Gas Chromatography: Polar Compounds & Retention Time

In summary, when using a liquid stationary phase, the rule of "like dissolves like" applies, meaning that the chosen stationary phase must be polar if the compound of interest is polar. The retention time of the compound is affected by interactions with the stationary phase, with polar compounds being eluted faster if the solvent is also polar. It is also possible for polar compounds to interact with each other.
  • #1
sotellme
75
0
it says when i choose the liquid stationary phase, then i have to use the rule; "like dissolves like". i wonder if the compound i am interested in is polar, this means that the stationary phase i choose must also be polar, right? how would you predict the retention time of my compound? would it be eluted faster or slower than other nonpolar compounds?


BTW how can polar compounds be interacted with each other?

thanks again! :smile:
 
Chemistry news on Phys.org
  • #2
Retention time involves some interactions between solute (your compound dissolved in a solvent) and the stationary phase. The high polarity of solvent drives your spot faster if your compound is also polar; and vice versa (like dissolves like principle).
 
  • #3
thanks alot!
 

What is gas chromatography?

Gas chromatography is a technique used to separate and analyze mixtures of compounds. It involves passing a gaseous sample through a column containing a stationary phase and a mobile phase. The compounds in the sample will interact differently with the stationary phase and will be separated based on their physical and chemical properties.

What are polar compounds?

Polar compounds are molecules that have an uneven distribution of charge due to the presence of polar covalent bonds. This means that one part of the molecule has a slight positive charge and another part has a slight negative charge. These compounds are attracted to other polar molecules and can interact with the stationary phase in gas chromatography.

Why is retention time important in gas chromatography?

Retention time is the amount of time it takes for a compound to pass through the column and reach the detector in gas chromatography. It is an important parameter because it can be used to identify compounds based on their unique retention times. Retention time is influenced by factors such as compound polarity, column temperature, and mobile phase flow rate.

How are polar compounds retained in gas chromatography?

Polar compounds are retained in gas chromatography through interactions with the stationary phase. These interactions can include dipole-dipole interactions, hydrogen bonding, and polar-polar interactions. The strength of these interactions will determine how long the compound stays in the column, and therefore, its retention time.

What factors can affect the retention time of polar compounds in gas chromatography?

Several factors can affect the retention time of polar compounds in gas chromatography. These include temperature, flow rate, column length, and stationary phase properties. Additionally, the chemical structure and polarity of the compound itself can also influence retention time. It is important to optimize these parameters to obtain accurate and reliable results in gas chromatography.

Similar threads

Replies
1
Views
2K
Replies
4
Views
1K
  • Biology and Chemistry Homework Help
Replies
4
Views
2K
Replies
1
Views
6K
Replies
1
Views
2K
  • Chemistry
Replies
7
Views
7K
Replies
4
Views
1K
Replies
8
Views
9K
  • Atomic and Condensed Matter
Replies
4
Views
1K
Replies
4
Views
1K
Back
Top