A peak elutes from an HPLC column 13.8 cm in length in 14.8 min. What would be the width at half-height of the peak (in seconds) if the plate height were 7.75 µm? W 1/2 4.1 W 1/2 Incorrect What would be the width at half-height of the peak (in seconds) if the plate height were 46.0 µm? 24.3 Incorrect S S

A peak elutes from an HPLC column 13.8 cm in length in 14.8 min. What would be the width at half-height of the peak (in seconds) if the plate height were 7.75 µm? W 1/2 4.1 W 1/2 Incorrect What would be the width at half-height of the peak (in seconds) if the plate height were 46.0 µm? 24.3 Incorrect S S

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter26: An Introduction To Chromatographic Separations

Section: Chapter Questions

Problem 26.10QAP

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Similar questions

A peak elutes from an HPLC column 13.8 cm in length in 14.8 min. What would be the width at half-height of the peak (in seconds) if the plate height were 7.75 µm? W 1/2 = What would be the width at half-height of the peak (in seconds) if the plate height were 46.0 μµm? W 1/2 = S S
A peak elutes from an HPLC column 17.4 cm in length in 11.4 min. What would be the width at half-height of the peak (in seconds) if the plate height were 4.66 µm? W1/2 What would be the width at half-height of the peak (in seconds) if the plate height were 42.0 µm? W 1/2 = S S
1. A compound has a molar absorptivity of 3.031 x 10° L cm1 mol1. If a 15.00 mm-length cell is used to hold the sample, and a transmittance of 19.53 % is measured, what is the molarity of the compound in solution?
Q4) (a) Explain how the components of a mixture are separated in gas chromatography. (b) An aqueous solution whose concentration is 0.00356 M was analyzed using spectrophotometer with a molar absorptivity of 412 cm-1 mol-1 L in a cell with a 2.00 cm pathlength. Calculate the absorbance and transmittance for the above solution. (c) Analyze the reasons why a dropping mercury electrode is better as compared to a conventional electrode.
A liquid sample was analyzed for Fe³+. A plot of absorbance (y-axis) vs. concentration (ppm; x-axis) of the external standards produced a calibration line with an equation y = 0.2256x -0.0903 (R² = 0.9973). The absorbance of the sample was 1.25. Determine the amount of Fe³+ in the sample (in ppm).
In the process of performing a spectrophotometric determination of Fe, an analyst prepares a calibration curve using a single-beam spectrometer, such as a Spec-20. After preparing the calibration curve, the analyst drops the cuvette used for the method blank and the standards. The analyst acquires a new cuvette, measures the absorbance of the sample, and determines the %w/w Fe in the sample. Will the change in cuvette lead to a determinate error in the analysis? Explain.
3. The lead in a swab sample, lead standards, together with a blank were made up in 5.00 mL volumetric flasks using 0.2 % HNO3. 20 μL aliquots of these solutions were injected into the spectrophotometer and the absorbance measured at 217 nm. The following results were obtained. lead / ppb Absorbance 0 0.0591 10.00 0.0858 50.00 0.1926 100.0 0.3260 150.0 0.4594 200.0 0.5929 Swab sample 0.3700 (a) Determine the amount of lead in the swab sample in μg.
An HPLC setup has an injection volume of 0.353 mL and a detector volume of 0.300 mL. The baseline width, Wobs, of a band eluting from the column at a flow rate of 1.45 ml/min is observed to be 35.6 s. Calculate the baseline width of the band, in seconds, if the column was the only source of broadening. Wcolumn= S
A peak elutes from an HPLC column 13.3 cm in length in 15.3 min. What would be the width at half-height of the peak (in seconds) if the plate height were 8.62 µm? wi/2 S What would be the width at half-height of the peak (in seconds) if the plate height were 43.0 µm? Wi/2 = S
What are the 5 important characteristics of spectrophotometric methods
The validation process comprises four main steps that are : hardware validation, software validation, method validation and system suitability. To evaluate a spectrophotometer’s accuracy by measuring absorbance, a solution of 60.06 mg/L K2Cr2O7 in 0.0050M H2SO4 was carefully prepared together with a 0.0050 M H2SO4 as a reagent blank. If the spectrometer’s signal is properly calibrated, it has been reported that this solution should provide an absorbance of 0.640 +- 0.010 at wavelength 350 nm. Which one of the validations mentioned above had been involved in this process? Explain your choice
Q5. Two methods were used to measure fluorescence lifetime of a dye. The average result for Method 1 is = 1.382 ns with a standard deviation of s1 = 0.039 and n1= 7. The average result for Method 2 is = 1.346 ns with a standard deviation of s2 = 0.015 and n2= 5. Is there a difference between the two methods at the 95% confidence level using F test?