Chromatography Forum

İf anybody who use, a Chromatography (and related with a mass spectrometer) equipment, shortly, GC/MS, about experience, giving to it sample and evaluation of its results, can share ? How is the preparation to analysis? and evaluation ?
Thanks already..
If there are mistakes in my Enghlish,sorry.It's not my first language.I wanted to explain clearly.

If I understand your question, you want to know how to prepare a sample for GC/MS analysis and something about evaluation of the results?

If I understand your question correctly, it takes many books to answer the question - too much to post on this site. Sample preparation depends entirely on what the sample is and what you want to know about it. Likewise, the evaluation of results depends on what you want to know about the sample.

I'm working in a company which generatig mineral oils and similar.So, samples are generally oils. We want to control incoming raw materials(base oil) with GC.I wonder whether it is really the base oil that I'm looking for.Our equipment also have library on.
Thaks for answering question.

Petroleum samples are quite varied and complex. Crude oils take some sample preparation to remove compunds like asphaltenes. Refined fractions can be analyized directly. Analysis for specific types of compunds may require sample preparation to concentrate them.

Having a library when analyzing petroleum samples is of some value - but many compunds look similar to each other and may be confused with each other. Also, there are many compunds in petroleulm that have never been included in commerically available libraries - so they will not be identified correctly by searching against those libraries. Use of relative retention times will be required. Some experieince with chromatography and mass spectroscopy and some knoledge of petroleum chemistry is strongly suggested before attempting to identify unknown compounds.

Depending on what you are trying to control about your base oils, you may wish to look at the ASTM methods for petroleum analysis. These methods provide a lot of important information and have already been developed.