Chromatography Forum

Hi

I am very much new to this forum and also using GC Chromatography without headspace. We had a basic GC Chromatography training. Our company produces IPA 70% solution and Denatured ethanol ( Ethanol denatured with 5 % of Isopropanol 100% ) 70% solution.
we got Nitrogen , hydrogen and air as gases in our Instrument.

We have to analyse qualitative and quantiatively the raw materials (raw material - 1 Isopopyl alcohol 99.7% and raw material - 2 Ethanol 95% + isopropanol 5% used to make products and also the 70% diluted ones.

i got no clue where to start in this process. Can anybody help me with this.

any information on this would be quiteful.

thanks and regards
deepthi

Welcome to the forum.

The place to start is with your company's in-house documentation of the methods. Just follow them.

Peter

Hi peter

Thanks for your reply

We recently introduced GC into our analysis system. We haven't got any history of GC documentation

This is a tricky problem, you have a new GC lab, and you "have no clue where to start".

Reading between the lines - you do know how to run the GC and the software, but have experience only with headspace injections ?

Have you looked up any methods for your products in the literature, or on the internet ?

Peter

Yes you are right . I have done a project in my masters related to GC and haven't got any further experience in that. We haven't got headspace injector . Manual injector only.
I have gone through online sources . I can find all for blood related samples . USP pharmacoepia gave for any impurities in IPA like benzene that too with helium gas but we use Nitrogen gas .
I got stuck, please help me by any chance

Thanks and regards
Deeptgi

This is not the kind of problem that can be solved over the internet. The best advice that I can give is for you to contact the suppliers of the instrument and ask them for methods for your analysis. They can advise on which columns you need and operating conditions, and train you how to install columns and do routine maintenance. Try searching the internet for analysis of solvents - as you have found just entering the names of the chemicals gets you lots of information that is not relevant. Look in the application notes section of the instrument and column maker's web sites as well.

Good luck.

Stick around though, someone with specific experience on these materials might post something.

Peter

Hello,
this is a general comment. Since the work you are doing is for a company it is best to used a
method that has already been peer reviewed and certified, otherwise you have to do the entire
method validation procedure, which is very involved. The most recognised methods are e.g. US EPA methods.
, which would make the Certificate of Analysis that you would generate, readily traceable and acceptable by your customers.

As for using Nitrogen (maybe Hydrogen for better resolution? Safety Issues!), and not Helium, as the carrier gas,
Agilent has a guide
http://www.chem.agilent.com/Library/sli ... drogen.pdf

and to support Peter's statement, this is not something simple, it is actually very extensive.