Kendrick mass defect (KMD) analysis

Discuss with developer team, share useful tips, report bugs, request new features and anything else
Post Reply
leowang
Posts: 5
Joined: March 28th, 2018, 5:45 am

Kendrick mass defect (KMD) analysis

Post by leowang » May 5th, 2021, 7:01 am

Dear All:

The kendrick mass defect (KMD) analysis is performed for the mass peaks of the active spectrum only?

Users' Guide: "The table, on the right, shows the exact mass, mass defect, and intensity for each peak."

In petroleomics, we typically use the KMD analysis for all molecular ions (or adduct ion) of the active chromatogram. By limiting this function to the active spectrum only, data visualization becomes limited. Is there a way to use KMD analysis for the entire blob table simultaneously?

Take care,

Leo

qtao
Posts: 172
Joined: October 7th, 2011, 10:16 am

Re: Kendrick mass defect (KMD) analysis

Post by qtao » May 5th, 2021, 10:55 am

For the entire chromatogram, a polygon area can be created first, then the Area spectrum can be open to generate the KMD plot.

Also, you may filter noises by limiting the targeted region and the number of ions to be plotted. For example, a polygon can be created based on TIC, and Ordinal Limit is set to 1000 as shown below:

Image

leowang
Posts: 5
Joined: March 28th, 2018, 5:45 am

Re: Kendrick mass defect (KMD) analysis

Post by leowang » May 5th, 2021, 12:39 pm

Hi,

I created the polygon and selected the 'include' checkbox. How do I use the 'Area Spectrum' feature?

qtao
Posts: 172
Joined: October 7th, 2011, 10:16 am

Re: Kendrick mass defect (KMD) analysis

Post by qtao » May 6th, 2021, 10:40 am

Check the Area box instead of the Included box. Then, switch to the Blob/Area MS mode, and click the area as shown below:

Image

Note that it may take a while for the software to display the spectrum since it needs to integrate all spectra within the area.

Post Reply