No. "MS" is not a universal detector and not the preferred detector for quantitation. Sometimes the MS detector does not even "detect" samples which may in fact be present in the sample, so caution must be used. *These are fundamental facts which must be understood by anyone using the technique.

Peak area values are dependent on many factors including: the exact GC method used, the instrument settings (GC and MS), operator training, sample preparation, sample type (as sample type impacts MS output) and many other parameters. Only through a scientifically developed GC-MS method which follows good fundamentals, using standards with full calibration levels for each compound to show what relationship the signal output (response) has to the 'area' counts (and using orthogonal techniques for verification) can any relationship between signal output (e.g. area percent) and concentration be shown.

thanks for your answers

In my work, I aim to determine the Higher Heating Value (HHV) of the pyrolysis liquid of a plastic based on the results of the GC-MS analysis by summing the HHV of each detected compound (hydrocarbon) weighted by its mass fraction, which is considered to be the percentage of the peak area.

Not directly, no - you need calibration from standard mixtures.

How to identify compound using retention time in the chromatogram of GC-MS. Please help

Anish Kuttipalackal Vijayan : (1) Please do not hijack another users thread. If you have a question, then please create a new post (proper forum etiquette). (2) Retention time (Rt) alone is just one dimension of analysis and not enough to make an ID. The retention time observed only applies to YOUR method on YOUR instrument. To make a qualitative ID using GC-MS (EI) in a sample, you may be able to use one of the many EI library files in your GC-MS software to suggest possible matches. The ion fragments obtained for the peak may suggest a compound name and this could be checked by ordering the standard, then re-injecting it your method on the same instrument (compare resulting data). Additional orthogonal techniques/modes will be needed for verification. Please ask your teacher or the chromatographer in charge of the instrument for assistance. If you have additional questions, please create a new thread under your name.