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Reverse-phase high-performance liquid chromatography (HPLC) uses a non-polar stationary phase together with a polar mobile phase - VCE - SSCE Chemistry - Question 5 - 2009 - Paper 1
Question 5
Reverse-phase high-performance liquid chromatography (HPLC) uses a non-polar stationary phase together with a polar mobile phase. Which of the following molecules w... show full transcript
Worked Solution & Example Answer:Reverse-phase high-performance liquid chromatography (HPLC) uses a non-polar stationary phase together with a polar mobile phase - VCE - SSCE Chemistry - Question 5 - 2009 - Paper 1
Step 1
Which of the following molecules will have the greatest retention time on such a reverse phase column?
Answer
In reverse-phase HPLC, a non-polar stationary phase and a polar mobile phase result in longer retention times for non-polar or less polar molecules. Among the options:
- Option A: Is a linear alkane (non-polar) and would have lower retention time.
- Option B: Contains a polar hydroxyl group and an amino group which introduces significant polarity.
- Option C: Also has a hydroxyl group, making it more polar than a typical hydrocarbon.
- Option D: Similar to C, has a hydroxyl group making it polar.
Considering these factors, Option B is expected to have the greatest retention time due to its combination of hydrophobic (alkane) and polar functional groups, balancing between solubility in the non-polar stationary phase and interaction with the polar mobile phase.