(a)
Interpretation:
In order to obtain desired resolution of 1.5, the number of plates should be calculated.
Concept introduction:
The resolution can be calculated as follows:
(b)
Interpretation:
Height of the column should be calculated.
Concept introduction:
The plate height can be calculated as follows:
(c)
Interpretation:
Retention time of the methylcyclohexene should be calculated.
Concept introduction:
Retention time is directly proportional to the resolution. Therefore, following equation can be used.
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Chapter 26 Solutions
Principles of Instrumental Analysis
- 13. Electrospray time-of-flight mass spectrometry was used to analyze the eluate from a high-performance liquid chromatography separation. The mass spectrum of one chromatographic peak, containing a protein of unknown molecular mass, displays MH peaks at m/z = 5 654.208, 5 277.326, 4 947.590, 4 656.613, 4 397.990, and 4 166.576. Find the average molecular mass (M) of the neutral protein and its standard deviation.arrow_forwardSPECTROPHOTOMETRY 1.) Slope of regression line or Molar absorptivity (µM -1cm-1) is 0.0253 and absorbance of unknown solution is 0.131. What is the concentration of the unknown solution (µM )?arrow_forwardIn molecular exclusion (size exclusion) chromatography, the molecules have the longest retention times. a) the larger molecules b) the smaller moleculesarrow_forward
- 2-pentanone has a retention index of 987 on a poly(ethylene glycol) column (also called Carbowax). (a) Between which two straight-chain hydrocarbons is 2-pentanone eluted? (b) An unretained solute is eluted from a certain column in 1.80 min. Decane (C10H22) is eluted in 15.63 min and undecane (C11H24) is eluted in 17.22 min. What is the retention time of a compound whose retention index is 1 050?arrow_forward1) Study the chromatograph (below) of a mixture of Compounds A and B, run on the GCs in the teaching labs at CU Boulder. Compound A has the shorter retention time. STAAT 61 1.11 227 RT TYPE AREA XXXX XXXX XXXX AREAS 0.009 55874 44.117 ARIHT 0.61 XX XX XX 1.11 2.27 XX XX XX TOTAL AREA=XX MUL FACTOR=XX 1. What is the retention time of compound A? Compound B? 2. Which compound is present in a larger amount? 3. Which compound has the lower boiling point? 4. What would happen to the retention times of compounds A and B if the column temperature were raised? 5. You suspect that compound B is octane. What can you do to provide supporting evidence for this hypothesis?arrow_forwardIn a HPLC separation of two compounds, A and B, the retention times observed are 3.5 min. for A and 4.5 min. for B on a 15 cm column. The retention time for the mobile phase is 1.0 min. The peak widths (at the base) for A and B are 0.5 and 0.7 min respectively. Calculate the following: (i) The capacity factor of A and B. (ii) The peak resolution. (iii) The average number of theoretical plates in the columnarrow_forward
- A peak with a retention time of 10 minutes has a width at half-height of 7.6 s neighboring peak is eluted 15 s later with W½ = 7.5 s. (4) Find out the resolution for these two components. (a) (b) Is this resolution value good for quantitative analysis, why? (c) What difference in retention times is required for an adequate resolution of 1.5?arrow_forward(ii) What is the unadjusted relative retention for components A and B?arrow_forwardWhich compound has a retention time of 1.5 minutesarrow_forward
- Substance A and B were found to have retention times of 16.40 and 17.63 min. respectively, on a 30cm HPLC column. An unretained species passed through the column in 1.30 min. The peak widths at base for A and B were 1.11 and 1.21 min, respectively. Calculate the a.) Column resolution b.) the average nbumber of plates in the column and the plate height.arrow_forwardFerritin (molecular mass 450 000), transferrin (molecular mass 80 000), and ferric citrate were separated by size exclusion chromatography on Bio-Gel P-300. The column had a length of 37 cm and a 1.5-cm diameter. Eluate fractions of 0.65 mL were collected. The maximum of each peak came at the following fractions: ferritin, 22; transferrin, 32; and ferric citrate, 84. (That is, the ferritin peak came at an elution volume of 22 x 0.65 mL = 14.3 mL.) Assuming that ferritin is eluted at the interstitial volume and that ferric citrate is eluted at VM, find Kay for transferrin. Kay =arrow_forward(a) You measure the percent transmittance of a solution containing chromophore X at 400nm in a 1-cm path length cuvette and find it to be 50%. What is the absorbance of this solution? (b) What is the molar absorptivity of chromophore X if the concentration of X in the solution measured in question (a) is 0.5mM? (c) What is the concentration range of chromophore X that can be assayed if, when using a sample cell of path length 1, you are required to keep the aborbance between 0.2 and 0.8?arrow_forward
- Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning