GCMS for perfumes

[srinag]

Good morning everyone, as the topic suggests I'm curious about analyzing perfumes on the GCMS....

I am completely NEW to the concepts of GC and MS, I hold an engineering degree in computer science, but because of my job I had to learn about GCMS.

I am using a brand new Shimadzu QP2010 ultra and have been given a 3 day crash course on GCMS principles and the machine usage, so it is
still a little bit hazy and I'm trying to get a hang of it.

Currently, the library I'm using is the FFNSC v1.3 and according to that each run should roughly take >=60min. But, I know that this machine can generate just
as good a result in a shorter period of time (<=40min).
So, I am wondering what would be the ideal GC settings (Carrier gas pressure, total flow, column flow, linear velocity, etc) with respect to analyzing perfumes??
Also the various temperatures involved (injection temp, interface temp, etc)???

And in general, any advice with respect to analyzing perfume samples will be greatly helpful and appreciated.

Thanks in advance.

[Consumer Products Guy]

Fragrance analysis can be challenging, as a fragrance can easily consist of 100 components, and not all of those are pure. If you are only interested in the major components, a shorter run time would suffice. But when we assay for essentially all fragrance components, we do a 70 minute run, with slow heating rate.

We made our own GCMS fragrance library in the 1990s.

[srinag]

Fragrance analysis can be challenging, as a fragrance can easily consist of 100 components, and not all of those are pure. If you are only interested in the major components, a shorter run time would suffice. But when we assay for essentially all fragrance components, we do a 70 minute run, with slow heating rate.

We made our own GCMS fragrance library in the 1990s.

Hmmmm, ok, I'll take your advice. I can create 2 method files; 1 for short analysis and another for longer and more thorough analysis.
I guess I'll experiment with different heating rates and find the ideal 1 for my machine. But what about the GC and MS parameters?? Any advice ragarding that???

Thanks for you answer, it is definitely useful.

P.S: If I may ask, which company do you work for?

[yangz00g]

I don't quite understand why you want to jump on method improvement right away before you get some degree of understanding of what GC and MS are. It may be a common thought of newcomers: most of them believe GC-MS is so simple that they can master it in a matter of a few days or weeks after some showing.

GC-MS is not as easy as you were showed, library matching is more difficult than you can think of. It usually takes an experienced chemist a few days to go through a complex perfume. There are lost of mismatches, you need have enough know-how of general perfume formulations to get the components identified right.

[PaulDDodson]

Dear Srinag,
The basics of running fragrances by GC/MS are pretty much all the same for each manufacturer of benchtop GC/MSs. Just keep in mind that you really don't need to dilute the sample (usually) you need at least a 60 meter column (preferably a DBS-5 i.e. 5% phenylated ploydimethylsiloxane) with a small diameter of 0.25mm or even less (make sure the manufacturer of the column says MS after the DB5 because otherwise the column "bleeds" too much for the MAss spectrometer. Injector temp should be sround 250C, column oven ramo from 60 slowly ramped to 250 -or even more and the transfer line temp needs to be at least 20C higher than the highest oven temp in your run to keep any of your highest boiling components from crystallizing in it. The Trap Ion source at about the same temp as the transfer line. Make sure you split the sample at least 100:1 and really probably 200:1 or you will get column overload (it don't take -nothin- to overload the column (very poor peak shape). Hope that helps.-Paul