I think that's a basic question for a chemist, but I couldn't find any info online.
Let say I know the mass ion abundance of a certain compound in 1 liter of air (a jar for instance). I know to molecular mass of that compound as well.
How can I convert it to ppm?
Thank you,
Mr. Dror,
There are plenty of literature in this context: relations MS intensity - analyte concentration.
Barak,
you need a calibration! (to link your abundance with known concentration of the analyte).
Read about external standard method (calibration curve) or standard addition method. If it will be a routine applciation think about internal standard method.
Check my papers - there you will find detailed explanation of the procedures used for quantitative analysis by GC-MS.
regards,
G
Hi Barak Dror,
What do you mean by "mass ion abundance" ? Ion abundance is a term typically used in mass spectrometry as a measure of signal intensity.
If you are talking about a mass (i.e. grams or kilograms) of a specific ion in a determined volume (say 1 liter) then that's easier to solve. You have to convert your units of mass to a millionth of the units of your volume e.g:
To convert 3 g/L (3 grams of substance in 1 liter of air) you need to convert 3g into milligrams (3g = 3000mg) and you'll have 3000 mg/L which is equal to 3000 ppm.
1 liter is equivalent to 1 million milligrams, so you have 1 part ( 1 mg ) per million ( 1 million mg = 1 L)
Thank you all, that was enlightning.
However, the data I have is from papers I read, so I don't have standards to use, only the data they publish. The results are given as mass ion abundance.
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