Smi-quantitative analysis

[chemomet78]

Hi,
I'd like to get some references about semi-quantitative analysis (How to do it). I use 3 internal standards within my samples, and I'm planning to perform semi-quantitative analysis. are there different ways to do that?

Regards

[sassman]

Please give some more details. What compounds are you analyzing? What instrument are you using? Detector? Sample dissolved in what solvent? Method parameters? You have internal standards, but will you also use external standards? In my mind, semi-quantitative is a relative term. So you want to get some numbers, but don't need great accuracy?

[chemomet78]

I use 2D-GC-TOF for the anlysis of wine samples. I don't use external standards, I just use three internal standards (alcohols and ketone).

[Don_Hilton]

If your peaks are well resolved, use the TIC. If you collect signal for the lower masses in the spectrum, this will do a good job of giving you areas that are roughly proportional to the concentrations of compounds present.

Beyond that I'd have to know which GC-TOF data analysis program you are using. There is the software that comes with the instrument and some people are using third party software.

If you are using a LECO Pegasus, I am willing to look at a data file or two to see if I can help you out. (I have to do this at home rather than at work - so I can not look at many files.) My e-mail is shown in my profile and at the bottom of this posting.