Interpretation of chromatogram

In summary, the conversation involved determining the Number Average Molecular Weight and Weight Average Molecular Weight of two samples using Gel Permeation Chromatography in a polychemistry laboratory. The first sample was a polystyrene prepared by radical polymerization, while the second sample was a polystyrene-block-isoprene polymer prepared by anionic polymerization. The GPC software generated an elugram and weight distribution for each sample. The homework equation PDI = Mw/Mn was also mentioned, and there was a link to a plot for the second sample which showed a small peak to the right of the main peak, representing the Copolymer. However, there was confusion about how this peak was related to the synthesis and Molecular Weight
  • #1
selseg
32
0
1.
In my polychemistry laboratory , the task was to determine the Number Average Molecular Weight and the Weight Average Molecular weight of two samples , one a polystyrene sample prepared by radical polymerization , and the other a polystyrene-block-isoprene polymer prepared by anionic polymerization.Using Gel Permeation Chromatography . The GPC software generated an elugram and a weight distribution for each sample.

Homework Equations


PDI = Mw/Mn[/B]
This is the link to the plot https://docs.google.com/file/d/0Bw0SjzcEyj3GeTBIZ1NLanJuOWs/edit?pli=1 https://docs.google.com/file/d/0Bw0SjzcEyj3GeTBIZ1NLanJuOWs/edit?pli=1

The Attempt at a Solution


The plot for the first sample is easy to inteprete since it has a broad distribution .The plot for the second has another small peak to the right of the main peak , which I understand is the Copolymer .However I don't understand how that peak came about in relation to synthesis and Molecular Weight [/B]
 
Physics news on Phys.org
  • #2
Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
 

What is a chromatogram?

A chromatogram is a graphical representation of the components of a mixture separated by chromatography. It shows the peaks of separated compounds and their retention times, which can be used to identify and quantify the components present in the mixture.

What is the purpose of interpreting a chromatogram?

The interpretation of a chromatogram is important for identifying the components of a mixture and determining their relative concentrations. This information can be used for various purposes, such as quality control, forensic analysis, and research in fields like pharmaceuticals and environmental science.

How is a chromatogram interpreted?

A chromatogram is interpreted by analyzing the peaks and retention times of the separated compounds. The retention time is the time it takes for a compound to travel through the chromatography column, and it is unique for each compound. By comparing retention times with known standards, the compounds can be identified.

What factors can affect the interpretation of a chromatogram?

Several factors can affect the interpretation of a chromatogram, including the type of chromatography used, the composition and concentration of the sample, and the quality of the separation. Other factors such as temperature, flow rate, and column condition can also impact the results.

What are some common challenges in interpreting a chromatogram?

Some common challenges in interpreting a chromatogram include overlapping peaks, baseline noise, and poor resolution. These issues can make it difficult to accurately identify and quantify the components in a mixture. It is important to carefully consider these factors and use proper techniques to minimize their impact on the interpretation of the chromatogram.

Hot Threads

Recent Insights

Back
Top