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Chapter 25: Q6P (page 707)

a. Why are HPLC particles porous?

b. Why are the particles with60-120A°pores used for small molecules but wide pore300-A°stationary phases used to separate polypeptides and proteins?s

Short Answer

Expert verified

The porous HPLC particles increase the surface area, resulting in greater sample capacity.

Smaller pore stationary phases are used for small molecules, but wide pore stationary phases are used to separate polypeptides and proteins because the pores must be large enough for the dissolved substances to enter. Larger pores take up more surface area, so they should be avoided if possible.

Step by step solution

01

Step 1:Explanation

For part a, Because porous HPLC particles increase surface area, they have a higher sample capacity.

02

Explanation

For part b, Smaller pore stationary phases are used to separate small molecules, whereas wide pore stationary phases are used to separate polypeptides and proteins because the pores must be large enough for the dissolved substances to enter. Because larger pores take up more surface area, they should be avoided if possible.

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Most popular questions from this chapter

what is the difference between extra-column volume and dwell volume? How do each of these volumes affect a chromatogram?

Question: Explain how to use a gradient for the first run to decide whether isocratic or gradient elution would be more appropriate.

The chromatogram in Box 25-3 shows the supercritical fluid chromatography separation of seven steroids monitored by three detectors.

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