Limitation Of Gas Chromatography

Step 5-Data analysis:
A computer based data system like the open lab chemical data system is used to process digitalized data signal and uses various mathematical calculations to determine peak areas, peak heights peak width and retention time.
The chromatograph is the graphical representation of the sample elution and response complete. Each peak is identified by specific time that it leaves the column and passes through the detector called the retention time.
The first peak is usually the solvent peak which is often very large and saturates the detector. The first component reaches the detector and the peak is displayed on the integrator.
Retention times are used to identify the components in a mixture by comparing same peak times to known

>Unit of parts per million range.
>Environmental distraction, especially water vapor.
>Strong electrical fields, rapid variation in temperature at the detector and naturally occurring compounds may affect instrumental signal
Gas Chromatography/Mass Spectroscopy: The gas chromatography device is generally a reliable analytical instrument. The gas chromatography instrument is effective in separating compounds into their various components. However, it cannot be used for reliable identification of specific substances. The mass spectroscopy instrument provides specific results but produces uncertain qualitative results. When an analyst uses the gas chromatography instrument to separate compounds before analysis with a mass spectroscopy instrument, a complementary relationship exists. The technician has access to both the retention times and mass spectral data. Many scientists consider GC/MS analysis as a tool for conclusive proof of identity. GC/MS analysis, where the effluent to the gas chromatography instrument is the feed to the mass spectroscopy instrument, is in wide use for confirmation testing of

Most of the time, air quality control units use GC coupled with FID in order to determine the components of a given air sample. Although other detectors are useful as well, FID is the most appropriate because of its sensitivity and resolution and also because it can detect very small molecules as well.
GC/MS can determine the components of a given mixture using the retention times and the abundance of the samples. This method be applied to many pharmaceutical applications such as identifying the amount of chemicals in drugs. Moreover, cosmetic manufacturers also use this method to effectively measure how much of each chemical is used for their products. Drug testing, manufacturing quality control, and environmental testing are some typical uses.
Gas Chromatography is used extensively in forensic science. Disciplines as diverse as solid drug dose (pre-consumption form) identification and quantification, arson investigation, paint chip analysis, and toxicology cases, employ GC to identify and quantify various biological specimens and crime-scene