Gas Chromatography Lab Report

2583 Words11 Pages
Introduction: Gas chromatography is an instrumental method for the separation and identification of chemical compounds. Chromatography involves a sample (or sample extract) being dissolved in a mobile phase (which may be a gas, a liquid or a supercritical fluid). The mobile phase is then forced through an immobile, immiscible stationary phase. The phases are chosen such that components of the sample have differing solubility’s in each phase. A component that is quite soluble in the stationary phase will take longer to travel through it than a component that is not very soluble in the stationary phase but very soluble in the mobile phase. As a result of these differences in mobility, sample components will become separated from each other as they travel through the stationary phase. The diagram of the separation process is shown on the Figure 1. The time between sample injection and an analyte peak reaching a detector at the end of the column is termed the retention time (tR ). Each analyte in a sample will have a different retention time. The time taken for the mobile phase to pass through the column is called tM. Development of analytical method gas chromatography The number of drugs introduced into the market is increasing every year. These drugs may be either new entities or partial structures modification of…show more content…
Isothermal temperature conditions are used for solutes with similar retention. Retention differences for dissimilar solutes can be quite severe for isothermal temperature conditions. Peak widths rapidly increase with retention for isothermal conditions. For these reasons, isothermal temperature conditions are only suitable for a limited number of analyses. For example figure no 11 is isothermal temperature for as temperature programming chromatogram for n- alkanes on conditions of DB-1, 15 m x 0.25 mm i.d., 0.25 μm,100°C; Helium at 30 cm/sec

More about Gas Chromatography Lab Report

Open Document