Calculating the mass % from GC-MS peak area.

[GC-td123]

Hi

The last row in the below table represents the GC-MS peak area % of different compounds. Is it possible to calculate mass % of the compounds from the GC-MS peak area %?.

How do we calculate mass %, if the sample contains several compounds?


peak R.T. first max last PK peak corr. corr. % of
# min scan scan scan TY height area % max. total
--- ----- ----- ---- ---- --- ------- ------- ------ -------
1 1.266 27 30 42 PV 814190 7953291 2.59% 0.576%
2 1.361 42 45 57 PV 2668510 26734157 8.70% 1.936%
3 1.469 57 63 70 PV 2 1389933 37432591 12.19% 2.710%
4 1.525 70 73 79 VV 1618073 18999414 6.19% 1.376%
5 1.954 79 144 155 VV 3380277 307129642 100.00% 22.236%

6 2.059 155 161 173 PV 5631411 81559860 26.56% 5.905%
7 2.203 173 185 192 VV 113488 2966303 0.97% 0.215%
8 2.331 192 206 212 PV 281227 4253436 1.38% 0.308%
9 2.434 212 223 243 VB 2 280856 7871431 2.56% 0.570%
10 2.706 253 268 274 PV 1347139 18481713 6.02% 1.338%


Thanks for your time.

[rb6banjo]

No. The area percent for an individual component is the peak area for that component divided by the summed areas of all of the peaks in the chromatogram. Not all components respond the same way in any detector so you can't do it. Boy, it'd make calibration a lot easier if you could.

To get at your "Mass %", you'd have to calibrate (determine the response factor) for every component in the mixture.

[GC-td123]

Hi
thanks for the reply.

Please have a look on the calculation example on the following link.
https://socratic.org/questions/how-do-y ... matography

In that example, the mole % was calculated from half-width peak area %. If we know the mole %, then we can convert it into mass percentage.

Can I use the same method to calculate the mole % from half-width peak area %, if I have more than 50 compounds in a sample?

[rb6banjo]

Nope. Sorry. That person knows just enough to be dangerous. His/her argument assumes that all analytes respond the same in the detector of choice. That is not the case. Be very careful about using answers from those types of Q and A forums. Lots of times, the well-wishing responders really have no idea what they're talking about.

I see that you posed your question in the GCMS forum and received a similar answer to mine from a different source. Generally, we all read all of these forums so you only need to post your query once. Good luck!