The Objectives And Advantages Of Gas Chromatography

September 27, 2011 Organic Chemistry: Introduction to the various forms of chromatographs that will be encountered throughout the study of Chromatography.

The core of this discipline is to perform the scientific study of structure, composition and properties of carbon based compounds. The ability to separate and isolate the molecules is achieved through various highly technical pieces of equipment such as chromatographs and the techniques know as chromatography. Some of the many forms which may be encountered are paper, thin-layer, and for our purposes here today gas.

These methods allow the lab technicians to separate the components of the mixture and quantify the amounts. For example a future experiment may ask you to separate the mixture of four isomeric butyl alcohols and determine the percentage of each component present. To achieve these results, gas chromatography would have to be incorporated due to the volatile nature of the sample.

Focusing on the basics of gas chromatographs we will demonstrate its functions and how to obtain a proper reading. This particular experiment will use a Buck Model 910 Chasis GC, www.bucksci.com, in mind when describing the technique necessary.


Place a small amount of the sample, in this case the alcohol, to be analyze in the syringe given and then place in the injector port. Here the machine will react at higher temperatures than the boiling points of the sample. At this point the components of the mixture will evaporate into gas to be separated and analyzed. Assisted by what is known as a carrier gas, in this case helium the sample will be taken through the GC column where the separation will take place. The molecules will partition between the carrier gas (the mobile phase) and the high boiling liquid (the stationary phase) within the GC column.

Once the various components move through the column they will reach the detector along with a data processor within all gas chromatographs that will provide a reading. The objective is to have the various components of the mixture to pass through the detector at varying times stages due to the portioning between mobile and stationary phases. A signal is sent form the detector to the data processor in the form of a peak on the read out, the peak will directly correlate to how much of the molecule is present. Gas chromatography is essential in process of studying how carbon components are separated and how they function amongst one another.

Analyzing the data produced form this equipment will help students perform experiments that will lead to new research and further data collection. The proper use of this equipment will lead to precise readings and correct data collection and the misuse will accomplish the opposite.