INSTRUMENTAL ANALYSIS EXAM - Assignment Example

The Following is the equation showing all the variables: The theoretical application of the equation is mostly observed High Perfomance Liquid Chromatography especially in the separation of similar simple hydrocarbons. Another practical application is in separation of amino acids, and proteins. In split injection for GC, the major purpose is to ensure most of the sample do not flow into the column but instead they pass through the split vent on their way to the atmosphere. This is unlike splitless injection whereby most of the sample volatize and flow into the column.

In which case, for split injection the split vent is normally open while for splitless, the vent is closed by a split valve controlled by a computer. The ideal situation for using split injection is when there is need to achieve rapid volatilization besides homogenous mixing of the injected sample with a carrier gas. For splitless mode, an ideal scenario for its use is where there is need to slow down the volatization of the sample. Application: impurity profiling and exploration of degradation.

In which case, the gradient flow is used for complex samples with analytes of wide polarities and commonly used for high throughput screening and impurity testing; such as in impurity profiling. The reversed phase makes the use of a polar mobile phase and a non-polar [hydrophobic] stationary phase. Those compound having similar polarity as that evident in mobile phase will be preferentially attracted to it and move faster. For compounds having similar polarity to that of non-polar stationary phase there movement will be delayed because of their strong attraction to the particles.

Intuitively, the differences in the relative attraction of each compound for each phase creates a basis for separation by changing the speeds of the analytes. Particle size (dp), is a representation of the mean diameter of the spherical supports used to pack a column. According to the definition,