimeters (mm) for species A. Retention Widht of Peak Time, min Base (W), min Nonretained 3.1 - A 5.4 0.41 B 13.3 1.07 14.1 1.16 D 21.6 1.72
A method of quantitative determination of the concentration of constituentsof a sample analyzed by gas chromatography is area normalization. Thiscomplete elution of all sample constituents is required. Thearea of each peak is measured and corrected for the detector response to the diffe- renteseluatos. This correction involves dividing the area by an empiricalcorrection factorDetermined. The concen ration of the analyte is found from the ratio between itscorrected and the total corrected area of all peaks. For a chromatogram containing threerelative areas were determined as 16.4; 45,2; and 30.2, in the order ofincreased retention time. Calculate the percentage of each compound if therelative responses from the detector are 0.65, 0.73 and 0.85, respectively.
2
The following data were obtained by gas-liquid chromatography on a 4.0 m packed column: Compound tr (min) Wb (min) Air 1.4 X 10.0 0.85 Y 10.9 0.94 13.4 1.26 How many effective plates are required in resolving X and Y (RSxy) to achieve a resolution like separation between Y and Z (RSrz) ?
Researchers 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.
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From the data calculate : a) the number of plates from each peak b) the mean and the standard deviation for N c) the plate height for the column
hree components in a mixture have varying distribution constants between the mobile phase and the stationary phass One of the components has a very low distribution constant, Would this component likely elute first or last and how would you design an experiment or modify the components of the separation to make it perform in the opposite manner?
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