10. A racemic mixture of (R)- and (S)- citalopram (figure 4) needs to be separated by liquid chromatography and detected. The separation is achieved with reversed phase chromatography. Figure 4 F F H3C N-CH3 -CH3 H3C Answer ALL parts of this question. a) Discuss whether the enantiomers in Figure 4 are fluorescent and if so whether fluorescence can help to differentiate them. b) Discuss whether the enantiomers in Figure 4 will have a signal in Raman spectroscopy, and if so, whether the Raman spectra can help to differentiate them. c) Describe the experimental conditions that would be needed to attempt their separation with ion pair chromatography. d) Propose an alternative technique to ion pair chromatography for the fast separation of both molecules in Figure 4.

Z and E -oct-3-en-2-ol is hard or easy  to separate in thin layers in chromatography?

a. Say you are trying to separate two compounds by column chromatography. You run a column and collect the eluent in five fractions. You analyze each fraction by TLC on the same plate (shown below). Based on the TLC plate, how effective was your separation? Consider the purity of each fraction. - - - - - - - - ----| 1 2 3 4 5

What would happen to the retention time of a compound if the following changes were made? Sketch the chromatogram of this mixture for the following questions (a, b and c). "10א2s 2.5 1.5- 0.5 -05 4.2 4.6 5.2 54 5.6 5.8 Time (s) a. Increase the flow rate of the carrier gas b. Decrease the temperature of the column c. Decrease the length of the column Intensity (arb, units)

The following chromatographic peaks indicate the undesirable interaction and separation that taken place. Explain in detail how these undesirable interaction and separation happen for each chromatographic peak. b с d a

In the diagram of TLC for column chromatography, What does light faded looking spots (less or less product, etc.)? Which fractions contain the product? concentrated 1 2 3 4 14 26 15 27 16 28 17 29 5 6 7 8 18 19 30 31 32 20 33 9 21 10 22 11 23 12 13 24 25 34 35 36 37 38

Which one is the more polar component? Explain.

2) Consider the following compounds. Which rankings list these compounds in terms of Rf from lowest to highest using a silica gel thin layer chromatography plate and 1:1 Ethyl Acetate:Hexanes as the developing solvent. (e. g. A